Differential susceptibility to social status

The diathesis-stress model focuses on the interaction between gene polymorphisms and negative environmental conditions (i.e., stressors); however, Belsky and Pluess (2009) recently proposed an alternative to diathesis-stress: the differential susceptibility hypothesis, which states that some individuals may be predisposed to be more adversely affected by negative environments but, also, to benefit more from positive environments. Nevertheless, the differential susceptibly hypothesis has not been rigorous tested. Thus, the purpose of this study was to test the differential susceptibility hypothesis by examining individual differences in men’s testosterone, behavioral, and psychological responses to social status as a function of the serotonin transporter promoter region polymorphism (5-HTTLPR), which was cited by Belsky and Pluess as a potential “plasticity gene” because one variant – the long (l) allele – appears to be associated with lower susceptibility/plasticity and another – the short allele (s) – appears to be associated with higher susceptibility/plasticity.
In this study, groups of 3-4 male participants were allowed to socialize before being told that they were part of a larger initiative to create a student-run Honor Committee. They were asked to nominate one person to be the leader and one person to not be on the committee. Then, participants were told privately that everyone voted them to either (1) be the leader or (2) not be on the committee. Salivary hormone samples were collected at baseline and 20 minutes after vote feedback. In addition, after receiving the vote feedback, participants completed a series of dating anxiety and mate preference tasks and were given the option to examine an “actual honor violation” case either alone or as part of the committee.
The results support the differential susceptibility hypothesis. In terms of testosterone response, ss individuals showed both greater reactivity and differential responses to vote feedback. Furthermore, the testosterone responses of ss individuals were moderated by basal cortisol, which is associated with approach/avoidance behavior (Kagan et al., 2003; Shoal, Giancola, & Kirillova, 2003). In addition, ss individuals’ decisions to work on the committee or work alone and responses to the mating tasks were dependent upon the vote feedback, whereas l-carriers’ decisions and responses were not.