Mystery solved? Age, political knowledge, and political polarization

1. Age and polarization. “Yesterday,”tm I reported an intriguing finding on the interaction between age and political polarization.  The finding was that partisan polarization increases with age.

This is not the same thing as saying that older citizens are “more conservative.”   That effect is already familiar to political scientists, who debate whether it is a consequence of the personalityshaping effects of aging (the “personality theory” or “PT”) or instead a lasting effect of exposure to the political climate that prevailed at some earlier, more impressionable point in older people’s lives (the “cohort theory” or “CT”).

The effect I reported had to do with the increased intensity of partisanship conditional on age. There may be (or may not be) “more” conservatives in absolute terms among the oldest cohort of citizens. But the data  posted suggested that as people age they became more intensely (or reliably?) partisan compared to younger citizens with the same partisan identity (“conservative Republican,” “liberal Democrat,” etc.).

I was surprised by this result and not sure what to make of it, so I invited feedback.

2. Political knowledge, age, polarization. One explanation, advanced on Twitter and seconded by others off-line, was that “political knowledge” might be correlated with age.

It’s a well established finding that citizens with greater political knowledge (or sophistication) express political preferences that are more in line with their self-identified political ideology. Older citizens have (necessarily) been around longer and thus had more time to work through the relationship between their political outlooks in general and their stances on particular issues such as climate change and gun control.  This age-dependent coherence between self-reported political outlooks and policy preferences can be expected to manifest itself in the pattern I reported between age and intensity of partisan policy stances.

This explanation—let’s call it the “Kalmoe conjecture”—struck me as interesting but not particularly plausible. To test it, I rummaged around in old CCP datasets until I found one that had both a policy preference battery and a “political knowledge” one.

The latter is conventionally measured with a set of basic civic literacy items, which are well known to predict ideology/policy preference coherence.

The analysis revealed, first, that there is indeed a correlation between age and political knowledge.

Second, like the relationship of age to policy preferences, the relationship between age and political knowledge (measured with 9-item scale) features more intense political preferences among older than among younger citizens.

Third, when one regresses policy positions on age and political knowledge (as well as the interaction between these two), the relationship between age and intensity of policy positions disappears.  So if one considers, e.g., a young “conservative Republican” and an older one, there is no meaningful difference in the strength and coherence of their opposition to gun control and to mitigation of climate change by restricting carbon emissions. Of course, consistent with zillions of studies, study subjects “high” in political knowledge are more polarized than subjects who are “low”–but that is true irrespective of the subjects’ ages.

3. Huh?


I’m no longer as skeptical of the claim that greater political knowledge accounts for the relationship between age and intensity of policy-preferences.

But I still can’t shake the feeling that there is something wrong with that position.

I think my hesitation is grounded in the highly linear relationship between age and political knowledge.

I have a hard enough time believing that a 75-year-old person , as a result of greater life experience and reflection thereupon, is more politically sophisticated than a 35-year-old one.  But the idea that the former, for exactly the same reasons, is more sophisticated than a 65-year-old seems absurd to me.

It also seems absurd to think that the advantage the 75-year-old has over 65-year-old one is identical to the advantage that the 65-year-old one has over the 55-year-old one, the 55 over the 45, the 45 over the 35 etc.  If political knowledge relentlessly expands over the course of a person’s life, it still must be the case that the marginal growth diminishes over time.


4. Back to PT vs. CT.

Another thing has happened to me over the course of this foray into age and political polarization: I’m now definitely less skeptical about PT (the “personality thesis”) in relation to CT (the “cohort thesis”).

This shift also is rooted in the seeming linearity of the effect of age on partisanship.  (This linearity, it is important to point out, is observable in the raw data, not simply in the regression models, which constrain the effect of age to be linear.)

Again, the cohort theory attributes the greater conservatism of older citizens not to the experience of aging on their preferences but rather to the imprinting of the political spirit of the time in which those citizens came of age (presumably in their 20’s).

If that’s right, the impact of age shouldn’t be so damn linear.  The relative strength of conservative and liberal sensibilities in the general population presumably ebbs and flows.  If CT is right, then, any trends toward conservatism should be punctuated with trends toward liberalism.  We should see a ragged line, not a straight one, when we plot conservatism in relation to age.

The linearity of the march toward conservatism with age is much more consistent with PT, which before now struck me as more of a just-so story than a plausible account of how political sensibilities change as people grow older.

Or at least that is what I think for now.

What do you make of all this?

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