Dr Diana Fleischman New research says “homosexual behaviour” may have evolved to promote social bonding in humans. Dr Diana Fleischman and colleagues from the University of Portsmouth examined the relationship between progesterone and sexual attitudes to explore the role that homosexual behaviour may have played in cementing alliances over the course of human evolution. Their research is published in the journal Archives of Sexual Behavior. They found that straight women who have higher levels of progesterone are more likely to be open to the idea of engaging in sexual behaviour with other women. Similarly, when heterosexual men are subtly reminded of the importance of having male friends and allies, they report more positive attitudes toward engaging in sexual behaviour with other men. This pattern is particularly dramatic in men who have high levels of progesterone. The hormone progesterone is known to contribute to the formation of social bonds, which have many adaptive benefits for humans. The hormone is produced mainly in the ovaries in women and in the adrenal glands in men. It is one of the main hormones responsible for caring or friendly behaviour and levels rise when people have close and friendly interactions. Women’s levels of progesterone peak after ovulation when the chance of becoming pregnant is dramatically reduced. Dr Fleischman said: “From an evolutionary perspective we tend to think of sexual behaviour as a means to an end for reproduction. However, because sexual behaviour is intimate and pleasurable, it is also used in many species, including non-human primates, to help form and maintain social bonds. We can all see this in romantic couples who bond by engaging in sexual behaviour even when reproduction is not possible. “The results of our study are compelling because using two very different methods, they arrived at the same conclusion. Women were more likely to be motivated to think about homosexual sex when their levels of progesterone were higher. Compared to a control group, men’s homoerotic motivation was not increased by priming them with sex but thinking about friendship and bonding caused a measurable change in their attitude to the idea of having sex with other men.” Read more here and check out the video below University of Portsmouth, GayNZ.com staff - 27th November 2014
Credit: University of Portsmouth, GayNZ.com staff
First published: Thursday, 27th November 2014 - 12:21pm