Why do men have have nipples?

In case they become trannies.

To tit-illate us.

OP, this was discussed in 10th-grade biology.

The default development is as female including with development of nipples. Then a hormonal signal is sent. If male, the formation that begins as embryos become testes, and the labia fuses to become a scrotal sac.

Because the nips are already developed by the time the hormonal shift occurs, 6 to 7 weeks into gestation. Since there's no (significant enough) evolutionary disadvantage to men having them, there was no selective pressure for them to be eliminated.

More interesting are supernumerary nipples, i.e. when you have more than two. I have three and it goes up to seven in some rare cases, which is the highest number ever observed.

R4 is correct. And I believe that’s why we all have that seam that goes down the middle of our ball sac.

I don't know about you but I'm just glad I have them. Some men can't get enough of my huge, perky nipples. And it's highly erogenous too.

Are supernumerary nipples as sensitive as the traditional two, R5? My two are hard wired to my cock and all it takes to achieve a boner is about 3 seconds of stimulation (in the right circumstances, fortunately). And yes, I can cum from nipple stimulation; it's more like an edging thing, but if I'm really horned up it can, and sometimes disappointingly, does work although I'm not Steve 'Titpig' Hurley-level by any stretch (ha!).

R4 and R5 are correct. What's interesting is what happens if those hormonal signals are not sent.

That's how you get female looking babies with X,Y chromosomes (Jamie Lee Curtis is one of them), who are infertile.

Or you can have a somewhat delayed effect - like Guevedoce where children are raised as girls, but the enzyme is released during puberty and they become 'male'. (see link)

The male and female bodies match up - nipples=nipples, clitoris=penis, labia=scrotum sack for men. It's just a matter of hormones and enzymes to determine which sex it is going to be.

There are several other (relatively rare but still common) conditions that happen when there is an interruption or something goes differently with the development in the womb.

r8 There are eight levels of completeness when it comes to supernumerary nipples, from barely noticeable to full on nipple. Mine is Type 1, which basically means that people who didn't study medicine would just perceive it as a mole. But it's a confirmed third nipple and is located on the so-called "milk line".

And I imagine a Type 8 would be as sensitive as the regular ones, yes.

You make this grey ace allo by playing with them.

R9 There is avery good book (fiction) called Middlesex that is about a Guevedoce. He was born phenotypically female due to 5-alfa reductase deficiency then became more obviously male at puberty. As is typical for a Guevedoce, he identified as male which is presumed to be due to the effects of fetal testosterone on the brain. 5-alfa reductase is necessary to convert testosterone to dihydrotestosterone. Dihydrotestosterone is necessary for normal fetal development of male genitalia and prostate.

Maybe God has a sense of humor and isn’t as uptight as the rest of us.

R6 wait a minute —what? I thought I was a seamless beauty. There’s another seam?—what’s this line going back to May ass crack?

Men have some prolactin, which gives them protective instincts towards their young. Male birds have this also (even though birds aren’t mammals, their young are helpless when hatched, just like children are). So there is possibly some evolutionary advantage to the whole structure (men develop not just nipples but actual underdeveloped mammary glands because the pituitary gland secretes prolactin; without the secretion of prolactin they might not care for their kids.) They even have a capacity to produce milk in extreme conditions- eating again after having been deprived of food to the point of starvation. That could have been helpful at some points in history for survival of offspring too. But both sexes providing milk wasn’t advantageous under most circumstances because it would lead to the baby receiving too many microbes.

R15 - that's a byproduct of having nipples - it's not the a potential reason why men have nipples. They have nipples because there's a baseline of human development for both sexes and the introduction of hormones and enzymes steer the differentiation of male or female.

The underdeveloped mammary glands are due to this unisex structure - not some evolutionary advantage.

Fathers of newborn babies can be forgiven for feeling a little hormonal – a new study has shown they are being flooded by the same chemical as a breastfeeding mother.

In the mother the hormone activates lactation. In the father it makes him a better dad.

A major University of Otago study, collaborating with international partners, has shed new light on the role of prolactin and solved the puzzle of why it is released in new fathers.

The research, which has been published in the leading journal Cell, demonstrates that prolactin directly influences male behaviour by unlocking the paternal instinct.

Conversely, if the action of the hormone is blocked, male parents will ignore their parenting duties.

Raised levels of prolactin in the blood of new fathers have previously been observed in different species.

In male human parents it rose both pre-birth and during parenting activities such as holding their child.

But until now its presence had not been understood.

Chewy McNip approves

Which famous men have tits that look like those of women?

I’ve had a President, Supreme Court Judge, fellow Senators, and many other men, nibble on my nipples. It is so titillating.

I read somewhere that men with smaller nipples tend have higher levels of testosterone. I guess this could explain why I find huge nipples unattractive on men.

I remember reading an article that said newborns tend to favor their fathers, even if they end up looking different later. Apparently, this is evolutionary so that fathers will bond with their children and not reject them. You see this in other species. If the male sets his eyes on a new female, the first thing he will do is kill her offspring, if she has recently had babies.

There was also something about males being in competition with their sons from day 1 and the goal is to get them out as quickly as possible.

So we can wear tassels.

Let's get on with more discussion and images of the scrotal sacks.

Pre-fusion or post-?

Bulls have nipples too, four of them in the majority of cases, commonly referred to as teats.

The teats are looked at when determining what he might pass on to female offspring. Bulls with three or five are typically not desirable. Also, it's supposedly preferable for the bull's teats (all four of them) to be evenly spaced, the same size, and located in front of, rather than on the neck of the scrotum.

[quote]Why do men have have nipples?

Why do you have a cunt?

So we all start out as women but some of us evolve beyond that

why do some guys have huge fabulous cocks?

Mine are hardwired to my dick. 2 guys, one sucking each nipple is Heaven. Another suck8ng my cock is even better; its happened a few times.

R28 - or men are just mutated women.

Who mutate back?