doublelongdaddy said:
That would have to be a drug that effects the libido and I am under the assumption that there is nothing to increase libido.
There is a hormone men produce that makes us not interested in sex after we cum. It can be overwhelmed by high libido, however usualy as men ejaculate their desire goes down for some time.
Women don't produce that hormone, thats why when women are in heat they could fuck all day long. Also why women can have multiple orgasms. Of course the trade off for women is that they only have huge desire for a few days a month.
Men are more constant in their desire. However at their peak women's sex drive surpasses men's by a fair ways. I'm sure you guys have seen this when women are really ready to get pregnant, they will shove anything in their pussy and want multiple men to screw them.
One reason men do this is so that later on they can go and cum in another woman. Hence possibly get two women pregnant. Or more. If they 'wasted' all their sexual energy on one woman it would limit their chances of passing on their genes.
The nature of women's ovulatory cycle means that they need to get a lot of sperm in them during the days when they are the most fertile. Remember ancient man also wasn't sexualy active all year. Studies of neanderthals show that they had periods of starvation, followed by plenty. Want to kill your sex drive? Be freezing cold and starving.
Want to crank your woman's sex drive up? Make sure she gets tons of fats and energy. It takes 30,000 calories just that the baby consumes in the 9 months of growing. Then a huge amount more in the nursing afterwards.
So women would only go into heat rarely. Like once every few years sometimes. During that time they want to get nailed by as many men as possible.
In times of plenty which were rare the man also wanted to nail as many different women as possible. If he had no refractory period he would likely keep screwing one woman. Which would severly limit his genetic imprint in future generations. Hence why the refractory period evolved in most male species.