This stuff is fascinating!

The larger a male animals testicles in relation to his

body size is a direct indication (100% predictable) of the promiscuity of the females of that

species.

Gorillas have very small testiacles for their body size. Gorilla matings are long term and are

comprised of a single, middle aged, dominant male with several females in his group, and several black back males

used as sentrys that do not mate with the females. The females are always faithful. Because any offspring of the

females in his group are always his, there is no competition for his genetic material (sperm), so he does not have

to mate very often. Male gorillas are somewhat invloved with the rearing of the young. If the silver back dies or

gets pushed out by a younger silver back, the silver back that takes over almost always kills all the infants in the

group (he doesn't want another's genes in his group).

Chimps (bonobo chimps especially) have extremely

large testicles for their body size, in fact they are much bigger than a gorillas. Females are extremely

promiscuous, in fact they perform lesbian acts as well as many couplings per day with many males. Since the males

have extreme competition for their sperm, they mate often to give their sperm the greatest chance of fertalizing an

egg. They obviously have no long term matings and the males do not participate in the rearing of the young (why

should they, they have no idea which are theirs).

This is true across the animal kingdom. It's just as true

in birds as it is in mamals.

Now lets look at humans (we are primates after all). Males have testicles that

fall somwhere in the middle as compared to chimps and gorillas. And women are also somwhere in the middle in their

promiscuity. Typically a female will look for a male that makes good money and is stable (a provider, what we

typically call a "nice guy") that she can be sure will be around to help rear her children. But she will look for

lover (a "bad boy") to impregnate her, she wants "sexy genes" so she can be sure that her male children will also

carry "sexy genes" and be more likely to find a mate themselves.

If you doubt this, in every country and

culture that has been tested so far, at minimum 10% (and more likely closer to 20%) of children are not the

offspring of the male they think is their father (yes, that means that 2 out of 10 people reading this are not

related to their father!). In some neighborhoods measured in England it's been as high as 40%. In a recent study in

the US, women that have to travel on business have 40% chance of having a "fling" while away. Even religious and

cultural pressure doesn't seem to have much effect.

This is the natural mating patern of humans for our

history (with a few aberations, like powerful rulers having harems).