What is the most interesting fact about human behaviour?

Women moaning during sex is known as female copulatory response.

The female copulatory response is indeed an intriguing aspect of human behavior. Although it is a well-known phenomena, there is still disagreement on its evolutionary ancestry. According to some academics, it might have evolved as a means for women to indicate their readiness for sexual activity and to improve their odds of having children.

It's interesting to think that the moaning sound may perhaps presumed as old. Women have historically been required to remain mute during sex in several societies since vocalizing one's pleasure was seen immoral or humiliating. Vocalization during intercourse was, however, actively promoted in some cultures, such as ancient China and Japan, as a method to improve the experience for both partners.

Regardless of its origins, the moaning sound continues to fascinate us as a unique aspect of human sexual behavior. Some researchers have even suggested that it may serve a physiological purpose, such as increasing oxygenation or facilitating orgasm.

Source: quora.com by Kaushal Karna