"a public good is the human equivalent of a peacock's tail"

http://www.ncbi.nlm.nih.gov/pubmed/23320439

Br J Psychol. 2013 Feb;104(1):3-13. doi: 10.1111/j.2044-8295.2011.02093.x. Epub 2012 Feb 1.

Men behaving nicely: Public goods as peacock tails.

Van Vugt M, Iredale W.

Source

Department of Social and Organizational Psychology, Faculty of Psychology and Education, VU University Amsterdam, The Netherlands Institute for Cognitive and Evolutionary Anthropology, University of Oxford, UK Centre for the Study of Group Processes, University of Kent, Canterbury, UK Department of Psychology Sociology and Politics, Faculty of Development and Society, Sheffield Hallam University, Sheffield, UK.

Abstract

Insights from sexual selection and costly signalling theory suggest that competition for females underlies men's public good contributions. We conducted two public good experiments to test this hypothesis. First, we found that men contributed more in the presence of an opposite sex audience, but there was no parallel effect for the women. In addition, men's public good contributions went up as they rated the female observer more attractive. In the second experiment, all male groups played a five round public good game and their contributions significantly increased over time with a female audience only. In this condition men also volunteered more time for various charitable causes. These findings support the idea that men compete with each other by creating public goods to impress women. Thus, a public good is the human equivalent of a peacock's tail.