What size do women prefer?

Past research suggests that women's preferences may have stimulated and determined the growth of the human penis during evolution, so that the human penis is the longest and thickest of all primates. Male genitalia evolves very quickly in the animal world, changing earlier than any other physical feature, and there is real variation in both size and shape, revealing just how much evolutionary pressure a species is under.

What type of men's private parts do women like most?

However, what puzzles scientists is what factors cause men's penises to become so large. The latest research results published in Nature magazine show that the appeal of large penises to women is gradually fading. Penis size is not a big deal for women and comes in a range of sizes, researchers told readers today.

Women consider penis size as important as height when judging a man's sexual attractiveness, but both are declining in importance as women consider masculine body shape. This has sparked renewed debate about the 1966 claim by Masters and Johnson that the vast majority of women believed penis size was unimportant. Because the results of various subsequent investigations were inconsistent and always contradictory.

The researchers, a group of biologists, used computers to generate images of men that varied their height, shoulder-to-hip ratio, and penis length. They then had 105 Australian heterosexual women view 53 life-size images of men projected onto a screen and rate their sexual attractiveness.

This latest study, which was recently conducted, shows that each trait results in an inverted U-shaped curve. Women rated taller, more masculine (meaning a larger shoulder-to-hip ratio) men with longer penises as most sexually attractive, but not without limitations, with interest in oversize declining and men who were substantially larger than average no more sexually attractive than men who were only slightly above average.

In fact, every physical sign has a ceiling effect, which means that sexual attraction has a theoretical peak. After that point, women's scores will naturally drop. The pattern the team found showed that the most sexually attractive flaccid penis length was 12.8–14.2

This idealized figure is relatively closer to the population average (9 cm) than to past surveys that predicted that women would prefer more extreme shoulder-to-hip ratios and heights, but less extreme penis sizes.