cooperation shrinks your dick

The reason for these adaptations was that in the colder climates men had to co-operate in group hunting to secure food and effective hunting required a greater degree of co-operation and a reduction of inter-male sexual competitiveness and aggression than was required in equatorial latitudes, where plant and insect foods are available throughout the year, there is little need for co-operative group hunting is unnecessary, and a high level of inter-male aggression is adaptive for reproductive success. Testosterone is a determinant of aggression (Book, Starzyk, & Quinsey, 2001; Brooks & Reddon, 1996; Dabbs, 2000). Hence, a reduction of aggression and sexual competitiveness between men in the colder climates would have been achieved by a reduction of testosterone, entailing the race differences in testosterone (Negroids > Caucasoids >Mongoloids) that are given in Lynn (1990). The reduction of testosterone had the effect of reducing penis length, for which evidence is given by Widodsky and Greene (1940). http://xa.yimg.com/kq/groups/1292538/662920758/name/Examination+of+Penis+size+and+r-K+selection.pdf

some homebrew

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