Humans are social animals, and, as such, it is to be expected that acceptance into a group would confer benefits on oneself, whereas rejection would affect one's behavior adversely. Baumeister et al. have performed a set of six experiments to identify the underlying cause of impaired behavior. In this and earlier work, the primary hypothesis has been that social exclusion leads to emotional distress, which in turn has a detrimental impact on task performance. However, in a variety of scenarios, negative mood evoked directly (via bad news) did not affect behavior, and there was no evidence for mood or self-esteem as a mediating factor for the effects of social exclusion on performance. What was observed was a lack of self-regulation, meaning that excluded individuals (in comparison to socially accepted individuals) were less able to drink a healthy but unpleasant-tasting beverage and were more likely to eat unhealthy but tasty snacks. Because the adverse effect of rejection could be ameliorated by introducing a cash incentive for performance, the authors propose that the capacity for self-regulation is intact but that a social rebuff lessens the willingness to make effortful short-term sacrifices in return for longer-term rewards (of good health or a slim physique). Looked at in another way, the consequences of rejection might be reflected at the neural level as a weight that alters the normative balance of decisions when faced with intertemporal choices. — GJC
J. Pers. Soc. Psychol. 88, 589 (2005).