“…Recent papers in economics include Shupp and Williams (2008), Baker, Laury and Williams (2008) and Masclet, Colombier, Denant-Boemont and Loheac (2009). Groups' attitudes towards cooperation and reciprocity were first examined in the context of prisoner's dilemma games: see Pylyshyn, Agnew and Illingworth (1966), Wolosin, Sherman and Maynatt (1975), Lindskold, McElwain and Wayner (1977), Rabbie (1982), Insko, Schopler, Hoyle, Dardis and Graetz (1990), and Schopler and Insko (1992). Wildschut, Pinter, Vevea, Insko and Schopler (2003) provide a meta-analysis of the subject, while Charness, Rigotti and Rustichini (2007) is a more recent contribution in economics.…”