Effects of Socioeconomic Status and Fairness on Salivary Cortisol

Research on cooperation has contributed to a better understanding of the foundations of human social behavior. Most studies, however, have not considered fundamental social parameters such as an individual’s position in a social hierarchy. As a first step, this study investigates the modulating effects of socioeconomic status (SES) on behavior and the physiological stress response. Study participants (n = 83) played a cooperative game with computerized coplayers of four categories: similar or higher SES in combination with either high or low fairness in behavior (i.e., willingness to cooperate). All participants showed a significant increase in saliva cortisol after the game compared to a control group. Only when paired with higher SES coplayers, however, did participants show a significant subsequent decrease in cortisol concentrations. Participants’ behavior in response to a coplayer’s decisions was only affected by the degree of fairness, but not the SES, of respective coplayers. Physiologically, playing this cooperation game was a big challenge for participants as measured by salivary cortisol. Yet, the high recovery rate when playing with cooperative, higher status individuals showed the stress-protective effects of positive social interactions in the framework of social hierarchies.