Vugt, M. van

group competition women experiment group identi fication condition gender effect psychology university cooperation fication group condition participant identi hypothesis contribution result difference member male-warrior hypothesis research behavior cremer student male-warrior threat history procedure error science warfare error bars van vugt trial study journal dirk p step-level public-goods game bulletin mediation southampton brewer volume 18— number public-good interaction personality london analysis quali fied fi ndings literature instruction contribution level insko team sports gender differences sacri fice pence panel implication nding review design level group member .99. group contributions human scientist schopler suicide terrorism step-level public-goods task tooby sds 5 1.54 turner flicts gang rivalries pemberton