The Psychological Immune System 2: When It’s Healthy to Be Antisocial

Can a mere sneeze make you closed-minded and unsociable? Yes, and here’s why:

Your body’s immune system can help eliminate pathogens once they've entered your body. But cell-to-cell combat with bacteria and viruses drains the body’s resources, and doesn’t always result in a win for the good guys (sometimes disease kills people, despite their immune system’s best efforts). It would be much more effective to simply avoid disease in the first place.

Indeed, following the outbreaks of Swine Flu, Bird Flu, and SARS, people responded not only by washing their hands more frequently, but by staying out of restaurants, parks, and other places that might bring them into contact with others. My family used to frequent a nearby kid-friendly buffet restaurant every week, for example, but we’ve shied away for months now, after an influenza scare made us think of all the other customers as potential disease vectors for my young son and grandchildren.

In a paper published in Psychological Science in March, Chad Mortensen and his colleagues reported on two experiments exploring how thoughts of disease can trigger social avoidance at multiple levels—in ways that can ultimately aid the immune system (by leading us to avoid contact with others). The research demonstrated that merely thinking of diseases led people to (a) think of themselves as less sociable and (b) make more rapid avoidant movements.

In the first study, participants watched a slideshow chock full of discomforting information about contagious diseases. Later, they were asked to rate their personalities along the Big 5 dimensions. Compared to controls (who saw innocuous slides of architecture), those who had been primed to think about disease later rated themselves as less sociable, more disagreeable, and less open to new people and experiences (see the graph attached). This pattern held most strongly for participants who felt generally more vulnerable to diseases (for example, who believed that they catch colds easily) (these high concern folks are shown in the solid line on the graph; the dotted— topmost—line depicts people relatively low in concerns about disease). What’s going on? Mortensen argued that this is an adaptive response: People who view themselves as less social, cooperative, and open are indeed less likely to approach strangers. By redefining themselves in this way, people worrying about disease reduce the possibility of placing themselves in a position to be infected by all those infection-laden sneezing and coughing other people out there.

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Keeping other people at arms length: Embodied avoidance

A second experiment showed how thoughts of disease could change simple motor behaviors as well. Again, some participants saw a disease-y slideshow, controls saw the neutral set of slides. Afterwards they all saw photographs of other people on a computer screen. The photos were briefly interrupted by circles or squares, and their task was to move their hands toward or away from themselves to press buttons indicating which shape they had seen. Those who viewed the disease slideshow were especially quick to make the avoidant movements while the photos of people were on the screen, suggesting that thoughts of disease can incline us to avoid others at a very basic motor level.

The results of these two experiments fit nicely with Schaller and his colleagues’ work on the behavioral immune system* (discussed along with some fascinating findings in my last posting, suggesting that merely seeing pictures of disease-y people can trigger an actual immune reaction, which you can read about by clicking here). These different sets of findings are beginning to build a case that our responses to disease are affected by unconscious biases in perceptions and behaviors that help prevent disease transmission. And Mortensen argues that there’s a practical benefit to understanding the psychology underlying disease avoidance: These findings could help health policy makers design more effective social interventions—to help people better manage their decisions and actions during deadly outbreaks of flu and other diseases.

References

Mortensen, C.R., Becker, D.V., Ackerman, J.M., Neuberg, S.L., & Kenrick, D.T. (2010). Infection Breeds Reticence: The effects of disease salience on self-perceptions of personality and behavioral avoidance tendencies. Psychological Science, 21, 440-447.**

Schaller, M. & Duncan, L.A. (2007). The behavioral immune system: Its evolution and social psychological implications. Pp. 293-307 in J.P. Forgas, M.G. Haselton, & W. Von Hippel (Eds.) Evolution and the social mind: Evolutionary psychology and social cognition. New York: Psychology Press.

Psychological Immune System I: Why sneezing me sneeze makes you healthier: Click here to read earlier post describing Schaller et al.'s recent research - which shows that merely seeing pictures of disease-y people can trigger an actual increase in immune system effectiveness.

**Mortensen’s research was supported by grants from NIMH and NSF.

Linguistic caveat

* Schaller and colleagues use the term “behavioral immune system,” not “psychological immune system,” which apparently has previously been used with a slightly different meaning by social psychologists Dan Gilbert and Tim Wilson, and by clinical psychologist Herman Kagan (see references below). Gilbert and Wilson use it to refer to cognitive biases that protect us from negative emotions.

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Gilbert, D.T., Blumberg, S.J., Pinel, E.C., Wilson, T.D., and Wheatley, T.P, (1998) "Immune Neglect: A Source of Durability Bias in Affective Forecasting" Journal of Personality and Social Psychology, Vol 17, No. 3 pp. 617-638.

Kagan, H. (2006). The psychological immune system: A new look at protection and survival. Bloomington, Indiana: Authorhouse.

Psychological Immune System. Wikipedia.