There have been good points , pro and con, as to whether larger penis is likely to impregnate. But:
A direct comparison is not completely possible. Some mammals only allow the ‘dominate’ male to breed. Wolves only allow the ‘dominate’ male AND the ‘dominate’ female to breed (that’s right only the alpha couple breed).
And while chimps developed large sperm producing testes to perpetuate their genes, female chimps ‘advertise’ their fertility with over-swollen outer lips. Chimps don’t ‘couple’, they are social but they don’t ‘couple’.
So when female chimps are fertile, the males ‘have at her’ repeatedly. Huge sperm loads give the male the opportunity to fertilize, but they also attempt to guard the female after they copulate, bettering his chances, since there is no ‘commitment’.
So humans are not completely analogous with chimps. The theory is that human females developed the trait to hide their fertility to facilitate ‘coupling’ to ensure that offspring will survive since humans take so long to reach maturity and independence.
So quickly, the theory is:
1) Human men’s foreskins and glans-shape create a suction that will draw out any sperm that might have been left before him.
2) Obviously a longer penis will allow a male to deposit sperm closer to the uterus. But a thick one might create a very good suction that would draw out a previous deposit.
3) I think someone mentioned an intra-vaginal cam that a woman’s cervix ‘dips’ into a pool of sperm and sort of ‘sips’ when she climaxes? There was a scene of that happening during a female orgasm.
Whether a large penis is more likely to cause a woman to orgasm, make your own judgement. I’m not making any value judgement, I’m just reporting some of the things that I’ve read or seen in televised studies.
And as to why haven’t men developed ‘monstrous’ penises? I’d say that comparatively we have. Gorillas are much larger and have much smaller penises. We are the largest of the primates.
And why aren’t all human males ‘large’? For the same reason that there is variation in every other thing that applies to us. Some are taller, shorter, smarter, etc, etc. Anyone who is mildly knowledgeable in animal husbandry knows that there is a ‘pick of the litter’ and there are ‘runts’. (Not MY rule guys, it’s natures fact)
But also there is specific sexual selection:
A woman might choose a male who has resource riches but has a small penis. If she is faithful to him, those will be the genes that his offspring will have (barring some ‘upturn’).
The theory is that women seek men with status, because of the resources available to them. But they have a bent to cheat on the resource wealthy male if he is not also a ‘physical specimen’, so her offspring will have dominate genes.
This thread, along with the “Something I really hate” thread chronicle the duality of the objectives of men and women:
1)Women seek gentle men with resources that they can ‘nest’ with. But on a biological level, if the male is not also ‘dominate’ she many be drawn to other males.
2) Men seek women who are not promiscuous to mate with. But they also have to ‘rid themselves’ of excess sperm often (it’s not healthy to be ‘backed up’)….
Once again these are not MY rules these are NATURES rules that sociologists have observed.
There is also the observation that once a culture has the time to develop art work, they have ‘mastered’ their environment ( because they obviously have the free time). So while we are no longer in ‘survival’ mode some of our past still drives us.
More enlightened people can obviously look beyond past promiscuity in light of today’s commitment, but there is multiple-millenia of survival instincts that must be ignored to do so. And some guys aren’t capable/ willing to do it.
A quick example of our evolutionary instincts:
Women with a 7-to-10 waist -to- hip ratio, draw men’s attention. It doesn’t matter if she is 98 lbs. or 250 lbs., 4’ or 7’. She still has a biological draw, because that ratio indicates that see is a ‘breeder’. Men and women obviously choose what they are capable of ‘handling’ though.
(Here is an interesting side note: Earlier cultures valued fleshier women, because they were viewed as more fertile. And they were right, female athletes who diet to extremely low body fat do not menstruate. The fashion industry has ruined the view of what is healthy.)
And different cultures have differing views of what is alluring.
Anyway, those are the theories. Obviously time and space won’t allow me to point out all the reasons why there are exceptions to a concept/ theory/ ideology. Sorry for the length of the post.
