Submitted by Jealous-Treat-7238 t3_zy8q5b in Jokes
In 1991, Duke University funded a study to see why the head of a man's penis was larger than the shaft. After one year and $180,000.00, they concluded that the reason the head was larger than the shaft was to give the Man more pleasure during sex. After Duke published the study, Stanford decided to do their own study. After three years of research and $250,000.00, they concluded that the reason was to give the Woman more pleasure during sex. The University of Wisconsin, unsatisfied with these findings, spent $13.27 (for a Playboy, Penthouse, and a case of Old Milwaukee) and concluded that it was to keep a man's hand from flying off and hitting him in the forehead.
kentmagyar t1_j24e82f wrote
Actually it is to remove rivals sperm from the woman, to increase your own chances of being the father.
It's also why men can not continue after ejaculation, so that they don't push out their own sperm