Why has the male penis developed into an appendage longer and thicker than that of any other primate?

Maybe it’s because women prefer them bigger?

An Australian study to be published in the “Proceedings of the National Academy of Sciences” finds that penis size is one aspect that determines a man’s appeal to the opposite sex.

One hundred and five heterosexual women rated their levels of attractiveness to varying life-size images of naked male figures. The composite images differed in height, penis size, and shoulder-to-hip ratio. The bulk of the women found taller men with broad shoulders, narrower hips, and a longer penis to be most desirable, however the results showed a sharp decrease in attractiveness when the traits were extreme.

Women found a flaccid penis of approximately 5 to 5.5 inches to be most attractive (the study states just over 3.5 inches is average). The ideal length penis selected by women was closer to the average than the perceived ideal height or hip-to-waist ratio of mates.

Study authors believe this shows women prefer more extremes in height and hip-to-waist ratio than they do in penis size.

Researchers are hopeful these findings will lead to a better understanding the evolutionary development of the human male penis which has developed into an appendage longer and thicker than the penis of any other primate.