Behavioral Immune System Responses to the Obesity Epidemic

Abstract: Throughout human evolutionary history, pathogens have posed a threat to human survival. As a result, people are equipped with a complex physiological immune system designed to detect and destroy pathogens that have entered the body. Several recent studies suggest that, in addition to this physiological immune system, people also evolved a behavioral immune system - a suite of psychological processes designed to prevent pathogens from entering the body in the first place. In this talk, I discuss results from several recent studies exploring the impact of this behavioral immune system on psychological biases toward obese individuals. Several cultural and biological factors closely link obesity with perceptions of disease. As a result, I suggest that people's behavioral immune systems activates disease-avoidance processes when confronted with obese individuals. The studies I discuss reveal such biases in three distinct psychological processes: categorization, memory, and group identification.