Studying the Effects of the Behavioral Immune System on Anti-Immigration Attitudes: Public Health Watch Report

The events in Charlottesville, Virginia this weekend have many across America asking many questions, including: “How does racism and bigotry spread?”

The answer may be in our immune systems—or, more specifically, our “behavioral immune systems.” A theory first proffered by psychology researcher Mark Schaller, PhD, in the early 2000s, the behavioral immune system refers to a series of psychological mechanisms designed to alert organisms to the presence of disease-causing parasites in their environment and initiate responses to prevent contact with them. Examples of the psychological mechanisms employed by the behavioral immune system include sensory processes, such as the smell of an odor, as well as affective/cognitive/behavioral responses, including feelings of disgust and fear (of contamination, for example).

Recently, researchers from Temple University in Philadelphia and the University of Aarhus in Denmark expanded upon this concept, and attempted to determine what role, if any, the psychological mechanisms of the behavioral immune system played in shaping our political and social views—specifically, our feelings about immigrant populations. The study, the results of which were published in the May 2017 issue of the American Political Science Review (APSR), is topical to say the least. Several countries in Western Europe, including Denmark, have been faced with questions about how to properly manage the recent influx of migrants from the Middle East and North Africa.

And here in the United States, of course, the issue of immigration—and who is or isn’t welcome on these shores—was front and center during the unrest in Charlottesville.

“We were interested in understanding how people’s psychological predispositions shape their political attitudes,” study coauthor Kevin Arceneaux, PhD, Professor of Political Science and Director of the Institute for Public Affairs at Temple University told Contagion®. “Decades of neuroscience research shows that people’s decisions are often pushed in particular directions in ways that they do not fully perceive. We were particularly interested in understanding whether aspects of how our minds evolved could provide clues about which predispositions would be more likely to influence political attitudes.”

For their research, Dr. Arceneaux and his colleagues surveyed more than 4000 subjects in both the United States and Denmark to “test how the effects of the behavioral immune system on anti-immigration attitudes compare to and interact with the factors that political scientists consider fundamental to the politics of immigration and ethnic tolerance.” Study subjects were shown images related to infection risk and disease, and the authors measured their sensitivity to these stimuli via their skin conductance response.

In general, they found that those subjects who displayed higher degrees of disgust and fear in response to images of excrement and bodily fluids (as sources of infectious disease), for example, were more likely to have negative attitudes toward immigrant populations. Why? In essence, because their behavioral immune systems tell them that anything that is different is a source of infection and should thus be feared and avoided. This response, the authors believe, extends to human beings that look different (for example, those with physical abnormalities or even a certain skin color), at least among a significant number of white study subjects.

“When concerns about disease are made salient, people’s first reaction is often to hunker down and avoid what they perceive the threat to be,” Dr. Arceneaux explained.

Not surprisingly, the mainstream media has sought to simplify the research team’s findings, attributing “fear of immigrants” to an “immune response” (Forbes) or suggesting that the behavioral immune system “explains xenophobia” (Vice). Of course, it’s not that simple. In fact, as the mechanisms of the behavioral immune system are unconscious mental and physical processes, the authors of the APSR paper are quick to point out that it is only one of many forces (including parental socialization and education) that help shape ideologies.

Still, can increased understanding of the role of the behavioral immune system reveal ways to address issues of bias in society? Dr. Arceneaux and his colleagues are optimistic. “[We believe that] if people are made aware of their biases, it motivates some to correct for them,” he said. “[And], to the extent that people come into contact with individuals from other groups and become familiar with them, they are less likely to unconsciously categorize these individuals as a potential disease threat.”

That’s not exactly promising a cure for race-fueled violence but, after the last few days, we’ll take it.

Brian P. Dunleavy is a medical writer and editor based in New York. His work has appeared in numerous healthcare-related publications. He is the former editor of Infectious Disease Special Edition.