Physical competition increases testosterone among Amazonian forager-horticulturalists: a test of the ‘challenge hypothesis’

Trumble BC, Cummings D, von Rueden C, O'Connor KA, Smith EA, Gurven M, Kaplan H (2012). Physical competition increases testosterone among Amazonian forager-horticulturalists: a test of the ‘challenge hypothesis’. Proceedings of the Royal Society B: Biological Sciences.