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Science of Science Communication 2.0, Session 8.1: Emerging technologies part I

Wow--time flies, doesn't it? Especially when every other week of class is cancelled due to snow.

But in any case-- it's that time again!  "Science of Science Communication 2.0" session 8 reading list here, & study/discussion questions below.  

Have at it!


Weekend update: Science of Science Communication 2.0: on CRED "how to" manual & more on 97% messaging

Here are some contributions to class discussion.  The first is from Tamar Wilner, who offers reactions to session 7 readings.  I've posted just the beginning of her essay and the linked to her page for continuation. The second is from Kevin Tobia (by the way, I also recommend his great study on the quality of "lay" and "expert" moral intuitions), who addresses "97% messaging," a topic initially addressed in Session 6 but now brought into sharper focus with a recently published study that I myself commented on in my last post.

Health, ingenuity and ‘the American way of life': how should we talk about climate?

Tamar Wilner

Imagine you were

  1. President Obama about to make a speech to the Nation in support of your proposal for a carbon tax;
  2. a zoning board member in Ft. Lauderdale, Florida, preparing to give a presentation at an open meeting (at which members of the public would be briefed and then allowed to give comments) defending a proposed set of guidelines on climate-impact “vulnerability reduction measures for all new construction, redevelopment and infrastructure such as additional hardening, higher floor elevations or incorporation of natural infrastructure for increased resilience”;
  3. a climate scientist invited to give a lecture on climate change to the local chapter of the Kiwanis in Springfield, Tennessee; or
  4. a “communications consultant” hired by a billionaire, to create a television advertisement, to be run during the Superbowl, that will promote constructive public engagement with the science on and issues posed by climate change.

Would the CRED manual be useful to you? Would the studies conducted by Feygina, et al., Meyers et al., or Kahan et al. be? How would you advise any one of these actors to proceed?

First, some thoughts on these four readings.

The CRED Manual: well-intentioned, but flawed2015-02-27_10-42-04

Source material: Center for Research on Environmental Decisions, Columbia University. “
The Psychology of Climate Change Communication: A guide for scientists, journalists, educators, political aides, and the interested public.”

When I first read the CRED manual, it chimed well with my sensibilities. My initial reaction was that this was a valuable, well-prepared document. But on closer inspection, I have misgivings. I think a lot of that “chiming” comes from the manual’s references to well-known psychological phenomena that science communicators and the media have tossed around as potential culprits for climate change denialism. But for a lot of these psychological processes, there isn’t much empirical basis showing their relevance to climate change communication.

Of course, the CRED staff undoubtedly know the literature better than I do, so they could well know empirical support that I’m not aware of. But the manual authors often don’t support their contentions with research citations. That’s a shame because much of the advice given is too surface-level for communications practitioners to directly apply to their work, and the missing citations would have helped practitioners to look more deeply into and understand particular tactics.

continue reading


“Gateway beliefs” and what effect 97% consensus messaging should have

Kevin Tobia

A new paper reports the effect of “consensus messaging” on beliefs about climate change. The media have begun covering both this new study and some recent criticism. While I agree with much of the critique, I want to focus on a different aspect of the paper, the idea of a “gateway belief.” Thinking closely about this suggests an interpretation of the paper that raises important questions for future research – and may offer a small vindication of the value of 97% scientific consensus reporting. You be the judge.

First, what is a “gateway” belief? In this context, what is it for dis/belief in scientific consensus on climate change to be a “gateway” belief? You might think this means that some perceived level of scientific consensus is necessary to have certain beliefs in climate change, worry in climate change, belief in human causation, and support for public action. You can’t have these beliefs unless you go – or have gone – “through the gate” of perceived scientific consensus.

But here’s what the researchers actually have to say about the “gateway” model prediction:

We posit that belief or disbelief in the scientific consensus on human-caused climate change plays an important role in the formation of public opinion on the issue. This is consistent with prior research, which has found that highlighting scientific consensus increases belief in human-caused climate change. More specifically, we posit perceived scientific agreement as a “gateway belief” that either supports or undermines other key beliefs about climate change, which in turn, influence support for public action. ... Specifically, we hypothesize that an experimentally induced change in the level of perceived consensus is causally associated with a subsequent change in the belief that climate change is (a) happening, (b) human-caused, and (c) how much people worry about the issue (H1). In turn, a change in these key beliefs is subsequently expected to lead to a change in respondents’ support for societal action on climate change (H2). Thus, while the model predicts that the perceived level of scientific agreement acts as a key psychological motivator, its effect on support for action is assumed to be fully mediated by key beliefs about climate change (H3). 

There are a couple things worth noting here. First, if the ultimate aim is increasing support for public action, you don’t have to go “through the gate” of the gateway belief model at all. That is, what is really doing the work is the set of (i) beliefs that climate change is happening, (ii) beliefs it is human-caused, and (iii) how much people worry about it. If we could find some other way to increase these, we could affect public support without needing to change the perceived level of science consensus (though, whether that change might itself affect the perceived level of scientific consensus is another interesting and open question).

Second – and more importantly – it is not the case that there is some “gateway belief” in perceived scientific agreement that is required to have certain beliefs in climate change or human causation, worry, or support for action. The model merely predicts that all of these are affected by changes to the perceived level of scientific agreement. Thus, it is incorrect to draw from this research that the “gateway belief” of perceived scientific consensus is (as analogy might suggest) some necessary or required belief that must be held in order to belief in human-caused/climate change, worry about it, or support for action. Instead, the gateway belief is something like a belief that tends to have or normally has some relation to these other climate beliefs.

When we put it this way, the “gateway belief” prediction might start to seem less interesting: there’s one belief about climate change (perceived consensus among scientists) that is a good indicator of other beliefs about climate change. But, what is more intriguing is the further claim the researchers make: this gateway belief isn’t just a good indicator of others, but increasing the gateway belief will cause greater belief in the others. Perceiving scientific non-consensus is the gateway drug to climate change denial!

This conception of the gateway belief illuminates a subtle feature of the researchers’ prediction. Recall:

we hypothesize that an experimentally induced change in the level of perceived consensus is causally associated with a subsequent change in the belief that climate change is (a) happening, (b) human-caused, and (c) how much people worry about the issue ....

The hypothesis here is that changing the level of perceived consensus causes changes in these other climate beliefs.

Some might worry about the relatively small effects found in the study. But if we recognize the full extent of the researchers’ prediction (that increased perceived consensus will raise the other beliefs AND that decreased perceived consensus will lower the other beliefs), one possibility is that some participants with very high pre-test consensus estimates (e.g. 99% or 100%) actually reduced their estimate in light of the consensus messaging – and that this affected their other beliefs. It might seem unlikely that many participants held an initial estimate of consensus upwards of 97% (even with a pre-test mean estimate of 66.98), but data on this would be useful.

There is a more plausible consideration that also weakens the worry about small effect size: would we really want participants (or people in the world) to change their beliefs about science in exact proportion to the most recent information they receive about expert consensus? To put it another way, the small effect size might not be evidence of the weakness of consensus messaging, but might rather be evidence of the measured fashion in which people weigh new evidence and update their beliefs.

What would be helpful is data on the number (or percent) of participants whose beliefs increased from pre to post test. This would help distinguish between two quite different possibilities: 

  1. very few participants greatly increased their beliefs in climate change after reading the consensus message
  2. many participants moderately increased their beliefs in climate change after reading the consensus message
There is no good way to distinguish between these from the data provided so far, but which of these is true is quite important. If (1) is true, consensus messaging can only be offered as a method to appeal to the idiosyncratic few. And we might worry that the few people responding in this extreme way are, in some sense, overreacting to the single piece of evidence they just received. If (2) is true, this might provide a small redemption of the “consensus messaging campaign.” A little consensus messaging increases people’s beliefs a little bit (and, since this is from just one message, the small belief change is quite reasonable).

Of course, even if (2) is true, much more research will be required before deciding to launch an expensive messaging campaign. For instance, suppose we discover that the climate beliefs of people with very high initial beliefs in consensus (“97+% initial believers”) are actually weakened when they are exposed to 97% messaging. Even if people who are initially “sub-97% initial believers” change their beliefs in light of 97% messaging, we should ask whether this trade-off is beneficial. There are a number of relevant considerations here, but one thought is that perhaps reducing someone’s climate change belief from 100% to 99% is not worth an equivalent gain elsewhere from, say, 3% to 4%. For one, behaviors and dispositions may increase/decrease non-proportionally. 100 to 99 percent belief change might result in the loss of an ardent climate action supporter, while change from 3 to 4 percent might result in little practical consequence. These are all open questions! 


"the strongest evidence to date" on effect of "97% consensus" messaging

There's a new study out on effect of "97% consensus" messaging.

Actually, it is a new analysis of data that were featured in an article published a few months ago in Climatic Change.

The earlier paper reported that after being told that 97% of scientists accept human-caused climate change, study subjects increased their estimate of the percentage of scientists who accept human-caused climate change.

The new paper reports results, not included in the earlier paper, on the effect of the study's "97% consensus msg" on subjects' acceptance of climate change, their climate change risk perceptions, and their support for responsive policy measures.

The design of the study was admirably simple: 

  1. Ask subjects to characterize on a 0-100 scale their "belief certainty" that climate change is occurring, that it is caused by humans, that it is something to worry about, and that something should be done about it;
  2. tell the subjects that “97% of climate scientists have concluded that human-caused climate change is happening”; and
  3. ask the subjects to characterize again their "belief certainty" that climate change is occurring, that it is caused by humans, that it is something to worry about, and that something should be done about it.

Administered to a group of 1,104 members of the US population, the experiment produced these results on the indicated attitudes:

So what does this signify?

According to the authors, 

Using pre and post measures from a national message test experiment, we found that all stated hypotheses were confirmed; increasing public perceptions of the scientific consensus causes a significant increase in the belief that climate change is (a) happening, (b) human-caused and (c) a worrisome problem. In turn, changes in these key beliefs lead to increased support for public action.

I gotta say, I just don't see any evidence in these results that the "97% consensus msg" meaningfully affected any of the outcome variables that the authors' new writeup focuses on (belief in climate change, perceived risk, support for policy).

It's hard to know exactly what to make of  the 0-100 "belief certainty" measures. They obviously aren't as easy to interpret as items that ask whether the respondent believes in human-caused climate change, supports a carbon tax etc.

In fact, a reader could understandably mistake the "belief certainty" levels in the table as %'s of subjects who agreed with one or another concrete proposition. To find an explanation of what the "0-100" values are actually measurements of, one has to read the Climatic Change paper-- or actually, the on-line supplementary information for the Climatic Change paper.

Weirdly, the authors simply don't report how the information affected the proportion of subjects who said they believe in climate change, human-caused or otherwise! If the authors have data on %s who believed in climate change before & after etc, I'm sure readers would actually be more interested in those....

But based on the "belief certainty" values in the table, it looks to me like the members of this particular sample, were, on average, somewhere between ambivalent and moderately certain about these propositions before they got the "97% consensus msg."

After, they got the message, I'd say they were, on average,  ... somewhere between ambivalent and moderately certain about these propositions.

From "75.19" to "76.88" in "belief certainty": yes, that's "increased support for policy action," but it sure doesn't look like anything that would justify continuing to spend milions & millions of dollars on a social marketing campaign that has been more or less continuously in gear for over a decade with nothing but the partisan branding of climate science to show for it.

The authors repeatedly stress that the results are "statistically significant."

But that's definitely not a thing significant enough to warrant stressing.

Knowing that the difference between something and zero is "statistically significant" doesn't tell you whether what's being measured is of any practical consequence.  

Indeed, w/ N = 1,104, even quantities that differ from zero by only a very small amount will be "statistically significant."

The question is, What can we infer from the results, practically speaking? 

A collection of regression coefficients in a path diagram can't help anyone figure that out.

Maybe there's more to say about the practical magnitude of the effects, but unfortunately the researchers don't say it.

For sure they don't say anything that would enable a reader to assess whether the "97% message" had a meaningful impact on political polarization.

They say this: 

While the model “controls” for the effect of political party, we also explicitly tested an alternative model specification that included an interaction-effect between the consensus-treatments and political party identification. Because the interaction term did not significantly improve model fit (nor change the significance of the coefficients), it was not represented in the final model (to preserve parsimony). Yet, it is important to note that the interaction itself was positive and significant (β = 3.25, SE = 0.88, t = 3.68, p < 0.001); suggesting that compared to Democrats, Republican subjects responded particularly well to the scientific consensus message.

This is perplexing....

If adding an interaction term didn't "significantly improve model fit," that implies the incremental explanatory power of treating the "97% msg" as different for Rs and Ds was not significantly different from zero. So one should view the effect as the same.

Yet the authors then say that the "interaction itself was positive and significant" and that therefore Rs should be seen as "respond[ing] particularly well" relative to Ds. By the time they get to the conclusion of the paper, the authors state that "the consensus message had a larger influence on Republican respondents," although on what --their support for policy action? belief in climate change? their perception of % of scientists who believe in climate change? -- is not specified....

Again, though, the question isn't whether the authors found a correlation the size of which was "significantly different" from zero.

It's whether the results of the experiment generated a practically meaningful result.

Once more the answer is, "Impossible to say but almost surely not."

I'll assume the Rs and Ds in the study were highly polarized "before" they got the "97% consensus msg" (if not, then the sample was definitely not a valid one for trying to model science communication dynamics in the general population). 

But because the authors don't report what the before-and-after-msg "belief certainty" means were for Rs and Ds, there's simply no way to know whether the "97% consensus msg's" "larger" impact on Rs meaningfully reduced polarization.

All we can say is that whatever it was on, the "larger" impact the msg had on Rs must still have been pretty darn small, given how remarkably unimpressive the changes were in the climate-change beliefs, risk perceptions, and policy attitudes for the sample as a whole.


The authors state that their "findings provide the strongest evidence to date that public understanding of the scientific consensus is consequential." 

If this is the strongest case that can be made for "97% consensus messaging," there should no longer be any doubt in the minds of practical people--ones making decisions about how to actually do constructive things in the real world-- that it's time to try something else.

To be against "97% consensus messaging" is not to be against promoting public engagement with scientific consensus on climate change.

It's to be against wasting time & money & hope on failed social marketing campaigns that are wholly disconnected from the best evidence we have on the sources of public conflict on this issue.




Had "comments disabled" for yesterday's post on  Session 7 of virtual "Science of Science Communication 2.0"

Was wondering why there weren't the usual 7,000+ "student" comments!

The sole purpose of this post is to announce that the comments feature for that one is now enabled.  Because that's the logical place for discussion, I'm disabling comments here.


Science of Science Communication 2.0, Session 7.1: communicating climate science part 2

It's that again! Another session -- # 7 --of virtual "Science of Science Communication 2.0"

Reading list here

Imagine you were

  1. President Obama about to make a speech to the Nation in support of your proposal for a carbon tax; 

  3. a zoning board member in Ft. Lauderdale, Florida, preparing to give a presentation at an open meeting (at which members of the public would be briefed and then allowed to give comments) defending a proposed set of guidelines on climate-impact “vulnerability reduction measures for all new construction, redevelopment and infrastructure such as additional hardening, higher floor elevations or incorporation of natural infrastructure for increased resilience”; 

  5. a climate scientist invited to give a lecture on climate change to the local chapter of the Kiwanis in Springfield, Tennessee; or 

  7. a “communications consultant” hired by a billionaire, to create a television advertisement, to be run during the Superbowl, that will promote constructive public engagement with the science on and issues posed by climate change.

Would the CRED manual be useful to you? Would the studies conducted by Feygina, et al., Meyers et al., or Kahan et al. be?  How would you advise any one of these actors to proceed?


Some other places to to find discussion

Couple of posts elsewhere worth checkiout out today.

1st is Tamar Wilner's great "response paper" for Science of Science Communication course session 6. She asks whether the evidence for "97% consensus messaging" bears critical scrutingy

2d is a post by me on Washington Post Monkey Cage discussing our recently published paper on geoengineering and "two-channel science communication."

One thing that bums me a bit about the post is that they edited out material at end explaining that the experiment was a model, not a proposed "communication framing strategy," and that the value of such a study is in guiding field studies.

Also not thrilled with headline--I don't study science communication to teach people how to "change skeptics' minds"; I do studies to show how to communicate science in a manner that enables people to decide for themselves what to make of it.

Oh well...





Weekend update: Hard questions, incomplete answers, on the "disentanglement principle"

I have written a few times now about the “disentanglement principle”—that science communicators & educators must refrain from “making free, reasoning people choose between knowing what’s known by science and being who they are.”  The Measurement Problem paper uses empirical evidence to show how science educators and communicators have “disentangled” identity and knowledge on issues like evolution & climate change, and proposes a research program aimed at perfecting such techniques.

In a comment on a recent post, Asheley Landrum posed a set of penetrating and difficult questions about “disentanglement.”  I thought they warranted a separate blog, one that I hoped might, by highlighting the importance of the questions and the incompleteness of my own answers, motivate others to lend their efforts to expanding our understanding of, and ability to manage, the problem of identity-knowledge entanglement.

Asheley's comment:

I'm really interested in the idea of disentangling identity from knowledge. However, I wonder to what extent that really can be done. Take, for instance, the conflation of belief in evolution versus knowledge of evolution that you've described. Does it matter if multiple cultural identies recognize that the theory of evolution states humans evolved from earlier species of mammal if they do not accept (or believe) it to be extremely likely to be true? Is our goal as scientists (and science communicators) to make sure that people simply know what a theory is comprised of but not worry about whether the public buys it?

Also, once a topic becomes politicized, is it possible to truly disentangle that topic from people's cultural identies? I feel like new work is showing how we can potentially stop topics from becoming politicized in the first place, but once a topic becomes entangled with cultural identy, the mere mention of it may trigger motivated cognition. Is it something that will pass with time? For instance, we've seen public perception shift on a myriad of social issues (e.g. Interracial marriage, now gay marriage). Is this a result of time or a change in the narrative surrounding the topics? Does changing the narrative surrounding certain science topics change eventually change how entangles that topic is with regard to cultural identity?

My response:


Good questions. I certainly don't have complete answers.

But I'd start by sorting out 3 things.

1st, is "non-entanglement" possible?

2d, can entanglement be undone?

3d, is the goal of the science communicator/educator “belief” or “knowledge”?

1. Is non-entanglement possible?

I take this to mean, is it possible to create conditions where people don't have to choose between knowing what's known and being who they are?

Answer is, of course.

For one thing, the issue never arises for most issues -- ones for which it very well could have.

E.g., identity and knowledge were "entangled" on HPV vaccine but not the HBV vaccine.

The former—as a result of factors that were perfectly foreseeable and perfectly avoidable—traveled a path into public awareness that generated conditions, persisting to this day, that distort and disable the normally reliable faculties parents use to make informed decisions about their children’s health.

Likewise, there's no entanglement between identity and knowledge and GMO in US - - even though there is in Europe.

There's no entanglement on vaccine safety in US -- although there might well be if we don't stifle the evidence-unencumbered misrepresentations about the extent of vaccine risk perceptions and the relationship between them and cultural styles.

So the first thing is, there is nothing necessary about entanglement; it happens for reasons we can identify; and if we organize ourselves appropriately to use the science of science communication, we can certainly avoid this reason-eviscerating state of affairs.

Another pointeven when positions on risks and other facts become entangled in antagonistic cultural meanings--turning them into symbols of cultural identity--it still is possible to create conditions of science communication that free people from having to choose between knowing and being who they are!

You advert to this in raising evolution. We know from empirical evidence that it is possible to teach evolution in a manner that doesn't make religious students choose between knowing and being who they are and that when the right mode of teaching (one focusing on simply valid inference from observation), they can learn the modern synthesis just as readily as students who say they "do believe" in evolution (and who invariably don't know anything about natural selection, random mutation, and genetic variance).

We need similar pedagogical strategies for teaching evolutionary science—and able teachers and researchers are busy at work on this problem.

I think, too, we are seeing successful disentanglement strategies being used in local government to promote evidence-based climate policymaking aimed at adaptation.

We need to study these examples and learn the mechanisms they feature and how to harness and deploy them to promote knowledge.

2. Can entanglement be undone?

As I mentioned, in most cases, the entanglement problem never arises-- as in case of HBV vaccine or GMO foods.

But if entanglement occurs-- if antagonistic meanings become attached to issues turning positions on them into symbols of identity--can that condition itself be neutralized, vanquished

This is different, I think, from asking whether, in a polluted science communication environment, it is possible to "disentangle" in communicating or teaching climate science or evolution, etc.

The communication practices that make that possible are in the nature of "adaptation" strategies for getting by in a polluted science communication environment.

The question here is whether it possible to decontaminate a polluted science communication environment.

I think this is possible, certainly. I suppose, too, I could give you examples where this seems to have happened (e.g., on cigarette smoking in US).

But the truth is, we know a lot less about how risks and like facts become entangled in antagonistic meanings, and about how to “adapt” when that happens, than we do about how to clear the science communication environment of that sort of pollution once it becomes contaminated by it.

We need more information, more evidence.

But the practical lesson should be obvious: we must use all the knowledge at our disposal, and summon all the common will and attention we can, to prevent pollution of the science communication environment in the first place (a critical issue right now for childhood vaccines).

3.  Is the goal of the science communicator/educator “belief” or “knowledge”? 

Finally, you raise the issue of what the “goal” of science communication and education is—“knowledge” vs. “belief”?

My own sense is that the “knowledge”-“belief” dichotomy here reflects at least two forms of confusion

One is semantic. It’s the incoherent idea that there is some meaningful distinction between the objects of “belief” and the objects of “knowledge” and that “science” deals with the latter.

I’ve discussed this before. It’s not worth going into again, except to remark that those who think they are making an important point when they assert “it’s not a belief—it’s a fact!”need to seek guidance from the two patron saints of science’s theory of causal inference—the Rev. Thomas Bayes and Sir Karl Popper—to get some remedial instruction on how empirical proof expands our knowledge (by furnishing valid observational evidence on the basis of which we update our current beliefs about how the world works).

The other confusion is more complicated. It's certainly not a cause for embarrassment, but not grasping it is certainly a cause for concern.

The nature of the mistake (I'm still struggling, but am pretty sure at this point that this is the nub of the problem) is to believe that, as a psychological matter, it makes sense to individuate people's "beliefs" (or items of "knowledge") independently of what those people are doing.

Consider Hameed’s Pakistani Dr.  He says he doesn’t “believe in” evolution: “Allah created man! We did not descend from monkeys!”

Yet he tells you “of course” he depends on evolutionary science in his practice as an oncologist, where he uses insights from this field to screen patients for potential cancer risks. 

Of course” medical research relies on evolutionary science, too, he says—“consider stem cell research!”

If we say, “but isn’t that inconsistent—to say you ‘disbelieve’ in evolution but then make use of it in those ways as a Dr?,” he thinks we are being obtuse.

And he is right.

As Everhart & Hameed helps us see, there are two different “evolutions”: the one the Dr rejects in order to be a member of a religious community; and the one he accepts in order to be a doctor and a member of a scientific-knowledge profession.

The idea that there is a contradiction rests on a silly model that thinks individuals’ “beliefs” (or what is “known” by them) can be defined solely with reference to states of affairs or bodies of evidence in the world.

In the mind, “beliefs” are intentional states--often compound ones, consisting of assent to various factual propositions but also pro- or con- affective stances, and related propensities to action--that are yoked to role-specific actions

As a psychological matter, then, what people “believe” or “know” cannot a be divorced from what use they make of the same.

Being a member of a religious community and being as a member of the medical profession are integrated elements of the Pakistani Dr's identity. 

As a result, there’s no contradiction between the Pakistani Dr. saying he “disbelieves” in evolution when he is “at home” (or at the Mosque), where the set of intentional states that signifies allows him to be the former, and that he “believes in” it when he is “at work,” where the set of intentional states that signifies allows him to be a member of a science-informed profession.  

He knows that the evolution he accepts and the one he rejects both refer to the same account of the natural history of human beings that originates in work of Darwin; but the one he accepts and the one he rejects are "completely different things" b/c connected to completely different things that he does.  

It's confusing, I agree, but he's not the one who is confused-- we are if we can't get grasp the point knowing that can't be disconnected, psychologically, from knowing how!

Still, the Pakistani Dr is is lucky to live a life in which the two identities that harbor these competing beliefs have no reason to quarrel.

For members of certain religious communities in the US–and as Hameed notes, for more and more Islamic scientists and scientists in training in Europe—that's not so.

There is a social conflict, one foisted on them by illiberal cultural status competition, that makes it impossible to use their reason to be both members of cultural communities and science-trained professionals at the same time.

So what should the goal of the science communicator and teacher be?

It should be to make it possible for people to recognize and give effect to scientific knowledge in order to do the things the doing of which require such knowledge: like being scientists; like being successful members of other professions, including, say, agriculture, that depend on knowing what science knows; like being a good parent; like being a member of a self-governing community, the well-being of which turns on it making science-informed policy choices; and like being curious, reflective people who simply enjoy the awe and pleasure of being able to participate in comprehending the astonishing insights into the mysteries of nature that our species has gained by using the signature methods of scientific inquiry.

If a science teacher or communicator thinks that it his or her job “to “get people to say they ‘believe in’ ” evolution or climate change independently of enabling them to do things that depend on making use of the best available evidence, then he or she is making a mistake.

If that a science educator thinks that he or she is doing a good job because people say they “believe in” those things even though they couldn’t pass a high-school biology test on natural selection, and think that CO2 is poisonous to plants, then he or she is incompetent.

And if he or she is trying to get people who use scientific knowledge related to climate change or evolution or anything else to say they “believe in” it when the only purpose that would serve is to force them to denigrate who they are, then he or she has become a source, witting or unwitting, of the science communication pollution that entangles identity and knowledge and that disables free and reasoning democratic citizens from making use of all the scientific knowledge at their disposal.


"Measurement Problem" published but still unsolved

Published version of this paper is now out....


But I don't expect the mystery of the Pakistani Dr. and the Kentucky Farmer to be solved anytime soon....




On becoming part of a polluted science communication environment while studying it....

From a correspondent, cc'ing me

Dear National Geographic Forum,
I am an engineer who, in addition to engineering-related courses, also studied geology, geophysics and even a little astronomy at the undergraduate and graduate level. In short, a big fan of science and rational thought, especialy applied science like engineering.
I firmly believe in climate change but find that the claim that it is "human-made" is total rubbish.  
Rather I think the human-made claim is driven by "tribalism", just like Professor Dan Kahan of Yale Law School ascribes to the "barber in a rural town in South Carolina". (And seriously, good he be any more elitist and patronizing? North vs. South, City Mouse vs. Country Mouse, Perfesser of Law vs. Barber, etc.)
In fact, the tribal forces at work on researchers and politicians are much more pronounced. 
It's not just about losing customers, it's about fame, glory, popularity and - most important - money.  
Think Oscars, think Nobel Prizes, think tapping into the hundreds of millions of dollars (billions?) out there for the taking.
All you have to do is run the same flawed computer programs, fiddle with the data when necessary, and confirm, affirm, re-affirm The Consensus.
And, if that isn't enough enticement, you also get to adopt a holier-than-thou attitude when talking about "Skeptics".  I mean, it's no accident that your article states "How to convert the skeptics?"
Maybe you should take a look in the mirror.
When you liken the more than half of Americans who don't believe the Earth is warming because humans are burning fossil fuels to "loopy... flat-Earthers" you are reinforcing tribalism.
My response

Thanks, ***. 

I'm going to put aside "who is right" on climate change and also how the sorts of influences I study bear on the production of climate science or any other form of science. One can't reliably draw any inferences from studies of how dynamics like identity-protective cognition affect public opinion, on the one hand, to how the same dynamics affect the expert judgments of scientists or any other group of professionals (like judges, say!), on the other.  If one wants to figure out if the conclusions of expert decisionmakers are being biased by identity-protective cogntion or comparable dynamics, then one has to perform valid studies on samples of the experts in question as they apply their professional judgment to the types of problems for which it is suited.

But I agree with the science-communication points you are raising here.

I don't think it is useful at all to characterize as "anti-science" the 50% of US general population who, using exactly the same forms of reasoning as those who conclude that best evidence supports belief in AGW, conclude that the best evidence doesn't support it. 

On the contrary, I think the dynamics that generate these sorts of characterizations are exactly what prevent culturally diverse citizens from converging, as they usually do, on what science knows. 

Some papers that address these points; happy to receive the benefit of any comments (including critical ones) you have on them:

Kahan, D.M. What is the "Science of Science communication"? J. Sci. Comm. (in press). 

Kahan D.M. Climate-Science Communication and the Measurement Problem. Advances in Political Psychology (in press). 

Kahan, D. Fixing the Communications Failure. Nature 463, 296-297 (2010).

I often find my and my collaborators' research cited -- by both "left" & "right" (those are crude ways to characterize the relevant cultural groups, but they are good enough here) -- to "explain" why the "other side" is dogmatic, anti-science, stupid, etc.   

That sort of misinterpretation of our findings is part of exactly the phenomenon we are studying: the forces that drive people to misconstrue empirical evidence in patterns congenial to their cultural outlooks.

Indeed, for a study of how people misconstrue evidence relating to the open-mindedness & critical reasoning capacities of those who disagree w/ them on contested science issues, take a look at Kahan, D.M. Ideology, Motivated Reasoning, and Cognitive Reflection, Judgment and Decision Making 8, 407-424 (2013).  The most demoralizing thing is that this tendency is most pronounced in individuals with highest proficiency in critical reasoning.... 

Makes me wonder sometimes whether there's any point in trying to use empirical evidence to fix this problem.

But it takes only about 15 seconds to conclude that of course that would be the wrong conclusion to draw.

Because for one thing, any scholar who gets the benefit of being supported by a liberal democratic society to do scientific research would have to be a moral cretin not to recognize that he or she owes that society's members whatever he or she can contribute to protecting their science communication environment from the sort of toxins that deprive liberal democratic citizens of the benefits of all the scientific knowledge their way of life makes possible.

There is one more thing I want to be sure I express my agreement with:  I don't doubt for a second that I myself, in the course of trying to address these matters, will blunder, either as a result of being subject to the same dynamics I'm studying or to simple failings in judgment or powers of expression.  And as a result, I'll end up conveying, contrary to my own intentions and ambitions, the very sort of partisan meanings that I believe must be purged from the science communication environment.

I don't resent being told when that happens; I am chastened, but grateful. 

Take care. 



It's in people's self-interest to form beliefs that connect rather than estrange them from those whose good opinion they depend on (economically, emotionally, and otherwise).  As a result, we should expect individuals' cultural outlooks to have a very substantial impact on their climate change risk perceptions.

At the same time, the beliefs that the typical member of the public forms about climate change will likely have an impact on how she gets along with people she interacts with in her daily life. A Hierarchical Individualist in Oklahoma City who proclaims that he thinks that climate change is a serious and real risk might well be shunned by his coworkers at a local oil refinery; the same might be true for an Egalitarian Communitarian English professor in New York City who reveals to colleagues that she thinks that “scientific consensus” on climate change is a “hoax.” They can both misrepresent their positions, of course, but only at the cost of having to endure the anxiety of living a lie, not to mention the risk that they’ll slip up and reveal their true convictions. Given how much they depend on others for support—material and emotional—and how little impact their beliefs have on what society does to protect the phys-ical environment, they are better off when they form perceptions of climate change risk that minimize this danger of community estrangement.

In contrast, what an ordinary individual believes and says about climate change can have a huge impact on her interactions with her peers. If a professor on the faculty of a liberal university in Cambridge Massachusetts starts saying "cliamte change is ridiculous," he or she can count on being ostracized and vilified by others in the academic community. If the barber in some town in South Carolina's 4th congressional district insists to his  friends & neighbors that they really should believe the NAS on climate change, he will probably find himself twiddling his thumbs rather than cutting hair.


* * *

At the same time, the beliefs that the typical member of the public forms about climate change will likely have an impact on how she gets along with people she interacts with in her daily life. A Hierarchical Individualist in Oklahoma City who proclaims that he thinks that climate change is a serious and real risk might well be shunned by his coworkers at a local oil refinery; the same might be true for an Egalitarian Communitarian English professor in New York City who reveals to colleagues that she thinks that “scientific consensus” on climate change is a “hoax.” They can both misrepresent their positions, of course, but only at the cost of having to endure the anxiety of living a lie, not to mention the risk that they’ll slip up and reveal their true convictions. Given how much they depend on others for support—material and emotional—and how little impact their beliefs have on what society does to protect the phys-ical environment, they are better off when they form perceptions of climate change risk that minimize this danger of community estrangement.



Science of Science Communication 2.0, Session 6.1: Communicating climate science, part 1

It's time for session 6 of virtual "Science of Science Communication 2.0" (time for real-space version in about 4 hrs)! Reading list here



"Let's shame them!": part and parcel of the dangerous seat-of-the-pants, evidence-free style of risk communication we are using to protect universal vaccination in US

A thoughtful correspondent asked me what I thought of proposals to "shame" parents who don't vaccinate their children.  I'm against doing that. Actually, I'm not opposed to "shaming" when it makes sense; but I am opposed to doing anything in public policy that disregards the best evidence we have on the challenges we face and the best strategies for combatting them. Here is what I had to say about why shaming parents who don't vaccinate should be viewed as falling into that category:

I myself don't see any value in shaming here.

The conflict-entrepreneur, anti-vax organizers deserve ridicule and are awful people etc. But denouncing or shaming them actually only gives them exactly what they want -- more attention, which in turn does make more members of the public agitated and confused. 

This is known as the “rope-a-dope” strategy. Many vaccine advocates are falling for it big time and are doing more harm than good by falsely overstating the impact of the small fringe of society that is anti-vaccine.

In addition, shaming individual parents risks chilling anxious individuals who aren't militant or political but just confused from trying to get answers to their questions from their drs or neighbors etc. 

No one could think that’s good for public health. Thoughtful and reflective people can actually help those parents see that vaccination makes sense for their kids and for society as a whole--but only if those parents seek out their counsel.

Finally, shaming risks undermining the social norms most worthy of protection here.

One is the general confidence that parents indisputably have (as manifested in maintenance of the public-health goal of 90%+ vaccination rates for over a decade) in vaccine safety. The main source of information that people use to assess risk is the attitude of other ordinary people as evinced by their behavior.

What we definitely don't want, then, is to give people a false impression that fear of and resistance to vaccines are widespread or growing. The incessantly repeated, demonstrably false assertion that vaccination rates are falling & exemptions rising in the US does exactly that: it causes people to misperceive how much confidence US parents have in vaccination -- to misperceive how high our vaccination rates are & have been for well over a decade.

The other is reciprocal cooperation.  People contribute to public goods when they perceive others are -- but don't when they perceive others aren't, in which case contributing makes one feel like a sucker.  Herd immunity is a public good. In fact, studies show that giving people the impression that others are refusing to vaccinate diminishes their own intention to vaccinate.

I'd worry that the spectacle of orchestrated shaming -- b/c the premise for it is falling vaccine rates, etc. -- could reinforce these norm-eroding effects. 

Instead, we should want parents and the public generally to know, as Moms Who Vax wisely emphasize, that “the vast, vast majority of” parents do recognize that vaccines are critical for their kids welfare.  

Those parents have better things to do than march around asserting the obvious, so it is easy to lose the benefit that their behavior and confidence can contribute to the norms that promote universal vaccination.  

Let's follow the lead of MWX and and raise the profile of the behavior and attitude of those ordinary parents.

We should also take the money and attention that would otherwise be devoted to pointless and likely self-defeating shaming campaigns (ones coordinated by commercial marketing firms poised to carry out this questionable strategy) and direct it to research into developing screening instruments that can help identify vaccine-hesitant parents and targeted risk counseling for them.

The scientists doing this research aren't nearly as loud, nearly as self-promoting, as the advocates who are overstating anxiety about vaccines and the need for unresponsive policies like "shaming campaigns."

So like MWV, we should be trying to remedy this inattention by hearalding what these researchers are up to, and helping those dedicated to perfecting our universal vaccination regime to make sure that these researchers are adequately supported in their efforts.


Turbulence and shifting gusts of hot air: the forecast for perceptions of "scientific consensus" in response to NAS geoengineering reports

They aren’t the first National Academy of Sciences Reports to call for stepping up research on geoengineering, but the ones the Academy issued Tuesday are definitely raising both the volume and intensity of this recommendation.

In response, I predict an interesting counter-reaction by many of the advocacy groups involved in promoting graeater public engagement with climate science. 

A prominent if not dominant stance among such groups, I’m guessing, will be to dismiss geoengineering as impractical, dangerous, futile, etc.

And impolitic as well: triggering an outcome referred to as "moral hazard" (an inapt label, given the established meaning of this term in economics), talk of geoengineering, it is asserted, will lull people into believing climate change can be met w/o significant changes in their lifestyle, thereby dissipating the groundswell of popular support (?!) for restrictions on use of carbon-emitting greenhouse gasses.

I’m guessing that we'll see this reaction, first, because that’s already how many climate-policy advocates have reacted whenever anyone mentions geoengineering.

And I’m guessing this is what we'll see, second, b/c such a reaction would be in keeping with dynamics of cultural cognition generally and with studies of geoengineering and perceptions of “scientific consensus” in particular.

Just the day before yesterday (we take seriously our commitment to our 14 billion regular blog subscribers to be as topical as possible!), CCP’s study "Geoengineering and Climate Change Polarization: Testing a Two-Channel Model of Science Communication" was published in the Annals of the American Academy of Political and Social Science.

It reports the results of a two-nation—US and England—experiment that found that subjects who learned of scientist’ call for research into geoengineering were in fact less cultural polarized in their subsequent assessment of the strength of the evidence of human-caused climate change than were subjects who first learned of scientists’ ‘call for more carbon emission limits. 

The latter were in fact more polarized than subjects in a control group, who considered the evidence of human-caused climate change without any information on carbon-emission limit or geoengineering-research proposals.

This finding was consistent with the hypothesis that learning that geoengineering, a pro-technology response, was being given serious consideration would reduce the defensive biases of citizens culturally predisposed to discount evidence of human-caused climate change insofar as accepting it implies limits on markets, commerce, and industry—activities that individuals with this cultural orientation value, symbolically as well as materially.

Contrary to the often-asserted "moral hazard" claim, telling people about geoengineering research did not reduce concern about climate change risks. 

On the contrary, the subjects who learned about the proposal for such research were more concerned, presumably because the ones most prone to skepticism reacted much more open-mindedly to evidence of global warming.

The second study that predicts that many climate-change policy advocates will react dismissively to the NAS (and Royal Society) recommendations to research geoengineering is the CCP study on cultural cognition of scientific consensus.

That one found that individuals tend to credit or discredit representations of scientific consensus on risk and related facts in a selective pattern that reflects their cultural worldviews. 

Egalitarian, communitarian individuals credit the expertise of scientists who assert that climate change and nuclear power pose huge environmental risks and dismiss the expertise of scientists—ones with exactly the same credentials—who assert otherwise.

The pattern is reversed in hierarchic, individualistic subjects.

If that's how people process information about "scientific consensus" in the real world, than people with these opposing outlooks will end up forming opposingly skewed understandings of what scientific consensus is on these and other issues. And in fact, that’s what surveys show to be the case.

So here we can expect egalitarian communitarians—who readily perceive scientific consensus in favor of human-caused climate change—to dispute that there is "really" scientific consensus in favor of investigating the contribution geoengineering can make to counteracting climate-change risks.

They’ll either dismiss the NAS and Royal Society reports or construe them as saying the opposite of what they say (that more research is indeed warranted) because the suggestion that one response to climate change is more innovation, more technology—not less of all of those things—disappoints their cultural worldview, which is exactly what motivates a good many of them to exhuberantly embrace evidence of climate change.

Geoengineering is “liposuction,” when what capitalism really needs to do is go on a “diet,” as one commentator poetically put it.

Identity-protective reasoning doesn't discriminate on the basis worldview.  

Its reason-eviscerating effects are symmetric across the ideological spectrum.  We are all vulnerable.  

And the reactions to geoengineering might help us to see that; or it might not, precisely because it's in the nature of the disease to discern its effects only in those who belong to an opposing cultural group and never in the members of one's own....

Anyway, that’s my prediction about how people will react to the new NAS reports.

Guess we'll find out.    


"What is the 'science of science communication'?" (new paper)

A short essay that tries to tie some bigger themes together...


Science of Science Communication 2.0, Session 5.1: the (mis)communication of vaccine-risk perception

It's been a while -- at least 45 mins -- since I've written about vaccine-risk perception and communication.  Well, conveniently, today's session -- #5 -- of  Science of Science Communication course ver 2.0 happens to be on this very topic.  To get the "virtual class" discussion going (real-space class is starting in 60 mins!), consider this case study, which was appended to this week's reading list:

Case Study: Vaccine Risk Communication

1. The Wakefield affair. In 1998, the medical journal the Lancet published a study by a team of researchers led by Andrew Wakefield that purported to establish a connection between the MMR vaccine and autism. Although the study was attacked almost immediately and ultimately was retracted by the journal, the Wakefield paper stoked considerable public anxiety in the U.K., where vaccination rates declined and the incidence of various childhood diseases increased.

2. U.S. Vaccine Risk Anxiety. The U.S. has experienced several pertussis or whooping cough epidemics in recent years as well as recurrent outbreaks of measles, a disease that was deemed eliminated in the U.S. in 2000.  These developments are widely attributed to the growing influence of anti-vaccination groups, high-profile members of which include political figures like Robert Kennedy, Jr. and the Hollywood celebrity Jenny McCarthy, which continue to disseminate the Wakefield study, supplemented with a wide variety of other materials that misrepresent vaccine safety.

Chronicling the misinformation efforts of the activists, public health professionals and journalists warn of a “growing crisis of public confidence” in childhood vaccines. More and more “mainstream parents” are availing themselves of permissive “moral” and “religious” exemptions to universal vaccination, these concerned observers report.  The resulting “erosion in vaccination rates,” a physician who has assumed a high-profile role as an opponent of anti-vaccine activists, national vaccination rates are at risk of dipping below the threshold necessary to preserve herd immunity.

3. The PUAA plan. “Progressives United Against Anti-Science” (PUAA) is a public interest group.  Combatting the anti-vaccine movement is one of its three missions. The other two are correcting the misinformation of climate change deniers and challenging efforts to add the teaching of “creation science” or “intelligent design” to public school curricula.

PUAA has formulated a two-prong plan to counteract the spread of vaccine refusal in the U.S. The first is a multi-million “social marketing campaign” consisting of high-exposure public service announcements, which would variously rebut misinformation about the risks posed by vaccines and seek to excite disapprobation toward parents who decline vaccination for endangering the public health generally.  The second prong of the PUAA plan would involve the promotion of state referenda to repeal “non-medical” exemptions to universal vaccination policies.

To fund its plan, PUAA is seeking a $500 million grant from the General Welfare Foundation (GWF). GWF is among the largest philanthropic NGOs in the U.S.  Promotion of public health is one of its primary interests.

PUAA  has also reached out to both the CDC and the American Medical Association. Because of the CDC’s and AMA’s important institutional roles in the public health establishment, PUAA believes, with good reason, that their communication of support for its plan would significantly increase the prospect of it obtaining funding from GWF.

4.  Issues. Should GWF fund the PUAA plan?  Should the CDC and AMA convey their approval?  Is there enough information to answer these questions?  If not, what additional information would be useful?


Let it be? Measuring partisan reactions to existing mandatory vaccination laws

In the last week or so, I’ve done somewhere between 2 and 406 blog posts on vaccine risk perceptions (I am indeed bored beyond description; I feel obliged to reciprocate, though, the admirable efforts of others who are trying to shield public discourse from the harm associated with fact-free assertions in this area).

The upshot is that, contrary to the empirically uniformed and reckless blathering of “news” reporters and commentators (not all reporters or commentators are engaged in this behavior!), there is no meaningful public conflict over vaccine safety.

Not only have U.S. vaccination rates held steady at over 90%--the public health target—for all recommended childhood immunizations for over a decade.

But there is also overwhelming consensus in the general population, and within every recognizable political and cultural subsegment of it, that vaccines are safe and make a vital contribution to public health.

But these are characterizations of public risk perceptions

Someone could—a commentator responding to one of my earlier posts did—reasonably ask about whether consensus on vaccine safety translates into consensus in favor of mandatory vaccination laws.

All U.S. states have such laws, requiring vaccination for mumps, measles, and rubella, along with various other childhood diseases, as a condition of school enrollment.  All have so-called “medical exemptions,” for children who have a condition that would make vaccination unsafe, and most “religious” and some “moral” exemptions as well.

Can we say that the same state of consensus exists on this public health regulatory regime?

I’ll show you some data in a sec.

But because this post exceeds what the 14 billion regular readers of this blog know is my usually strictly enforced limit of 250 words, I'll start with this helpful and succinct summary of my own interpretation of them:

1.  Yes, the same consensus supports the current state of the law on mandatory vaccination in the U.S.

2.  However, pursuing legislation to change the status quo—either by eliminating religious or moral exemptions or by eliminating mandatory vaccination laws —risks polarizing the public along familiar political/cultural lines.

3.  Launching childhood vaccines into the reason-eviscerating maelstrom of cultural status conflict that now characterizes issues like climate change, gun control, and the HPV vaccine would itself put this important aspect of our public health system in serious jeopardy. Accordingly, anyone who is considering initiating a campaign to change existing mandatory vaccination laws should (if they care about public health as opposed to making money by being employed to organize such a campaign; marketing and like consulting firms have a huge conflict of interest here) very carefully weigh the risk of that outcome against whatever benefits they might be hoping for in pursuing this course. 

Okay. Here is the evidence.

1. Members of the nationally representative sample that participated in the CCP Vaccine Risk Perceptions and Ad Hoc Risk Communication study were asked what they thought of mandatory vaccination policies.

They responded to a series of questions, which are described in full in the Report,, after first being supplied information (also described there) that was materially identical to the information I supplied above about how those policies work and about the varying forms of exemptions that states permit.  The questions were varied randomly in order.

By an overwhelming margin, the survey participants indicated that they favor existing laws

Specifically, 75% (± 5% at a 0.95 level of confidence) indicated agreed that they “support leaving existing laws on childhood vaccinations as they are.” 

What’s more, this was by far the dominant response across political lines:

The responses to this "let it be" item reflect exactly the same pattern that characterizes the general public’s responses to the study’s vaccine risk-perception items.

Indeed, I myself do not see the response to this item as measuring anything different from what the risk-benefit items measure.

Known as the “affect heuristic,” there is a strong tendency of people to form overall pro- or con- attitudes toward putative risk sources.  Rather than a consequence of their assessment of evidence about those putative risks, their affective orientations are likely to shape how they interpret evidence and form beliefs (Slovic, Peters, Finucane & MacGregor 2005; Loewenstein, Weber, Hsee & Welch 2001).

One can ask them different questions and elicit responses that reflect people’s affective orientations toward one or another risk.

But that’s really all that one is doing with any of these questions: eliciting a generic pro-con attitude.  It is in fact a mistake—one that non-scholarly opinion pollsters invite all the time to get attention or to try to manipulate public impressions of the public’s view on one or another policy issue—to try to take the wording of particular items at face value or to purport to draw inferences from one or another as opposed to all the items considered as a group.

The reactions of members of the public to childhood vaccines displays all the signatures of the affect heuristic.

Moreover, their affective orientation happens to be very positive in the vast bulk of the U.S. population.  The CCP Report estimated that approximately 80% of the population shares it.

Like the risk-benefit questions generally, the CCP study "let it be" item on existing mandatory vaccine laws elicited a positive response of around 80%.

Like the risk-benefit items, there was not much in the way of systematic variance in the "let it be" item—that is, the reasons why somewhere around 20% or 25% of the population didn’t support existing laws did not admit of meaningful explanation by individual demographic or cultural or political characteristics.

Maybe these are the same 20% or so of the population who indicated that “space aliens” or “time travelers” were involved in the disappearance of Malaysian Airlines flight 370 last summer.  No idea.

2.  There is an important “however,” however.

Study participants were also asked to consider items relating to specific proposals to alter existing mandatory vaccination laws.

Their responses to these did not evince support consensus for change of any sort.  Indeed, it revealed the striking absence of any particular consensus:

What's more, variance in the participants’ response did reflect differences in the participants’ political outlooks.  Consider this Figure, which uses a multivariate model to estimate the impact of partisan differences, including identifying as a member of the Tea Party, on the responses to the reform items:

The figure illustrates how much more or less an average "liberal Democrat," "Conservative Republican, non--Tea Party member, or  "Conservative Republican, Tea Party member" is to agree with the indicated reform than is the "average" member of the population--and hence how likely each of the former prototypical partisans is to disagree with each of the others.

These differences are modest in relation to those, say, on climate change.  But they aren’t trivial.

Now what to make of this?

Well, if you are thinking there’s some inconsistency between the participants’ responses to these “change the status quo” items and their responses to the “let it be” item, I agree!

My view is that the “change the status quo” items are not measuring the same thing as the "let it be” item. 

Psychometrically speaking, "change the status quo" items don’t “scale” with the “let it be” item or the general battery of risk-benefit items. That’s is, they don’t display the sort of covariance that one would expect if the items were measures of a common latent or unobserved disposition.

It makes more sense to view the "change the status quo" iems as measuring (in a noisy and attenuated form, particularly in relation, to say, climate change) the general attitudes that subjects of varying political outlooks have toward governmental regulations generally.

My view is that most people generally just don’t give much thought to vaccine laws, which (with the exception of the HPV vaccine; I’ll come back to that) have not been a matter of political contestation in American life.

So if one asks members of the public what they think of universal vaccination laws, they express the same warm fuzzy feeling of contentment and gratitude that characterizes their views toward childhood vaccines generally.  These are the sensibilities, I'm confident, that for over a decade in US has lead 90%+ of parents to get all recommended childhood vaccinations for their kids.

Survey questions about changing those law, starts to trigger affective resonances that relate to peoples’ cultural identities.  Like bad survey questions, those questions aren't measuring what people in society are talking about; but they are measuring something: who they are, culturally or politically speaking.

3.  That's an outcome that ought to cause a sense of tremendous apprehension in anyone who actually values the contribution that childhood vaccines make to public health in this country.

The entanglement of issues of risk with antagonistic cultural meanings is precisely what drives polarization on issues like gun control and climate change, where people’s positions are understood to be badges of membership in and loyalty to opposing groups (Kahan 2015, 2012).

This was exactly the dynamic that generated polarization over the HPV vaccine, the only universally recommended vaccine that isn’t part of the schedule of mandatory, school-enrollment vaccinations across the U.S. states (Kahan et al. 2010).

I’ve written extensively, in this blog and elsewhere (Kahan 2013), about the sad career of the HPV vaccine.

But the basic point is that the HPV vaccine suffered this fate b/c its manufacture, Merck, decided to initiate a controversy-inviting nationwide legislative campaign to add the vaccine to the schedule of required vaccinations that states make a condition of school enrollment.

The company did so through what was initially a covert lobbying campaign that featured Governor “Oops” among others—the disclosure of which amplified the controversy the manufacturer was hoping to sidestep when it thrust the vaccine into the political process.

Merck didn’t have to do this. In the normal course, public health administrators, who are largely insulated from politics, would have almost certainly added the vaccine to their states’ requirements, as they had just finished doing for the HBV (hepatitis-b) vaccine, another STD immunization that was made mandatory for adolescents and then infants.

But the manufacture didn’t want to wait, because in extra time it would have taken to get such approval for a boys & girls vaccine added to the state mandatory lists by administrative action, a competitor, GlaxoSmithKline, would have obtained approval for a rival HPV vaccine and been able to compete for lucrative contracts with state school systems.

The risk that launching the HPV vaccine into the political process would disrupt people's ability to assess the risks and benefits of it was clear at the outset.

But Merck (for pefectly predictable, understandable reasons) decided to take a gamble, motivated by its desire to achieve a decisive commercial advantage in marketing the vaccine.

The company lost. 

We all did.

Should we take a similar gamble by taking action that would place childhood vaccinations into the cross-hairs of partisan politics? 

The CCP Report, which reported data similar to what I’ve just presented, discusses the considerations.  I don’t see any point trying to reformulate the conclusion stated there:

In striking contrast to responses to the other items in the survey, the ones soliciting participants’ positions on proposals to restrict non-medical exemptions were characterized by disagreement. Not only did these items tend to divide the respondents. They divided them on political and cultural lines....

[T]hese results supply reason for circumspection on the issue of exemptions. The power of these items to divide groups already conspicuously arrayed against each other on contested science issues raises the possibility that real-world proposals to restrict universal immunization exemptions could do the same. The study’s experimental component, which found that exposure to the “anti-science” op-ed intensified these divisions, reinforces this concern....

Anyone who dismisses the existence or seriousness of unfounded fears of childhood vaccines would be behaving foolishly. Skilled journalists and others have vividly documented enclaves of concerted resistance to universal immunization programs. Experienced practitioners furnish credible reports of higher numbers of parents seeking counsel and assurance of vaccine safety. And valid measures of vaccination coverage and childhood disease outbreaks confirm that the incidence of such outbreaks is higher in the enclaves in which vaccine coverage falls dangerously short of the high rates of vaccination prevailing at the national level (Atwell et al. 2013; Glanz et al. 2013; Omer et al. 2008).

At the same time, only someone insufficiently attuned to the insights and methods of the science of science communication would infer that this threat to public health warrants a large-scale, sweeping “education” or “marketing” campaign aimed at parents generally or at the public at large. The potentially negative consequences of such a campaign would not be limited to the waste of furnishing assurances of safety to large numbers of people who are in no need of it. High-profile, emphatic assurances of safety themselves tend to generate concern. A broad scale and indiscriminant campaign to communicate vaccine safety—particularly if understood to be motivated by a general decline in vaccination rates—could also furnish a cue that cooperation with universal immunizations programs is low, potentially undermining reciprocal motivations to contribute to the public good of herd immunity. Lastly, such a campaign would create an advocacy climate ripe for the introduction of cultural partisanship and recrimination of the sort known to disable citizens’ capacity to recognize valid decision-relevant science generally .....

The right response to dynamics productive of excess concern over risk is empirically informed risk communication strategiestailored to those specific dynamics. Relevant dynamics in this setting include not only those that motivate enclaves of resistance to universal immunization but also those that figure in the concerns of individual parents seeking counsel, as they ought to, from their families’ pediatricians. Risk communication strategies specifically responsive to those dynamics should be formulated—and they should be tested, both in the course of their development and in their administration, so that those engaged in carrying them out can be confident that they are taking steps that are likely to work and can calibrate their approach as they learn more (Sadaf et al. 2013; Opel et al. 2012).

Again, preliminary research of this sort has commended. Perfection of behavioral-prediction profiles of the sort featured in Opel et al. (2011a, 2011b, 2013b) would not only enable researchers to extend understanding of the sources and consequences of genuine vaccine hesitancy but also to test focused risk-communication strategies on appropriate message recipients.  If made sufficiently precise, screening protocols of this sort would also enable practitioners to accurately identify parents in need of counseling public health officials to identify regions where the extent of hesitancy warrants intervention.

The public health establishment should exercise leadership to make health professionals and other concerned individuals and groups appreciate the distinction between targeted strategies of this sort and the ad hoc forms of risk communication that were the focus of this study.  They should help such groups understand in addition that support for the former does not justify either encouragement or tolerance of the latter.

But anyway, you've got the data now.  Draw your own inferences -- from them, and not from the feral risk communication system that we rely on in this country to the detriment of our public health ....


Cultural Cognition Project Lab. Vaccine Risk Perceptions and Ad Hoc Risk Communication: An Emprical Analysis. CCP Risk Studies Report No. 17

Kahan, D. Why we are poles apart on climate change. Nature 488, 255 (2012).

Kahan, D., Braman, D., Cohen, G., Gastil, J. & Slovic, P. Who fears the HPV vaccine, who doesn’t, and why? An experimental study of the mechanisms of cultural cognition. Law Human Behav 34, 501-516 (2010).

Kahan, D.M. A risky science communication environment for vaccines. Science 342, 53-54 (2013).

Kahan, D.M. Climate-Science Communication and the Measurement Problem. Advances in Political Psychology 3 (2015).

Loewenstein, G.F., Weber, E.U., Hsee, C.K. & Welch, N. Risk as feelings. Psychological Bulletin 127, 267-287 (2001).

Slovic, P., Peters, E., Finucane, M.L. & MacGregor, D.G. Affect, Risk, and Decision Making. Health Psychology 24, S35-S40 (2005).






What does Christie know that the rest of us don't? My guess is nothing (or even less that that actually)

Doing his part to increase the quality of the public debate over the public's non-debate over vaccine safety, NJ Gov'r  Chris Christie delivered a gift to empirically unencumbered pundits by indicating his support (momentarily, at least) for "parental choice" on childhood immunizations.  

News stories the next day were filled with authoritative-sounding insight on what Christie's stance tells us about partisan divisions on universal vaccination.  Most explained  that Christie was trying to "appease" the Republican Party's Tea Party wing.

But there is another possibility: Christie was just making a fool of himself.

Why do I say that?

Well, to start, there is tremendous public support for universal vaccination across all demographic, cultural, religious and other lines in the U.S.

Yes, there are some people who are "anti-vax."  They are outliers in all of the groups that play a recognizable role in contested political life in the U.S.

The media is filled with stories about "growing parental" resentment and "plummeting vaccination" rates.  But those stories are based on the failure of fact checkers to do what they are paid to do.

True, the blogosphere is filled with (contradictory and even comically self-contradictory accounts) of how being "anti-vax" proves this or that cultural or poltical group is "anti-science." The only "polls" those are based on are the ones that fact-free commentators perform on themselves, or possibly the people they meet when they go shopping at whole foods.

But if Christie said he thinks that there should "parental choice," surely that must mean that in fact some significant fraction of the Republican party is anti-vax, right?!  Likely it's those stupid, evil, anti-science Tea Party members!  He must be trying to curry favor with them!


Or maybe he is just a bonehead.

To test these competing hypotheses, I decided to ... look at some actual evidence!

Based on data from the CCP Vaccine Risk Perceptions and Ad Hoc Risk Communication Report,
the figure illustrates the relationship between partisanship (measured with a scale that combines measures of liberal-conservative ideology and political-party identification) and the perceived benefits and risks of vaccines taking survey respondents' Tea Party membership into account.

Because only around 1% of the relatively liberal, Democratic respondents identified as "Tea Party members," I compared TP and non-TP members only among the relatively conservative, Republican members of the sample, of whom 30% identified as belonging to the TP (where does one sign up, btw? where are the meetings held? seriously!).

Well ... Eighty-four percent of the relative liberal, Democratic respondents and 78% of the conservative, Republican ones agreed that vaccine benefits outweigh their risks.  Boy, that's going to be a real wedge issue in the 2016 election, don't you think?

But wait-- the TP members!  A paltry 74% of them think vaccine benefits outweigh the risks! 

Look, in case you are tempted to try to squeeze a "culture conflict" out of the differences in how overwhelmingly pro-vaccine these groups of citizens are, here's graphic that shows the partisan breakdown on climate change, taking TP membership into account, in this same sample.

See the difference?

No? Well, then check out difference between what a polluted science communication environment and an unpolluted one looks like.

And if that doesn't work, then check out what happened when Glen Beck peed himself with excitement over the size of the difference in the science literacy scores of TP members (the same ones featured here) & the rest of the population.

So either 

(1) the brilliant and brilliantly advised Christie made a super shrewd move in appealing to those particular TP members who are out of step with 3/4 of their fellow TP members, and with the same proportion of non-TP conserv/repubs, thereby yanking the rug out from steam-rolling front-runner Jeb Bush, who is obviously being advised by rank amatures on this issue;


(2) Christie is a bonehead.

Call me a "contrarian" (someone did the other day for suggesting that it is actually useful to look at data when trying to interpret public opinion on science issues), but I pick bonehead.


What do polluted & nonpolluted science communication environments *look* like? & how about childhood vaccines?....

This is a common theme on this blog.  Maybe it's the only theme, in fact.

Risk perceptions that display the pathology of identity-protective cognition are pathological, both in being rare and in being inimical to public welfare.

We need to get that.

We  need to to learn how to distinguish risk perceptions that evince this pathology from ones that don't.

We need to use evidence-based methods to identify the dynamics that cause some risk issues, none of which is bound to become this way, to take on the characteristics of this pathology.

And we need to recognize our responsibility to use the knowlege we have of these dynamics to minimize the risk that any particular form of science will become infected with the pathology's reason-effacing characteristics.

Because if we don't do all these things, then we will experience many many avoidable instances of this pathology.  And for that, we'll have only ourselves to blame.


These data, btw, come from Climate-Science Communication and the Measurement Problem.


Science of Science Communication 2.0, Session 4.1: Trust in/of science 

I swear this was a huge coincidence but this week's session -- #4 -- in Science of Science Communication course ver 2.0 is ... trust in/of science!

The reading packet, distributed about about a week ago, had excerpts from 2009 Pew Report.

But for sure, live version of the class-- happening in few hrs -- will be focusing on 2015 version. Reason is less b/c of substance of 2015 Report (which is pretty much identical to 2009) than b/c of Pew's disappointing decision to hype the 2015 version in a manner that exploited popular misconceptions about declining status & authority of science in U.S. society.  Why that misconception exists and how various actors use it were among the major themes of the assigned readings!

But since I've now said so much about that, I'll just post some questions & open th floor to the "virtual class" participants to have their say.

But before I do, let me just note that next week the topic is -- (mis)communication of perceptions of vaccine-risk perceptions! We are nothing if not topical in this class!

  1. Do the NSF Indicators’ “public science attitude” items measure “trust” in science or of scientists?

  2. Is the Fiske/Dupree study consistent with the public opinion survey results reflected in the NSF Indicators?

  3. Is the Fiske/Dupree experiment internally valid? Externally?

  4. Did the media appropriately characterize the Fiske/Dupree sudy? If not, why not?

  5. Does Gauchat’s study support the inference that individuals who identify themselves as “conservative” are distrustful of science?   Is the study internally and externally valid?

  6. Did the media appropriately characterize the findings of the Gauchat study? If not, why not?

  7. Does the Jelen & Lockett study support any inferences about the relationship between religiosity and political partisanship, on the one hand, and trust in/of science? Is the study internally and externally valid?

  8. Does disbelief in evolution evince distrust in or of scientists?  Is acceptance of evolution a valid measure of “trust” in or of science? How are these last two questions related?

  9. What explains the perception that there is distrust in or of science, either in the public generally or among particular segments of it?  Does the Kahan study suggest an answer? Is that study valid, internally and externally?

  10. Are conflicts over who trusts or distrusts science something to worry about? Do they affect the quality of the science communication enviornment?


Weekend update: Pew's disappointing use of invalid survey methods on GM food risk perceptions

So here’s a follow-up on “grading of Pew's public attitudes toward science report”--& why I awarded it a “C-” in promoting informed public discussion, notwithistanding its earning an “A” in scholarly content (the data separated from the Center’s commentary, particularly the press materials it issued).

This follow-up says a bit more about the unscholarly way Pew handled public opinion on GM food risks.

Some background points:

1. It’s really easy for people to form misimpressions about “public opinion.”

Why? Because, for one thing, figuring out what “people” (who actually usually can’t usefully be analyzed w/o breaking down into groups) “think” about anything is not anything anyone can directly observe; like lots of other complicated processes, it is something we have to try to draw inferences about on the basis of things that we can observe but that are only correlates or proxies of it.

For another, none of us is in the position via our personal, causal observations to collect a valid sample of the sorts of observable correlates or proxies.  We have very limited exposure, reflecting the partiality of our own social networks and experiences, to the ways in which “the public” reveals what it thinks.  And it is in fact a feature of human psychology to overgeneralize from imperfect samples like that & make mistakes as a result.

2. One of the things many many many many people are mistaken about as a result of these difficulties is “public opinion” on GM food risks.  The media is filled with accounts of how anxious people are about GM foods.  That’s just not so: people consume them like mad (70% to 80% of the food for sale in a US supermarket contains GMOs). 

Social science researchers know this & have been engaged in really interesting investigations to explain why this is so, since clearly things could be otherwise: there are environmental risks that irrationally scare the shit out of members of the US public generally (e.g., nuclear waste disposal). Moreover, European public opinion is politically polarized on GM foods, much the way the US is on, say, climate change.  So why not here (Peters et al. 2007; Finucane, M.L. & Holup 2005; Gaskell, Bauer, Durant & Allum 1999)? Fascinating puzzle!

That isn’t to say there isn’t controversy about GM foods in American society. There is: in some sectors of science; in politics, where efforts to regulate GM foods are advanced with persistence by interest groups (organic food companies, small farmers, entrepreneurial environmental groups) & opposed with massive investments by agribusiness; and in very specialized forms of public discourse, mainly on the internet.

Indeed, the misimpression that GM foods are a matter of general public concern exists mainly among people who inhabit these domains, & is fueled both by the vulnerability of those inside them to generalize inappropriately from their own limited experience and by the echo-chamber quality of these enclaves of thought.

3.  The point of empirical public opinion research is to correct the predictable mistakes that arise from dynamics like these.

One way empirical researchers have to tried to do this in the case of GM foods is by showing that in fact members of the public have no idea what GM foods are. 

They fail miserably if you measure their knowledge of GMOs

They also say all kinds of silly things about GM foods that clearly aren’t true: e.g., that they scrupulously avoid eating them and that they believe GM foods are already heavily regulated and subject to labeling requirements (e.g., Hallman et al. 2013).

That people are answering questions in a manner that doesn’t correspond to reality shows that the survey questions themselves are invalid. They are not measuring what people in the world think—b/c people in the world (i.e., United States) aren’t thinking anything at all about GM foods; they are just eating them. 

The only things the questions are measuring—the only thing they are modeling—is how people react to being asked questions they don’t understand. 

This was a major theme, in fact, of the National Academy of Science’s recent conference on science communication & GMOs.  So was the need to try to get this information across to the public, to correct t the pervasive misimpression that GM foods are in fact a source of public division in the U.S.

So what did Pew do?  It issued survey items that serious social science researchers know are invalid and promoted the results in exactly the way that fosters the misimpression those researchers are trying to correct!

Pew asked members of their general public sample, “Do you think it is generally safe or unsafe to eat genetically modified foods?” 

Thirty-seven percent answered “generally safe,” 57% “generally UNsafe” and 6% “don’t know/Refused.”

Eighty-eight percent of the "scientist" (AAAS member) sample, in contrast, answered "generally safe."

Pew trumpeted this 51% difference, making it the major attention-grabber in their media promotional materials and Report Commentary.

This is simply pathetic. 

As an elite scholarly research operation, Pew knows that this survey item did not measure any sort of opinion that exists in the U.S. public. Pew researchers know that members of the public don't know anything about GM foods.  They know the behavior of members of the public in purchasing and consuming tons of food containing GM foods proves their is no meaningful level of concern about the risks of GM foods! 

Indeed, Pew had to know that the responses to their own survey reflected simple confusion on the part of their survey respondents.

Pew couldn't possibly have failed to recognize that because (as eagle-eye blog reader @MW pointed out) another question Pew posed to the respondents was whether “When you are food shopping, how often, if ever, do you LOOK TO SEE if the products are genetically modified?” 

Fifty-percent answered “always or sometimes.” 

This is patently ridiculous, of course, since there is nothing to see in the labels of foods in US grocery stores that indicates whether they contain GMOs. 

This is the sort of question—like the ones that show that the US public believes that there already is GM food labeling in the US, and is generally satisfied with “existing” information on them (Hallman et al. 2013)—that researchers use to show that survey items on GM food risks are not valid: these items are eliciting confusion from people who have no idea what they are being asked.

And here’s another thing: immediately before asking these two questions, Pew used an introductory prompt that stated “Scientists can change the genes in some food crops and farm animals to make them grow faster or bigger and be more resistant to bugs, weeds, and disease.”

That’s a statement that it is quite reasonable to imagine will generate a sense of fear or anxiety in survey takers.  So no surprise that if one then asks them, “Oh are you worried about this,” and “do you (wisely, of course) check to see if this weird scary thing has been done to your food?!,” people answer “oh, yes!”

Even more disturbing, the questeion immediately before that was whether people are worried about pesticides – a topic that will predictably raise risk apprehension level generally and bias upward respondents' perceptions of other putative risk sources in subsequent questions (e.g., Han, Lerner & Keltner 2007).


Bad pollsters use invalid questions on matters of public policy all the time.

They ask members of the American public whether they “support” or “oppose” this or that policy or law that it is clear most Americans have never heard of.  They then report the responses in a manner that implies that the public actually has a view on these things.

Half the respondents in a general population survey won't know-- or even have good enough luck to guess-- the answer to the multiple-choice question "how long is the term of a U.S. Senator?" Only 1/3 of them can name their congressional Representative, and only 1/4 of whom can name both of their Senators.

Are we really supposed to take seriously, then, a poll that tells us 55% of them have an opinion on the “NSA’s telephonic metadata collection policy”?!

Good social science researchers are highly critical of this sort of sensationalist misrepresentation of what is really going on in public discourse (Krosnick, Malhorta & Mittal 2014; Bishop 2005; Shuman 1998).

Pew has been appropriately critical of the use of invalid survey items in the past too, particularly when the practice is resorted by policy advocates, who routinely construct survey items to create the opinion that there is “majority support” for issues people have never heard of (Kohut 2010). 

So why, then, would Pew engage in what certainly looks like exactly this sort of practice here?

* * *

A last point.

Some very sensible correspondents on Twitter (a dreadful forum for meaningful conversation) wondered whether an item like Pew’s, while admittedly invalid as a measure of what members of the public are actually thinking now, might be a good sort of “simulation” of how they might respond if they learned more.

That’s a reasonable question, for sure.

But I think the answer is no

If a major segment of the US public were to become aware of GM foods—what they are, what the evidence is on their risks and benefits—the conditions in which they did so would be rich with informational cues and influences (the identity, e.g., of the messengers, what their peers are saying etc) of the sort that we know have a huge impact on formation of risk perceptions.

It’s just silly to think that the experience of getting telephone call from a faceless pollster asking strange questions about matters on has never considered before can be treated as giving us insight into the reactions such conditions would be likely to produce.

We could try to experimentally simulate what those conditions might be like; indeed, we could try to simulate alternative versions of them, and try to anticipate what effect they might have on opinion formation.

But the idea that the experience of a respondent in a simple opinion survey like Pew’s is a valid model of that process is absurd.  Indeed, that’s one of the things that experimental simulations of how people react to new technologies have shown us.

It's also what real-world experience teaches: just ask the interest groups who sponsored defeated referenda in states they targeted after polls showed 80% support for labeling.

But in any case, if that’s what Pew thought it was doing—simulating how people would think about GM food risks if they were to start thinking of them—they should have said so.  Then people would not have formed a misimpression about what the question was measuring.

Instead, Pew said only that they had done a survey that documents a “gap” between what members of the public think about GM food risks and scientists do.

Their survey items on GM food risks do no such thing.

And that they would claim otherwise, and reinforce rather than correct public misimpressions, is hugely disappointing.


Bishop, G.F. The illusion of public opinion : fact and artifact in American public opinion polls (Rowman & Littlefield, Lanham, MD, 2005).

Finucane, M.L. & Holup, J.L. Psychosocial and cultural factors affecting the perceived risk of genetically modified food: an overview of the literature. Soc Sci Med 60, 1603-1612 (2005). 

Gaskell, G., Bauer, M.W., Durant, J. & Allum, N.C. Worlds apart? The reception of genetically modified foods in Europe and the US. Science 285, 384-387 (1999).

Hallman, W., Cuite, C. & Morin, X. Public Perceptions of Labeling Genetically Modified Foods. Rutgers School of Environ. Sci. Working Paper 2013-2001, available at

Han, S., Lerner, J.S. & Keltner, D. Feelings and Consumer Decision Making: The Appraisal-Tendency Framework. J Consum Psychol 17, 158-168 (2007).

Kohut, A. Views on climate change: What the polls show. N.Y. Times A22 (June 13, 2010), available at

Lerner, J.S., Han, S. & Keltner, D. Feelings and Consumer Decision Making: Extending the Appraisal-Tendency Framework. J Consum Psychol 17, 181-187 (2007).

Krosnick, J.A., Malhotra, N. & Mittal, U. Public Misunderstanding of Political Facts: How Question Wording Affected Estimates of Partisan Differences in Birtherism. Public Opin Quart 78, 147-165 (2014).

Peters, H.P., Lang, J.T., Sawicka, M. & Hallman, W.K. Culture and technological innovation: Impact of institutional trust and appreciation of nature on attitudes towards food biotechnology in the USA and Germany. Int J Public Opin R 19, 191-220 (2007).

Shuman, H. Interpreting the Poll Results Better. Public Perspective 1, 87-88 (1998).


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