How do unconscious fears of disease affect your everyday social life, influencing who you find attractive, who you are prejudiced against, and even how you view yourself?
Mark Schaller is a professor at the University of British Columbia who has done a series of fascinating studies on the links between fear of disease and social psychology.
Schaller argues that our brains have a behavioral immune system – which he defines as “suite of psychological mechanisms designed to detect the presence of disease-causing parasites in our immediate environment, and to respond to those things in ways that help us to avoid contact with them.” The elegance of the behavioral immune system is that it can prevent the deployment of the more familiar physiological immune system – by getting us out of a potentially infectious situation without requiring our bodies to mount an energetically expensive, and potentially losing, battle with bacteria and viruses.
I’ve talked about some of the findings on the behavioral immune system on my Psych Today blog (see below for links)
But just today Schaller himself wrote about the behavioral immune system for Scientific American. Schaller is a talented writer a deeply thoughtful scientist. In the article, he reviews research linking fear of disease to prejudices (against old people, obese people, people in wheelchairs, and people from exotic foreign places), to personality self-ratings (people who are worried about disease rate themselves as less extraverted, and people who live is places with more disease are more avoidant of other people), to attraction (people living in disease-ridden places are more attracted to symmetrical partners), and even to the common phobia of chocolate fudge (well, only when it’s shaped to look like dog feces).
Schaller covers some fascinating research, including findings from a study by Carlos Navarrete and colleagues, showing that fear of disease changes pregnant women’s prejudices differently depending on trimester, in ways that make adaptive sense. As Schaller notes: “A woman's immune system is suppressed during the first few weeks of pregnancy, leaving her body more vulnerable to infection. One consequence is that women are more sensitive to sights and smells and tastes that trigger disgust. Another consequence is that, compared to women in later stages of pregnancy, women in their first trimester show higher levels of ethnocentrism and xenophobia.”
I highly recommend a look at Schaller’s article (the link is pasted below).
Doug Kenrick is author of Sex, Murder, and the Meaning of Life: A psychologist investigates how evolution, cognition, and complexity are revolutionizing our view of human nature.
Related Links from my Psychology Today blog:
The psychological immune system: When seeing me sneeze makes you healthier.
The psychological immune system 2: When it’s healthy to be antisocial