“…And as much recent work has shown (e.g., Twenge, Baumeister, Dewall, Ciarocco, & Bartels, 2007;Twenge and Baumeister, 2005) those who have been ostracized may become aggressive, uncooperative, or unmotivated (unlike those who have simply been threatened with social exclusion, contingent on their future behavior, like our participants). Moreover, there are a number of tangible costs to the group for using this means of social control-it can be as psychologically aversive to ostracize as it is to be ostracized (Ciarocco, Sommer, & Baumeister, 2001), monitoring compliance and excluding norm deviants can require a number of resources (potentially creating a second-order, enforcement dilemma, Kameda et al, 2003;Yamagishi, 1986). Still, the net costs to the group of using social exclusion may be far less than alternative methods of social control (e.g., fining defectors).…”