@article {650971,
	title = {Group cooperation without group selection: Modest punishment can recruit much cooperation.},
	journal = {PLoS One},
	volume = {10},
	year = {2015},
	pages = {e0124561},
	author = {Krasnow, M. M. and Delton, A. W. and Cosmides, L. and Tooby, J.}
}
