Happy Ending Of The Week

It is always gratifying to read in the august pages of the Proceedings of the Royal Society B of a piece of research with a happy ending. A team of evolutionary biologists, led by Dr Matilda Brindle from University College, London, have traced the origins of masturbation to ancient primates from around forty million years ago.

While from an evolutionary perspective masturbation might seem costly, distracting, wasteful, and risky, the team sought to delve into the history of the habit by pulling together hundreds of publications, questionnaire responses and personal notes about masturbating primates from primatologists and zoo keepers. Mapping the information gleaned on to primate evolutionary trees, they were able to see how masturbation reached back through time.

Masturbation appeared common across primates of all sexes and ages, male masturbation boosting the chances of impregnating a mate by increasing their arousal before sex, meaning they inseminate their partner faster and before being interrupted by a larger rival. It also help males to shed old sperm, leaving them with fresher, more competitive sperm for sex, and, after sex, helps flush the genital tract, reducing the risk of an infection taking hold.

As for female masturbation, doing it before sex affords female primates some influence over which male gets them pregnant: by making the vagina less acidic, it becomes more hospitable to the chosen mate’s sperm.

Tissues were available when the results were revealed.