This theory again attempts to explain why women are more interested in same-sex acts than men
Women have been known to be more sexually fluid than men, but no one had a solid theory for why that is – until now.
According to the journal, Biological Reviews, sexual fluidity may be a result of evolutionary design.
The lead author of the study and evolutionary psychologist, Dr. Satoshi Kanazawa, proposes that sexual fluidity arose in women as a mechanism for reducing conflict and tension among co-wives in polygynous marriages.
Being sexually fluid would have allowed women to have sex with their co-wives while still successfully reproducing with husband.
The theory suggests that women may not have sexual orientations in the same sense as men do. Rather than being straight or gay, to whom women are sexually attracted may depend largely on the particular partner, their reproductive status, and other circumstances.”
The researcher says this suggests that women’s sexual fluidity may have been evolutionarily selected as one method for facilitating polygynous marriages, in which a husband can have more than one wife.
Even though humans have been mildly polygynous throughout evolutionary history, polygynous marriages are often characterised by conflict and tension among co-wives. I propose that occasional sex among co-wives may have reduced such conflict and tension, and increased their reproductive success. Female sexual fluidity may have evolved as an adaptation to facilitate it.”
Sexual fluidity may have arisen to help women establish bonds and key alliances in their new group, where they were surrounded by strangers.
Since friendships and alliances can have reproductive benefits, sexual fluidity that facilitates such friendships and alliances among women is expected to be evolutionary selected.”
According to Kanazawa, this theory may also help explain many other puzzles in human sexuality, including male arousal to lesbian sex, and menstrual synchrony, in which the menstrual cycles of female companions align over time.