People who believe that political views are rooted in biology are more prejudiced against their political opponents, according to research published in Social Psychological and Personality Science.

The study of 452 U.S. adults found that people who believed biological differences were responsible for differences in political ideology were more likely to desire to avoid the company of political rivals and more likely to oppose political compromise.

PsyPost interviewed the study’s corresponding author, Elizabeth Suhay of American University. Read her explanation of the research below:

PsyPost: Why were you interested in this topic?

Suhay: My current research agenda focuses on how and why people’s political attitudes are related to their embrace—or rejection—of the idea that inequality and difference are innate (as opposed to the product of, e.g., upbringing/culture or, simply, free will). As a general matter, I think this topic is understudied. We’re living in an age where “biological” explanations for all kinds of characteristics and behaviors are resurgent, and, yet, we know very little about how people are linking these factual beliefs to their social and political attitudes.

So, this general interest of mine has been a constant in my life for several years now.

A couple of years ago, I read a book by some “biopolitics” researchers (Hibbing, Smith, & Alford’s Predisposed) where they claimed that exposure to biopolitics research—for example, empirical findings that variation in political ideology is in part the result of genetic variation between people—probably increases people’s tolerance toward their political opponents. (At the time, the authors were also frequently making this claim in academic presentations of their work.) However, to my knowledge, the authors had no actual data to back up their claims. Certainly no published data. My co-authors ran across this “biological attribution leads to tolerance” assertion around the same time as me, and we started corresponding about it.

We were fascinated and a little perplexed. We knew that a lot of previous research on public beliefs about other types of differences found just the opposite: that people who attributed disliked characteristics of other people to “nature” (biology) tended to be more prejudiced toward those people, not less. On the other hand, we also knew that there were some instances where biological attribution and tolerance were associated. The most salient case (and one that I have studied) is biological explanations for variation in sexual orientation. People—at least those in the U.S.—who believe lesbians and gay men are “born that way” tend to have much more positive attitudes toward non-heterosexual people (and their civil rights) than those who believe sexual orientation is the product of upbringing or choice.

Thus, my co-authors and I set out to answer this straight-forward question that, to our knowledge, had never been addressed in a previous empirical study: are people who think variation in political attitudes is innate more or less tolerant toward those who disagree with them politically? Let me add that this is also an important question. Given the high levels of political intolerance right now in the U.S. in particular, it is important that researchers better understand the reasons for that intolerance, with the hope of someday increasing tolerance.

What should the average person take away from your study?

The upshot of our study is pretty simple. Our findings suggest that, in the United States, people who believe that political ideology is innate and unchanging are, on average, (1) more intolerant of the political opposition, (2) less interested in living near the political opposition, and (3) less interested in political compromise.

In a bigger picture sense, I think people should also take away the following from our study and similar ones on causal attributions for other types of human differences: believing that people you dislike or look down upon were “born that way” is more likely to be associated with prejudiced attitudes, not tolerant ones. While there are some examples where biological beliefs and tolerance are related (sexual orientation being the most salient one), the bulk of the evidence suggests this is the exception rather than the rule. When you mix together biological attributions with intergroup rivalries and contempt, the outcome is not likely to be a positive one.

Are there any major caveats? What questions still need to be addressed?

Because our study is the first one on this subject (of which we are aware), there is much remaining work to be done.

First, while our findings are similar across two different, diverse samples, our sample sizes are relatively small for a correlational study and neither sample is a “probability sample” (the gold standard for achieving a representative sample of a population). We encourage researchers to see if these relationships replicate in a large, probability sample of the U.S.

Second, our study is only of the U.S.! We cannot make any claim based on these data that this is a universal relationship. We encourage researchers to study this relationship in other democratic countries—particularly countries with electorates that are polarized along ideological or other lines—to see whether similar results are obtained.

Third, our study is correlational. We cannot (and do not) make any causal claims about how a lay theory of biopolitics and intolerance come to be associated. Do people first develop the idea that opponents’ characteristics (or, perhaps, people’s characteristics in general) are the product of “nature” and then develop intolerant attitudes? Or, does intolerance develop first, with the belief that political differences are innate following later as a post-hoc justification for prejudice? Researchers should study this experimentally.

Is there anything else you would like to add?

Researchers interested in collaborating on replications—such as those mentioned above—are encouraged to contact us!

The study, “Lay Belief in Biopolitics and Political Prejudice“, was co-authored by Mark J. Brandt and Travis Proulx.