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« More "class discussion" | Main | Much scarier than nanotechnology, part 2 »

Why can't we all get along on climate change? (Science of Science Communication course, session 4)

This semester I'm teaching a course entitled the Science of Science Communication. I have posted general information and will be posting the reading list at regular intervals. I will also post syntheses of the readings and the (provisional, as always) impressions I have formed based on them and on class discussion. This is this fourth such synthesis. I eagerly invite others to offer their own views, particularly if they are at variance with my own, and to call attention to additional sources that can inform understanding of the particular topic in question and of the scientific study of science communication in general. 

0. What are we talking about now and why?

"Democratic self-government" consists in one or another set of procedures for translating collective preferences into public policy. Such a system presupposes that citizens’ preferences are diverse—or else there’d be no need for this elaborate mechanism for aggregating them. But such a system also presupposes that citizens have a common interest in making government decisionmaking responsive to the best available evidence on how the world works—or else there’d be no reliable link between the policies enacted and the popular preferences that democratic processes aggregate.

On the basis of this logically unassailable argument, we may take as a given that one aim of science communication is to promote the reliable apprehension of the best available evidence by democratic institutions.  This session and the next use the political conflict over climate change to motivate examination of this particular aim of science communication. This week we consider how the science of science communication has been used to understand the influences that have frustrated democratic convergence on the best available evidence on climate change.  Next week we look at how the science of science communication has been used to try to formulate strategies for counteracting these influences.

The materials read this week can be understood to present evidence relevant to four hypothesized causes for conflict over climate change: (1) the public’s ignorance of the key scientific facts; (2) the public’s unfamiliarity with scientific consensus; (3) dynamics of risk perception that result in under-estimation of affectively remote (far off, boring, abstract) risks relative to ones that generate compelling, immediate apprehension of danger; and (4) motivated reasoning rooted in the tendency of people to form and persist in perceptions of risk that predominate within cultural or similar types of affinity groups.

The empirical support for these hypotheses ranges from "less than zero" to "respectable but incomplete."  Trying to remedy this problem by combining the mechanisms they posit, however, is the least satisfying approach of all.

1. Standing the “knowledge deficit” hypothesis right side up 

 Attributing dissensus over climate change to the public’s “lack of knowledge” of the facts borders on tautology. But one way to treat this proposition as a causal claim rather than a definition is to examine whether changes in the level of public comprehension of the basic mechanisms of climate change are correlated with the level of public agreement that climate change is occurring.

By far the best (i.e., informative, scholarly) studies of “what the public knows” about climate change are two surveys performed Ann Bostrom and colleagues, the first in 1992 and the second in 2009. In the first, they found the  public’s understanding to be riddled with “a variety of misunderstandings and confusions about the causes and mechanisms of climate change”—most notably that a depletion of the ozone layer was responsible for global warming. 

Respondents in the follow-up survey did not score an “A,” either, but Bostrom et al. did find that the "2009 respondents were more familiar with a broader range of causes and potential effects of climate change.”  In particular, they were more likely to appreciate what Bostrom et al. described as the “two facts essential to understanding the climate change issue”: that “an increase in the concentration of carbon dioxide in the earth’s atmosphere” is the “primary” cause of “global warming,” and that the “single most important source of carbon dioxide in the earth’s atmosphere is the combustion of fossil fuels.”

Nevertheless the 2009 respondents were not more likely than the 1992 respondents to believe that “anthropogenic climate change is occurring” or “likely” to occur. On the contrary, the proportion convinced that climate change was unlikely to occur was higher in 2009.  These findings are in line, too, with the basic trends reported by professional polling firms, which have found that the overall proportion of the U.S. population that “believes” in climate change or views it as a serious risk has not changed in the last two decades.

click me...It might seem puzzling that there could be an increase in the proportion of the population that reports being aware that rising atmospheric CO2 levels cause global warming without there being a corresponding increase in the proportion that perceive warming is occurring or likely to occur.

But in fact there’s a perfectly logical explanation: those who believe climate change is occurring (or will) were less likely in 2009 than in 1992 to neglect to attribute climate change to rising CO2 emissions-- along with various other things.

The only causal inference one could draw from these correlations would be that the “belief” that climate change is occurring motivates people to learn the “two facts essential to understanding the climate change issue”—not vice versa.

In fact, it is more plausible to think the correlations is spurious: that is, that there is some third influence that causes people both to believe in climate change and to know (or indicate in a survey) that the cause of climate change is the release of CO2 from consumption of fossil fuels.

The Bostrom et al. study supplies a pretty strong clue about what the third variable is. In both 1992 and 2009, respondents who indicated they believed climate change was occurring were more likely to misidentify as potential “causes” of it  activities that harm the environment generally (e.g., “aerosol spray cans” and “toxic wastes”). They also were more likely to misidentify as effective climate change “abatement strategies” policies that are otherwise simply “good” for the environment (e.g., “converting to electric cars” and “recycling most consumer goods”).

This pattern suggests that what “caused” belief in climate change at both periods of time was a generic pro-environment sensibility, which also likely caused those who had it to “learn” that CO2 emissions from fossil fuels are also environmentally undesirable and therefore a cause of climate change.  Bostrom et al. report regression analyses consistent with this interpretation.

This is really solid social science-- likely the best studies we've encountered in this course. But what surprises me a lot more than Bostrom et al.’s findings is that so many thoughtful people between 1992 and 2009 were willing to bet (and still are willing to bet) that conflict over climate change is attributable to lack of public understanding.   

To be sure, it was obvious in 1992, and continues to be obvious today, that the public doesn’t have a good grasp of much of the basic science relating to climate science.  But it seems pretty obvious that it doesn’t have a good grasp of the science relating to zillions of other issues—from pasteurization of milk to administering of dental x-rays—on which there isn’t any political conflict.

Basically, if one wants to know if x & y means x -> y, then instances of x & ~y count as disconfirming evidence. Here the instances of x & ~y (lack of public understanding of science, but absence of public conflict over science-informed policy) are sufficiently obvious that I would have guessed few people would expect "lack of knowledge" to explain public controversy over climate change. 

People have to accept as known by science many more things than they could possibly understand—both as individuals making choices about how to live well and as citizens forming positions on the public good.  They can pull that off without a problem for the most part because they are experts in figuring out who the experts are.

If they aren’t converging on the best evidence on climate change, then the problem is much more likely to be some influence that is interfering with their capacity to figure out who knows what about what than their inability to understand what experts know.

2. Public controversy -> Uncertainty over scientific consensus

That’s what makes it plausible to think that the public’s unfamiliarity with scientific consensus might be the real cause of the conflict. Of course, one difficulty with this view is that it, too, must negotiate a narrow passageway between tautology (the logical line between “disagreeing about climate science” and “disagreeing about what climate scientists know” is thin) and begging the question (if the public is unfamiliar consensus here but not elsewhere, what explains that?). I think the claim can’t squeeze through. 

The public is divided over scientific consensus on climate change. But is that the cause of conflict over climate change or a consequence of it?

We read one excellent observational study (McCright, Dunlap & Xiao 2013), but simple correlations are inescapably inconclusive on this issue. Shifting variables from one side to the other of the equals sign can't break a tie between causal inferences of equal strength.

Experimental evidence is not entirely one-sided but in my view suggests that dissensus causes public uncertainty over scientific consensus rather than the other way around. Corner, Whimarsh & Xenias (2012),  e.g.,  found (with UK subjects) that individuals display confirmation bias when assessing news reports asserting or disputing scientific consensus on climate change.

In another study, CCP researchers found that subjects highly likely to identify a particular scientist is an expert on climate change only when that scientist is depicted as reaching a conclusion that matches the one in the subjects’ cultural group. If this is how people in the world process information about what “experts” believe, then we can expect them to be culturally polarized on scientific consensus—as they in fact are.

3. Bounded rationality --"believing it when you feel it” or "feeling it when you believe it"?

The idea that the public is insufficiently concerned about climate change because it relies on heuristic-driven forms of reasoning (what Kahneman calls “system 1”) to assess risk is super familiar. But it is not supported by evidence. In fact, people who are most inclined to use conscious and deliberate (“system 2”) forms of reasoning are more concerned but rather more culturally polarized over climate change.

Was the “bounded rationality” account ever truly plausible? Sure!

But it was also subject to serious doubt right from the start because from very early on it was clear that the public was divided on climate change on ideological and cultural grounds. The bounded rationality story predicts that people in general will fail to worry as much as they should about a "remote, unfelt" risk like climate change -- not that egalitarian communitarians will react with intense alarm and hierarchical individualists with indifference.

From the beginning, commentators who have advanced the bounded-rationality conjecture have forecast that more people could be expected to “believe” in climate change once they started to “feel” it. This is actually a very odd claim. Once one reflects a bit, it should be clear that one can’t actually know that what one is feeling is climate change unless one already believes in it.


  1. Alice says she knows antibiotics can treat bacterial infections because she “felt better" after the doctor prescribed them for strep throat. Bob says he knows vitamin C cures a cold because he took some and “felt” better soon thereafter.
  2. Alice says that she has “seen with my own eyes” that cigarettes kill people: her great uncle smoked 5 packs a day and died of lung cancer. Bob reports that he has “seen” with his that vaccines cause autism: his niece was diagnosed as autistic after she got inoculated for whooping cough.
  3. Alice says that she “personally” has “felt” climate change happening: Sandy destroyed her home. Bob says that he “personally” has “felt” the wrath of God against the people of the US for allowing gay marriage: Sandy destroyed his home. (Cecilia, meanwhile, reports that her house was destroyed by Sandy, too, but she is just not sure whether climate change "caused" her misfortune.)

Bob’s inferences are as good as Alice’s--which is to say, neither of them is making good ones. Neither of them felt or otherwise experienced anything that enabled him or her to identify the cause of what he or she was observing.  They had to believe on some other basis that the identified cause was responsible for what they were observing first or else they'd have no idea what was going on.

Maybe on some other basis—like a valid scientific study, say—Alice but not Bob, or vice versa, could be shown to have good grounds for crediting his or her respective attributions of causation.  But then it would be the study, and not their or anyone else’s “feeling” of something that supplies those grounds.

Realize, too, that I'm not talking about what it would be rational for Bob or Alice to believe here. I'm talking about the basis for forming plausible hypotheses about the causes of their  disagreement about climate change. Because they can't reliably "feel" the answer to the question whether human activity is causing rising sea levels, melting ice caps, increased extreme weather, etc., it is not particularly plausible to think that variance in their perceptions is what is causing them to disagree.

Not surprisingly, empirical studies do not support the “believe it when they feel it” corollary of the bounded rationality hypothesis.  In one very good study, e.g., the researchers reported that people who lived in an area that had been palpably affected by climate change were as likely to say “no” or “unsure” as “yes” when asked whether they had “personally experienced” climate change impacts.

People might start in the near future to report that they are “feeling” climate change. But if so, that will be evidence that something other than their sense perceptions convinced them that they should identify climate change as the cause of what they are experiencing.  If those who now “don’t believe” in climate change don’t change their minds, they’ll never “personally” experience or feel climate change, even if it kills them.

4. Motivated reasoning

There is strong evidence that culturally or ideologically motivated reasoning accounts for public controversy over climate change. As I’ve mentioned, cultural cognition, a species of motivated reasoning, has been shown to drive perceptions of scientific consensus and to be magnified by higher science literacy and a greater disposition to use system 2 reasoning.

It is true that people’s perceptions of whether it has been “hotter” or “colder” in their region strongly predicts whether they think climate change is occurring. But their perception of whether the temperatures have been above or below average is not predicted by whether it actually was hotter or colder in their locale. Instead it is predicted by their ideology and cultural worldviews.

The only thing unsatisfying about the motivated reasoning explanation is that it starts in medias res.  One can observe the (disturbing, frightening) effects of motivated reasoning now; but what caused climate change risk perceptions, in particular, to become so vulnerable to this influence to begin with?

I’m not sure whether one needs to know the answer to that question in order to start to use the knowledge associated with such studies to design communication strategies that dissipate confusion and conflict over climate change. But I am sure that without a good answer, the risk that such conflicts will recur will be unacceptably high.

5. Goldilocks

The worst of all explanations for political conflict over climate change is “all of the above.”  The “phenomenon is complex; there’s lots going on!” etc.

I think people who make this sort of claim say it because they observe (a) that there are genuinely lots of plausible hypotheses for climate change conflict, (b) genuinely lots of confirming evidence for each of these theories, and (c) indisputably disconfirming evidence, too, for most (I'd be quite willing to believe all) of them.  They take the conjunction of (b) and (c) as evidence of “multiple causes,” and “complexity.”

This would be fallacious reasoning, of course.  One can nearly always find confirming evidence of any hypothesis; to figure out whether to credit the hypothesis, one has to construct & carry out a test that one has good reason to expect to generate disconfirming evidence in the event the hypothesis is false. Thus, the conjunction of (b) and (c) in regard to any particular plausible hypothesis is simply evidence that the hypothesis in question is false—not that “lots of things are going on.”

In fact, “all of the above” is worse than confused. When one adopts a "theory" that allows one to freely adjust multiple, offsetting mechanisms as necessary to fit observations, one can explain anything one sees.  That’s not science; it's pseudoscience.

Session reading list.

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Reader Comments (25)

So I really enjoyed this post, and found myself nodding along until part five, where I suddenly felt much less sure of the argument. I would be grateful if you could help to convince me:

"One can nearly always find confirming evidence of any hypothesis; to figure out whether to credit the hypothesis, one has to construct & carry out a test that one has good reason to expect to generate disconfirming evidence in the event the hypothesis is false."

Right, so as you said on Twitter, we need to heed Popper, and look for critical tests to try to falsify hypotheses where possible.

But what if critical tests, though desirable, just aren't appropriate or possible (ontologically, methodologically or even financially)?

Surely there are phenomena (such as reasons for not processing and acting on the implications of anthropogenic climate change) that are sufficiently 'complex'(because there are multiple inter-related causes; emotions, values, commitments, norms & biases that are eminently conflatable and blur lines of causality) such that a hypothesis that accounts for the existence of that phenomena cannot be stated clearly enough to credibly lend itself to a critical test?

"Thus, the conjunction of (b) and (c) in regard to any particular plausible hypothesis is simply evidence that the hypothesis in question is false—not that “lots of things are going on.” "

False? Isn't that too strong/definitive? Where there are instances of both confirming and discomfirming evidence isn't the point rather that the explanation is limited, or contextual, or explains part of the phenomena in question?

"In fact, “all of the above” is worse than confused. When one adopts a "theory" that allows one to freely adjust multiple, offsetting mechanisms as necessary to fit observations, one can explain anything one sees. That’s not science; it's pseudoscience."

It is not science in the Popperian sense, but it doesn't follow that it's pseudoscience. If the theory in question calls upon multiple evidence sources and gives due care and attention to the explanatory scope of that evidence, is there any reason why one cannot attempt to explain part of a given phenomena? Is some kind of inductive reasoning not entirely appropriate here? If so, the adjustment in question is not some kind of slippery pseudoscience but more about adjusting degrees of epistemic warrant in light of one's understanding of the evidence base and how it relates (or doesn't) to whatever needs to be explained. (There might even be a case for some sort of Bayesian logic).

My impression is that where the issue in question is how 'the public' perceive and act on their understanding of climate change, anything resembling a critical test or deductive explanation will have to filter out too much of the inherent complexity (a term I now use self-consciously, but steadfastly in light of the above!) to explain what is really going on.

That's not a council of methodological despair, but surely part of addressing the climate challenge is deciding how much epistemic warrant we should reasonably expect for any given course of action. If we really need to frame all our hypotheses so that they can, in principle, be disconfirmed, doesn't this needlessly compound an already near impossible problem?

March 11, 2013 | Unregistered CommenterJonathanrowson

I'd only want to add, again, another reason, in addition to the "four hypothesized causes for conflict over climate change", and that is 5) the politicization of the scientific establishment, the evidence for which abounds in various sites of climate change skeptics, and in various statements of scientists themselves, the archetype being the infamous "scary scenarios" quote from Stephen Schneider. These may not constitute strictly scientific evidence themselves, though they're certainly evidence as we commonly understand the term, but it would be interesting to consider how we might test such an hypothesis in a controlled manner -- insulated, that is, from the possible prior bias of the testers themselves.

March 11, 2013 | Unregistered CommenterLarry

Maybe even better support for (4) comes from this paper (
since it's longitudinal and identifies different patterns along "levels of engagement". It's worth noting that local conditions were not insignificant predictors of attitudes among the low engagement group, though.

March 11, 2013 | Unregistered CommenterScott Johnson

"The materials read this week can be understood to present evidence relevant to four hypothesized causes for conflict over climate change: [...]"

There are of course other hypotheses. That different groups have different social networks by which they obtain information, that they use different modes of reasoning, that they set different quality thresholds that evidence has to meet, etc.

"In particular, they were more likely to appreciate what Bostrom et al. described as the “two facts essential to understanding the climate change issue”: that “an increase in the concentration of carbon dioxide in the earth’s atmosphere” is the “primary” cause of “global warming,” and that the “single most important source of carbon dioxide in the earth’s atmosphere is the combustion of fossil fuels.”"

This selection looks at the issue from only one of the viewpoints - in other viewpoints there are additional facts essential to understanding the climate change issue. For example, that the projected amount of warming any location will experience is very uncertain; that the uncertainty is not due to uncertainty about the basic CO2 mechanism but the feedbacks, which are poorly understood; that all of our measurements and models have serious biases, limitations, and error bars that require complicated (and controversial) corrective processing to fix, and that the political question is the trade-off between the cost/risk of damage to economic development from climate change versus the measures taken to prevent it.

Knowing the first two 'facts' is not sufficient to understand why there is a controversy. Without knowing the reasons for the controversy, it is impossible for the democratic decisionmaking process to come to a valid judgement on it.

"The worst of all explanations for political conflict over climate change is “all of the above.” The “phenomenon is complex; there’s lots going on!” etc."

I agree that if there's no more evidence for it than that all of the individual hypotheses are disconfirmed by some of the observations, then you can't conclude this. It doesn't mean it isn't true, though.

The same of course can be said for the universal "unknown unknowns" hypothesis: that none of our proposed hypotheses are the explanation and something else we haven't even thought of it really going on. It too can be used to 'explain' anything, although it is really a lack of explanation, a failure to draw a conclusion, and not an end to enquiry.

A mixed model is possible, if positive evidence is provided to show that different mechanisms are at work in different cases (which very likely requires identifying the mechanism specifically - hard to do), and if some explanation is offered as to when and why each alternative takes place.

March 11, 2013 | Unregistered CommenterNiV


; that the uncertainty is not due to uncertainty about the basic CO2 mechanism but the feedbacks, which are poorly understood;

I read quite frequently in the "skept-o-sphere" that there is very much uncertainty about the basic CO2 mechanism. I read this from people who seem to have a very sophisticated understanding of physics - or at least who seem quite intelligent and who study the physics quite intently. Not a handful of folks - quite a few viewed within the full context of the "skept-o-sphere."

So, in other words, "There are of course other hypotheses. That different groups have different social networks by which they obtain information, that they use different modes of reasoning, that they set different quality thresholds that evidence has to meet, etc."

I could also include hypotheses that we can't measure "global" warming, that the measurement that has been done is flawed at best, cooked at worst.

Your selection looks at the evidence from a limited viewpoint. Understanding the "facts" you stated is not sufficient for understanding the controversy - unless you would have it that people should just accept your "authority" and an "expert."

March 11, 2013 | Unregistered CommenterJoshua

@Scott-- thx! that study deserves an addendum!

March 11, 2013 | Registered CommenterDan Kahan

@NIV: agree that it is important to distinguish between "multiple causes; complex" & Goldilocks. Poorly worded, communicated idea here, as @Jonathanrowson's observations point out. Will try to reformulate .. let's see ...

March 11, 2013 | Registered CommenterDan Kahan

I agree with NiV about there are other veiwpoints. But I also agree with cultural cognition is still the best choice.

One of the probems is the term climate change itself. Consider that wind farms cast a wind shadow that technically meets the definition of climate change. Where as what persons are really explaining when discussing GHG's is anthropogenic global warming. Poor definitions are almost guarenteed to cause heated discussions, not enlightened discussions. One should consider what Popper says about unfalsifiable and see how CC fits this definition.

Another problem is that few realize, or wish to discuss, that AGW or CC as presented in AR4 is an argument from ignornace, not a measure of performance or a performance of measurement such as the efficacy of a vaccine. Many fail to realize that there are two actual parameters that are used to explain two variables, manmade and natural. However, these two parameters are not independent as is a necessary constraint for solution. Thus, the arguement from ignornace. However, this means that those opposed, and I would maintain from sheer contrariness, there will be those opposed for almost any policy, have a ready made weapon and ammo.

Of those two parameters, both have known, in the Climategate emails and in peer reveiwed literature, problems that are contrary to assigning confidence, if they were independent, which they are not. This means that those who do understand the science can be in the group that are sceptical for the simple reason that "extraordinary claims require extraordinary evidence." I, and many of the luke warm sceptics are in this group and discuss where we agree or not.

The best question to ask to understand our position is to ask yourself what would it take to change your mind. I think the post needs this as well. For a luke warmer, it is what will it take to convince yourself one way or the other. For the alarmist, what will it take to make you conclude AGW does not exist in a measureable form. And for deniers, what would it take to convicve you that it exists and is measureable.

If you cannot answer this question, there are two options. One can study to learn what it takes. One can conclude that oneself is an advocate and has a closed mind to science.

Thus I find that in a way this whole post misses a very important point. Though one can substitute climate change and UN for vaccine and Merck, it is really an apple and orange comparison. There are two points to this. The first is that because of the lack of measurement, local and visible should work because it is like a vaccine, where as a world wide carbon scheme is not. This is a model failure. It should be unsurprising we find failure. The second point is that looking at the potential and acknowledged sales fatigue from press releases of the neo-malthusians for the past 50 years, I do not think a bias free test can be accomplished without a way to measure this fatigue and compensate for it. I do think such a bias free test can be done.

Disclaimer: I started reading Ehrlich and others in high school. What they convinced me of was that they were wrong on the most important point. Something could be done. In fact, that is the reason I got my degrees and for 25 years I have been an environmental engineer. The other important item I learned from Ehrlich and the others was a from critique of their works by someone who explained their failures as model failures and why. I do not think cultural cognition is a model failure, but rather the opposite. It needs to be expanded to include points here and elsewhere by Larry, NiV, and Joshua.

March 11, 2013 | Unregistered CommenterJohn F Pittman


We need to stop finding points of agreement.That isn't supposed to happen in the blogosphere.

I agree with you w/r/t the fundamental problem of terminology. Agreeing to a definition of terms is a necessary ingredient; it is widely missing in the discussion, and both sides exploit that problem to confirm biases and avoid substantive dialog (after all, substantive dialog really mucks up motivated reasoning).

While you say that "Another problem is that few realize...", I actually think the problem you go on to describe is actually a problem of definition of terms. In other words, when a climate scientist refers to climate change, they mean the combination of known and controlled for natural variables as well as anthropogenic variables. Now within that definition there may well be strong disagreement about probabilities and magnitude of the different variables, respectively, the discussion rarely gets down to a good faith discussion in that regard. Instead, we have "skeptics" claiming that climate scientists ignore natural variables or that the "science is settled," and we have "realists" saying that "skeptics" necessarily deny any anthropogenic forcings.

The best question to ask to understand our position is to ask yourself what would it take to change your mind. I think the post needs this as well. For a luke warmer, it is what will it take to convince yourself one way or the other. For the alarmist, what will it take to make you conclude AGW does not exist in a measureable form. And for deniers, what would it take to convicve you that it exists and is measureable.

Again I agree - i think. By that I mean I think I approach the same concept by way of saying that a necessary component of proving a thesis is to internalize and effectively argue against any plausible "naysayers." In other words, I think of the "naysayer" as representing a plausible argument that might change your mind, were it not for...... your rebuttal to the plausible naysayer.

So my question to you would be.... What would it take you, as a luke-warmer (?), to change your mind?

I agree that the analogy to issues such as vaccines is a bit thin (IMO), because of the type of problem and magnitude of related uncertainty. That doesn't mean, however, that I don't think it is very likely that motivated reasoning is the best explanation for controversy about climate change, just as it is the best explanations for other controversies about issues that overlap with social, political, personal, ideological, and psychological influences on identity formation.

[rant on]

I would, however, augment the theory about motivated reasoning as causal with the fundamental role that pattern-finding plays in our cognitive processes. In addition to those other influences that push us towards motivated reasoning, I would add the influence of our natural tendency to find familiar patterns to make sense of the world. We cannot make sense of the world without finding patterns. We are very uncomfortable when we cannot find those patterns. We don't like ambiguity. As one personal example, I think that the pattern-finding nature of cognition is one reason why, in addition to the motivated reasoning of my interlocutors, I am so often told by "skeptics" that I believe things that I don't believe, and never gave any indication that I believe. My interlocutors take ambiguous statements that I make and fit them into some preconceived stereotype of what a "warmist" believes. It is why, IMO, along with that mischaracterization of my beliefs, I am told that I have values that are different than those of my interlocutors - when in fact, as much as I can tell, our values are probably very similar for the most part.

[rant off]

I will disagree with you about the "sales fatigue," however (there, doesn't that feel so much better?). I don't see much evidence of that phenomenon. I think that the argument about "sales fatigue" is mostly a product of motivated reasoning. Although I think that it is a logical hypothesis, I don't see the supporting evidence, and I think that people who see it, do so because they are predisposed to do so. In line with your suggestion - the argument that would change my mind would be one based on an elaboration of evidence.

March 11, 2013 | Unregistered CommenterJoshua

@Jonathanrowson & @NiV:

Does this addendum on "Goldilocks" help?

March 12, 2013 | Registered CommenterDan Kahan

Joshua, I agree with you. But I may agree with you differently than you may agree to.

I do not see a difference with pattern finding and cultural cognition. I see cultural cognition as the model, pattern finding as a potential explanatory mechanism for some observations. Part of the skill of meeting regulations is pattern/definition matching/contrasting.

I would argue that pattern finding/matching as either model or mechanism indicates that "sales fatigue" should be real. I could be wrong. I think it should be shown one way or another as NiV has correctly, IMO, stated that there can be other veiwpoints that MAY mean there are additional facts essential to understanding the climate change issue. I think of sales fatigue as one that should be resolved if true. If not true, one will still end up with more explanatory power in the model.

I also see sales fatigue as a mechanism of cultural cognition. It does not surprise me that you do not find it, where as I do. The answer for me is not that it does not exist, but that it exists with in a cultural cognitive context. That is one of the reasons I found the model of cultural cognition as able to explaim more and not a model failure with respect to points made by myself, Dan, you, Larry, and NiV.

Though it may be more true that sales fatigue is the after effect of pattern finding for someone like myself. So I see your point of pattern finding and cultural cogniton as having more explaination than standing alone. I know I suffer from sales fatigue. After all, I have to keep track of the environmental advocacy from the neo-malthusians because they do have a voice, they may be correct, and regulatory agencies need to consider what they say even if shown later to be wrong. Otherwise our protection is not as good as it should or could be. Since I know it is true for myself, and think that pattern finding may well be a mechanism for cultural cognition pathways, the explanation with the most power is one that explains your observation and mine. That would be that pattern recognition fits within our model of cultural cognition.

March 12, 2013 | Unregistered CommenterJohn F. Pittman

Joshua to the question "So my question to you would be.... What would it take you, as a luke-warmer (?), to change your mind?" The hardest one to convinve me of is that CO2 has no effect. This is contrary to my professional knowledge and experience. Thus the answer to get me to go either way from luke warm is evidence. Nummerate evidence that does not have obvious model failures as does the current IPCC reports. These failures are not black and white, nor fasification of the reports. But realize, I can claim that 1.7C is a reasonable number of 2XCO2 for equilibrium climate sensitivity and be within the constraints of the IPCC reports. To convince me it is 9C, or less than 1C, or a value of your choice, requires evidence. It would need to be broad, deep, and self consistant. This does not apply to the two disciplines used to attribute 2XCO2 to that 3C. In fact for me, it cannot be said to be broad deep and consistant for any particular number from <1 to >10. So the answer is the same for either direction. When we get agreement that 2XCO2 is say 1.6C to 2.4C with 50%+ explanation from 1.9 to 2.1 with well defined models that do not have circular arguments due to assumptions, or have known problems in implementation that have known to be untrue since the 1930's, then I will say it is time to do something. Because with the range that is in the IPCC reports, I can choose a number that is scientific and means we do not need to do anything until 2100.

March 12, 2013 | Unregistered CommenterJohn F Pittman


Number of related reactions to "politicization of scientists" hypothesis (PS):

1. Is scientific establishment genuinely more politicized now than was, say, 30 yrs ago? Or 40 or 50? Why not less? Think of how enmeshed scientists were w/ national defense from Manhattan Project to end of Cold War; think relatedly of scientists & nuclear power.

2. Would PS have explained public controversy over nuclear in 1970s & 1980s? If so, is it possible that PS is not really an explanation but a consequence of controversy? That is, whenever there is controersy over some risk issue for another reason, one side or the other will form view that "science establishment" position is "political"?

3. Why does PS select *climate change* as focus of controversy? Why not something else -- high-power transmission lines & cancer, say -- or dozens of other things? What about variance in risk perception across place? Does PS explain GM food controversy in Europe? Then why do we not have same controversy in US? If answer is that "climate change is sui generis" -- why believe that? Or what to make of the interconnections -- particularly cultural ones -- in peceptiioins of packages of risks?

March 13, 2013 | Registered CommenterDan Kahan

Good questions, Dan. My responses:

1. I don't know whether or not PS is worse now than at some time in the past. The whole point of PS, after all, is that scientists (and the social apparatus that surrounds them) are human too and so are affected by intense political controversy over scientific issues in the cultures in which they're embedded. As far as I'm aware, for example, there was no particular scientific controversy over the Manhattan Project, but there was over "Star Wars", and there too I think it would just be realistic to expect some component of the scientific argument to have been affected by its politicization. Similarly with nuclear power -- until fairly recently, as I've said, when the issue of Climate Change has made continuing opposition to nuclear power less tenable. It would be an interesting project, for example, to see whether or not the opinions of scientists re: nuclear power has changed over the years that climate change has risen to political prominence.

2. This is a particularly good question. It suggests that the science establishment itself is more or less immune to public controversy, and that its apparent politicization at any one time is simply an illusion from the perspective of the combatants. How would you test that hypothesis? Has the position of the scientific establishments changed from one period to another? If so, have the facts or evidence changed in significant ways, or not? My guess at the answers would be yes and no, respectively, but it's just my guess.

3. I don't think that climate change is sui generis -- I think it just happens to be an issue around which a lot of political symbolism of one sort or another can gather (e.g., "wasteful lifestyles", "overconsumption", "SUVs", "environmental exploitation", etc., etc.). But I would expect to find, and be alert for, some degree of politicization of science around other, less charged, issues as well, again on the simple grounds that scientists and their supporting apparatus are "human too". (Note that this implies they're affected by cultural differences in controversy, just as is everyone else in the surrounding culture.) I'd agree, certainly, that scientists are also affected by what you've called professional norms, and these can often be at odds with their political values and goals. And when they are, such norms have a much better chance of prevailing when the issue is a) less politically charged, b) more specifically factual or more focused on a narrow matter, c) generally more amenable to answers in terms of those norms -- i.e., amenable to disconfirmation or falsifiability. On all those characteristics, climate change unfortunately rates badly.

March 13, 2013 | Unregistered CommenterLarry


I'm not sure that the addendum expresses the idea very clearly either. It's really something much shorter.

Proposed theories need to be falsifiable. A mixture of mechanisms can make a falsifiable theory so long as you are specific about when the different mechanisms ought to apply, but it's quite true that a menu of mechanisms can fit any pattern of observations and cannot make predictions, and so offered as an explanation is pseudoscience.

Of course, it depends on whether the hypothesis is being put forward as a positive explanation in itself, or simply as a negative counterexample to demonstrate that you haven't eliminated all alternative hypotheses. Just because the alternatives are virtually impossible to eliminate does *not* make their proposal pseudoscience. It tells you that you don't have the experimental capability to answer the question yet.

March 13, 2013 | Unregistered CommenterNiV


Well, I only study & don't do ...

Of course, I was aiming at Popper's account, which includes the "falsifiablity" criterion, of the difference between science & pseudo science. "Falsifiablity" is short, yes, and gets the core from which all else radiates out.

But it's useful, sometimes, to trace out the rays & get a good look at what they are illuminating. That's what Popper does w/ his critique of pseudoscience -- the primary instances of which for him were Marxism & Freudian psychoanalytic theory. I think it is useful to call attention to ways of engaging the question "why the climate change conflict?" that partake of the problems of pseudoscience, two of which are the promiscuity of offsetting mechanisms -- which do indeed make any account one can give immune to being falsified -- and the "that's only one part of the story -- there is a lot going on," which tries to assert everything is true "in its place," and which therefore also means nothign can be falsified & no progress ever made.

Actually, as useful as "falsifiability" is, I think it is *too* short. People who haven't read Popper or at least thought about the problems he was addressing usually fumble & get confused when they try to explain the concept. (Have you not heard a confused person ask, "but how to you believe in something you've falsified?")

They'd be best off reading Popper, who in the short essay that I linked to (in the last word-- pseudoscience--of the original post), sets out the sciences vs. pseudoscience argument in brilliant, accessible, engaging terms. (Popper was an essay writer; his books are the parts of dismembered essays spread out chaotically 100s of dense pages.) Still not as short as what you have jotted out, btw, which I think is fine if someone already understands what you are saying.

aI'd say that if one doesn't have someone who has time or inclination to read Popper (a busy person who does want to learn), rather than saying "science requires a hypothesis to be falsifiable," it helps to convey the idea that learning empirically depends on combining observation w/ a valid inference:

"If you want to figure out whether something is true, think about what you would expect to see if so but not otherwise & find it; then think what you would *not* expect to see but believe you'd likely otherwise find, & conduct a search that you'd reasonably expect to flush it out if it's there. If you can find the 1st & can't the 2d, then you can have *more* reason to be confident that what you believe is true than you had before."

March 13, 2013 | Registered CommenterDan Kahan

Yes, I agree that "falsifiability" as an answer is only really comprehensible to someone with some understanding of the philosophy of science, which, sadly, not enough people have. I was making assumptions about the real audience here, but as I'm operating blind it's perhaps not suprising that I get it wrong some of the time. :-)

I think I'd still split the explanation into two - one to say "falsifiability", and the other to explain the need and significance of falsifiability if it should prove necessary. To a non-scientific audience I'd put it differently, and probably at much greater length. (I can sometimes do clarity, but I struggle with conciseness!)

But if you're talking to scientists to discuss how they go about communicating, shouldn't they already know basic scientific philosophy? I know that in practice they often don't, but for those cases I think there are bigger problems than how well they can communicate climate science, which really ought to be addressed first. In fact, fixing that might help with the climate communication part as well.

For example, what sort of scientist says something like: "Why should I make the data available to you, when your aim is to try and find something wrong with it"? It was the scientist's apparent utter incomprehension of the conflict this attitude has with scientific principles that others regard as bedrock that was so shocking, and that made the quote so effective in the climate wars. That's an example of a dramatic failure of science communication brought about by lack of understanding of (or agreement on?) scientific philosophy - but whether it was the statement itself or the sceptics broadcasting of it that polluted the science communication environment I'll leave to your students to discuss. Certainly, many people seem to disagree on the need for falsifiability.

The 'Wason selection test' experiment says that people do better on recognising the need to falsify claims if you set it in a social/motivational context rather than an abstract/scientific one. People follow the logic when they're policing a social rule, but get it wrong when they're trying to draw a conclusion. That's a line of thought that could perhaps be explored further.

March 13, 2013 | Unregistered CommenterNiV

I suspect either (a) the science establishment is & always has been political in an important sense that can't be avoided by any institution that occupies an important place in society & that this kind of politicization hasn't impeded science over much (on net probably helped it, certainly) in its mission to acquire knowledge; (b) the science establishment is political in a unique sense today but has been for the last 75 yrs or so as a result of the nourishing of it by govt for purposes of turning scientiic knowledge into war-making power (read Dyson's exellent book Turing's Cathedral for a glimpse -- von Neumann, as brilliant a scientist as ever lived, clearly sells his soul-- *to learn more* ... tragedy of most compelling sort...); or (c) both. Yet I suspect none of these is a very satisfying explanation for climate or for divisive cultural controversies over risk. Each is so normal -- and so is the combination of all -- that the public doesn't even notice. Certainly none of this has shaken confidence in science generally, right?

March 13, 2013 | Registered CommenterDan Kahan

@NiV: I agree w/ all you say. Who knows who the audience is?! I hope it is varied actually; any smart person strange enough to think this is initeresting is welcome! I stumbled, writing for such a person, in trying to make use of understandings you are adverting to.
Maybe 1 1/2 more points on that:

1. Complex theories -- ones that posit interaction of various factors -- obviously don't defy valid empirical proof; that is imprtant point. They do create a conceptual/practical difficulty that is related to Goldilocks & Goldilocks Leviathan, though, since the multiplication of interacting mechanisms can lead us down path toward overdetermined assemblage of moving parts. So it's clear what the appeal of parsimony is. Not just elegance of simplicity (complexity can be even more elegant, I think; ask Mandelbrot) but the displining effect of it on the exercise of really taking evidence seriously.

1.5. You are right that a claim that admits of testing but that can't currently *be* tested b/c of limits in the capacity we have to observe & measure can't be rejected as "false." But it is the case that until our technology catches up, such claims remain stuck in the infancy (or adolescence) of conjecture. Physics historically has handled this *very* well. "Experimentalists" *design* experiments well before anyone can imagine them being carried out; they get published & afforded tremendous recognition so long as they are valid -- that is, so long as they describe what sort of observation *would* support an inference that some hypothesis is correct. Think of Bell's Inequalities -- the core of a design for testing & refuting "hidden variables" as an alternative to quantum mechanics that didn't get tested for over 20 yrs. The problem, though, is if someone has a hypothesis that in theory could be tested by but almost certainly won't *ever* be testable b/c of unrealistic burden of observation necessary. I think that's one thing that is objectionable about string theory. That's not pseudoscience but it might well be something to look askance at.

March 13, 2013 | Registered CommenterDan Kahan

"complexity can be even more elegant, I think; ask Mandelbrot"

I have a theory that our aesthetic sense is an evolutionary mechanism that rewards the detection of simplifying principles. Simple with a simple appearance is ugly (e.g. a square). Genuine complexity with a complex appearance is ugly (a random mess, white noise). What appears beautiful is apparent complexity with a simple underlying order, and it is the process of (subconscious) recognition of that order that gives us pleasure.

Hence the beauty of fractals, which initially appear complex but are actually very simple. Similarly with symmetry. It explains the connection with mathematical aesthetics, in which an apparently complex problem being resolved into straightforwardness by an unobvious insight is also called "beautiful" - a usage that commonly confuses people who don't understand mathematics.

It makes obvious evolutionary sense, and gives a neat explanation for what at first seems a very impractical phenomenon. Why should nature red in tooth and claw bother to design our brains so we enjoy the colours of a sunrise, or music?

And yes, I agree that parsimony is more than just aesthetics - it has a practical purpose. Over-determined theories, "curve-fitting", epicycles, there are many terms for it. To court controversy again - it's the thing sceptics object to in the weather-is-climate stories the media is in love with, in which every unusual weather event is somehow connected as a consequence of global warming. Most climate scientists reject that one too, but it it is persistently popular nevertheless. Human nature, I'm afraid.

March 13, 2013 | Unregistered CommenterNiV

@NiV: actually, you got a citation for that Wason Selection Test experiment?!

March 13, 2013 | Registered CommenterDan Kahan

Wikipedia lists the references - Cosmides and Tooby. (I've seen the phenomenon discussed in other more reputable sources, but Wikipedia is more immediately accessible at the moment.)

March 13, 2013 | Unregistered CommenterNiV

Dan, you say:

Yet I suspect none of these is a very satisfying explanation for climate or for divisive cultural controversies over risk. Each is so normal -- and so is the combination of all -- that the public doesn't even notice. Certainly none of this has shaken confidence in science generally, right?

But, after all, you're engaged in the science of science communication, and suspicions shouldn't be enough, should they? From my perspective, this seems naive in its faith in both the science establishment and the public's response to its politicization, which I suspect is actually at the heart of the problem here. This is, in other words, a distinct hypothesis from the pure "group loyalty"-on-the-part-of-the-public-but-not-the-science-establishment hypothesis, and it's one that, even if only a part of the problem, makes the whole SoSC project less tractable, which may be why it's resisted.

The problem in finding a way to test either of these hypotheses comes down to the problem of finding a way to measure the degree to which the scientific establishment is itself under the sway of cultural cognition, in the judgments and positions it supports. Of course, if you just assume that it isn't -- as I think the Cultural Cognition project does -- then you make that part of the problem at least go away. But at the cost, or at least risk, of turning the SoSC project into just another one-sided exercise in political/cultural persuasion, which then eventually will be seen as that, like so many other, similar campaigns.

March 13, 2013 | Unregistered CommenterLarry

@NiV -- thanks! For an article on motivated reasoning & Wason test, take a look at

Dawson, E., Gilovich, T. & Regan, D.T. Motivated Reasoning and Performance on the Wason Selection Task. Personality & Social Psychol. Bulletin 28, 1379-1387 (2002).

March 13, 2013 | Registered CommenterDan Kahan


Thanks for your responses from March 12th. I've been kind of swamped - and those comments will require due diligence before I respond. I hope to get to it soon. Check back from time-to-time if you're still interested.

March 14, 2013 | Unregistered CommenterJoshua

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