Originally Posted by River
... that women just aren't well suited for polyamory, that it goes against a woman's basic nature when there is sexual/romantic involvement. He said he thinks women are just biologically driven to be possessive and desire exclusivity in love.
I would say to Sean that he needs to stop reading those "popular evolutionary psychology" books by Desmond Morris and co. This to me smells very much like the argument for "philandering men and clingy women". In case somebody hasn't heard it a thousand times already, this pet theory of certain (mostly male) scientists goes like this:
1) Pre-historic Earth is a tough place where men hunt big game and women hang in the homey caves, cradling babies and being highly vulnerable to predators, other males and incapable of finding nutrition on their own, because they are practically invalids for the duration of pregnancy and breast-feeding, which is also pretty much the only thing they do.
2) Big tough men have something called "selfish genes". The genes want to spread as far as possible. They have, like, gadzillion spermatoids ready to impregnate any woman they can successfully land on.
3) Women's selfish genes, however, have interests directly in opposition to that. Because of their general uselessness, women need men to bring home the big game to feed them and their babies. Of course, one man can only feed one family at a time. So women compete amongst themselves in trying to secure the economic services and manpower of "their" man, promising sexual fidelity and unlimited sexual access in turn. Men are not exactly happy with this, but they take the risk of providing for a child not necessarily their own because they really need somebody to cook for them and a male heir to inherit, well, their stuff. While men police their women's sexual behaviour, they philander themselves to ensure that despite this unhappy compromise, their genes have a fair chance of spreading and their offspring being conveniently raised by some unsuspecting cuckold.
So shockingly, this "scientific" explanation of pre-historic mating behaviours that have supposedly survived to this day becomes the mirror image of the 50's white middle-class America. This is also the theory behind the commonly asserted assumption that men are more troubled by the idea of their women sleeping with someone else and women more troubled by the idea of their man falling for someone else (and thus removing his precious economic contribution to the family in favour of someone else).
There are gaping holes in this theory. Actually, big game hunting has never been such an important part of pre-historic hunter-gatherers' diet as these caveman visions would imply. Their diet has mostly consisted of foraging, trap-setting and small-scale primitive agriculture, meat used mostly for ceremonial purposes. Studies of surviving hunter-gatherer cultures show that foraging for food takes a much smaller part of the day than the average day job of the modern world, and leaves plenty of free time. Also, societies like that don't organize along the one man-one woman-their kids-principle, and food and other resources are divided communally, not inside nuclear family units.
Moreover, pre-historic milieus could only support human communities of 100-150 people at maximum at a time, so in times of excess food and declining child mortality, fertility needed to be controlled through taboos, gender segregation, institutionalized homosexuality and abortions/abandoning of newborns. Actually, it seems that for whatever reason, it is men who biologically programme females to bond with them and their offspring. Sperm contains oxytocin which encourages bonding and works against depression (presumably also post-partum depression).