They also may have worked out from this when they were fertile and when they weren't and have worked out the best time when they would allow men to ejaculate inside them, to have children. This would mean that men who having been trained to withhold ejection, when given the chance to ejaculate inside a woman would probably orgasm very quickly. This is because the women would be more interested in conceiving than sexual pleasure, when she wanted to conceive. So the man would want to ejaculate quickly in case she might change her mind. This certainly would be a consideration in a society where there is no marriage, and if he took too long she might get bored and frustrated and terminate the sex-act. She would then be at liberty to use another sex partner who wouldn’t take too long.
In many patriarchal cultures, even today, the clitorises of young women are removed. Perhaps the original reason for this is the knowledge that sexually active women are dominant woman. So men attempted to make women more submissive by removing their clitorises. This suggests knowledge when this practice was first started off in the ancient past of very sexually active women being also dominant women.
Matriarchal rule it seems not only has changed women physically but has also changed men. Humans have evolved from ape-like creatures and today apes are our closest relations. One of the things that make us different from the apes is that men have far larger penises than any other male ape. In fact a male gorilla, which are larger than us, has a penis about the size of our small finger. Now in evolutionary terms a large penis doesn't make sense, because it doesn't require a large penis for a man to fertilize a woman. Today sexologists tell us that, "size doesn't matter", and that is true physically, because a man is just as able to bring a woman to orgasm with a small penis than with a far larger one. This is because it is mostly the clitoris that gives women sexual pleasure, and not the inside of the vagina. So why did men evolve far larger penises than apes?
A clue to this can be seen in birds like peacocks and birds of paradise. The male bird in these two species has developed extraordinary, very large and very colourful feathers. It seems that the evolutionary pressure for male birds to develop these feathers come from the female bird, who pick which male she wants to mate with. It seems that the female bird picks her mate on the basis of who has the most colourful feathers and so over evolutionary time the most successful male birds in mating, has been those who are the most colourful. Even in spite of the fact that these large colourful feathers can be a hindrance in flying and make it easier for a predator to see them.
In the human species although it is true physically that, "size doesn't matter" in sex and reproduction. It does seem to matter a lot with women visually. In recent years with women admitting to like viewing naked men, what seems to be the biggest turn-on is men with very large penises. If this was true in our Matriarchal past it means that men with large penises would be the ones to be picked by women for their sex partners, and would therefore father far more children than men with smaller penises. Creating a evolutionary pressure where men with large penises will be the most likely to breed
This suggests that perhaps male nudity was commonplace in matriarchal societies. It also may be the reason why most patriarchal societies make laws about people wearing clothes even in hot countries. These laws may of come originally from knowledge of our Matriarchal past where men were chosen on the basis of their penis size. It seems that this used to be true up to recent times in some New Guinea tribes where men didn’t wear loincloths and it seems that men’s status in the tribe did depend on the size of his penis. To the degree some men tied weights to their penis to stretch them to make them longer. Or they would put a bamboo over their penis to make them look bigger.
This is reflected in our modern world where men can buy vacuum pumps that fit over the penis to try and increase their size. On the Internet now there are web sites that sell herbs and penis exercises that also suppose to make men’s penises larger.
Dildo found in Stone Age excavation in Sweden
So if men’s status in a Matriarchal society depended on the size of his penis, a cover-up was called for in a patriarchal world, so people will forget this custom and the Matriarchal world that created it. In theory in a patriarchal society penis size shouldn't matter to men, because if men are the dominant sex, then whether women find them sexually attractive or not shouldn't matter. Yet even after about four or five thousand years of patriarchal rule men with small penises still envy men with larger ones. This suggests that the ancient instinct in men to want to be chosen by women for their sexual pleasure, is still very strong within them.
Desmond Morris in his book "The Naked Ape", suggested that the reason why women have breasts is because men have chosen women with large breasts to mate with. The theory being that when we moved about on all four limbs, it was women's behinds that men fixed on as being sexually attractive, because then men only had sex from the rear with women. Then when human beings stood upright, people began to have sex face to face. As men still was focused on women's buttocks as a sexual stimulant, women with a fleshy breasts similar to a woman's bottom would be more sexually attractive to men, than women with a more flat chest. This then, would suggest that not only women had the power of choice in the stone-age but men also. So does this mean that the large breasts of women and the large penises of men mean that the sexes were equal during the Stone Age? This would be unlikely because, as I have previously pointed out, the difficulty of women and men find today in having equal sex.
But Desmond Morris breast theory is not the only theory why women have large breast the Aquatic ape theory also has an explanation for this.
Update. Research on women does show they prefer men with larger penises. http://sciencealert.com.au/news/20130904-24241.html