Why do men like "plump and thin" women?

Most men like women with big breasts, wide buttocks and thin waists. Some people analyze it from a cultural perspective and believe that this is just a fashion. One piece of evidence they cite is that people have different aesthetic standards in different eras and societies. Some people explain it from a biological perspective, believing that the larger a woman's hips are relative to her waist, the more advantageous it is for her to give birth, and that the larger her breasts are, the more milk she can secrete.

Grazyna Jasinska of Harvard University in the United States and her colleagues recently proposed a new view on this phenomenon, believing that this is simply because women with big breasts, big buttocks and thin waists are more fertile. They found that there was a significant correlation between the levels of two fertility-related hormones and body shape in women of childbearing age. Their research report was published in the latest issue of the British Journal of the Royal Society.

The researchers collected data on body measurements and other aspects of their lives from 119 women aged 24 to 37, and took saliva samples from them to observe how they changed over a menstrual cycle. The researchers then divided the saliva samples into four types: the type associated with a small waist and large hips, the type associated with a small waist and small hips, the type associated with smaller breasts, and the type associated with larger breasts. The researchers carefully analyzed the levels of two hormones in the saliva of the four groups of subjects: progesterone and 17-b-estradiol, both of which are known to be related to female fertility.

The researchers found that both types of women with thin waists had high levels of the hormone progesterone, but when it came to the hormone 17-b-estradiol, those with thin waists and large breasts had the highest levels of the hormone — especially around the time of their ovulation. Because levels are so high, Jacinska estimates that these women are three times more likely to conceive under any circumstances than women of other body types. From an evolutionary perspective, this means that women with thin waists, especially those with big breasts, thick buttocks and thin waists, will become the most desirable partners for men.

However, it was not clear how women's physical characteristics reflected their hormone levels, which is what the researchers plan to study next.