An economic analysis of apathetic behavior: Theory and experiment

This looks worth reading.But I can't be bothered.

Aiko Shibataa, Toru Morib, Makoto Okamurac and Noriko Soyamad
Journal of Socio-Economics
Volume 37, Issue 1, February 2008, Pages 90-107

Abstract
The apathy of bystanders often prevails when instances of bullying, hidden crime and extortion occur in communities such as schools, business work areas, underclass ghettos, prisons and the military. The present study models apathetic behavior as a non-cooperative game and attempts to verify this theory through experiments. Furthermore, our research suggests that the apathy of bystanders generally decrease as the number of citizens in a community decrease. In our experimental cases, if the number of members in a group decreases from 40 members to 20 members, the concerned and helpful behavior of bystanders increases by 21%.