Brask, J B, Croft, D P, Edenbrow, M, James, R, Bleakley, B H, Ramnarine, I W, Heathcote, R J P, Tyler, C R, Hamilton, P B, Dabelsteen, T & Darden, S K 2019, ' Evolution of non-kin cooperation : social assortment by cooperative phenotype in guppies ', Royal Society Open Science, vol. 6, no. 1, 181493 . https://doi.org/10.1098/rsos.181493 Royal Society Open Science Royal Society Open Science, Vol 6, Iss 1 (2019)