Past research has shown that women's preferences may stimulate and determine the growth of human YJ during evolution, so human YJ is the longest and thickest of all primates. In the animal world, male genitalia has evolved rapidly, and its changes occur earlier than any other physical sign. Both size and shape are truly variable, revealing how much evolutionary pressure a species has.
However, scientists are puzzled by what factors are causing men's YJ to become so large. The latest research published in the journal Nature shows that the attraction of big YJ to women is gradually fading. Researchers today told readers that YJ size is not a big deal for women, and there is still a range of sizes.
When judging a man's sexual attractiveness, women tend to equate the size and height of the YJ, but both indicators are gradually declining, believing that they are not as important as masculinity. This has led to a new round of debate about the claim made by Masters and Johnson in 1966 that the vast majority of women believe that the size of the YJ is not important. Because the subsequent various survey results are inconsistent and always contradictory.
Researchers composed of biologists used computers to generate images of men, which could change their height, shoulder to hip ratio, and YJ length, respectively. Then 105 Australian heterosexual women were asked to view 53 life-size images of men mapped onto the screen and rate their sexual attractiveness.
The latest research conducted recently shows that each feature has an inverted U-shaped curve. Women believe that men who are taller, have more masculine characteristics (meaning a larger shoulder to hip ratio), and have a longer YJ are the most sexually attractive, but there are also restrictions. Interest in oversize has declined, and men who are substantially larger than the average are not more sexually attractive than men who are only slightly above the average.
In fact, every sign has a ceiling effect, which means that there is a theoretical peak in sexual attraction. After that point, women's ratings naturally decline. The pattern investigated by this team indicates that the most sexually attractive weak state has a YJ length of 12.8 – 14.2 centimeters, which is an idealized figure that is relatively closer to the average figure for the entire population (9 centimeters), rather than closer to the past type of survey prediction. Women who prefer a more extreme shoulder to hip ratio and height are less prone to an extreme YJ size.