From an evolutionary perspective, why do women have bosoms?

[physicsdude30]

We've all heard people from time to time in their conversations ask about this riddle. Many say that they're all fat and don't know why men care about them, etc.


This is what some think evolution says, plus some alternative views. I like to test ideas. What's everyone's take on this? :

There is no relationship with bosom size/shape and the amount of baby milk one can produce, and the other primates don't have permanent bosoms like humans do. However, there's a relationship between sexual maturity and size/form (too old and they're not shaped as well and too young, you get the point). Because of this, many zoologists and evolutionary psychologists think they evolved out of sexual selection, just like a male peacock's feathers get in his way but say to the females, "Come here good looking!"

On the other side of the coin, some opponents to sexual selection point out there's no relationship between bosom size and how likely a woman is to get married. They say that if it's sexual selection, then you'd expect it would give a woman an advantage in obtaining a mate. They say most of the time sexual selection is actually in the males in the animal kingdom, since most females who live long enough will mate, while quite a few of the males never get to score (mammals and birds). They also point out how the majority of human females who live long enough find some kind of partner.


So what's your opinion so far? Any insights? Since bosoms are just fat and many social conversations are curious about the answer to this riddle, why do men like them, and why do women have them? Keep in mind there's no relationship between size/milk potential, and also getting married, and the other primates only have them when nursing rather than permanently.


So, what if we were to go at this question from a different angle? I have an idea of my own and a way to make it scientifically falsifiable. I need some feedback here. Here goes ... Women tend to look for men with nice cars and lots of diamonds! Just kidding! I meant there's some interest in resources there. What if it's possible that there was a population bottleneck in the course of human history, some think there was? What if during times of famine having a male partner who had lots of resources had an evolutionary advantage for the woman and her kids? Maybe we could say "Women have permanent bosoms unlike other primates because they gave a distinct sexual selection advantage during times of severe famine because they could get the men with the better resources" rather than just sexual selection, since most who make it to the right age find a mate anyway?

Just like someone tests their car/sink after fixing it, maybe we could test our theory? Any ideas? I think probably the easiest way to make it possible to be falsified would be to see if there's a relationship between bosom shape/size and how much money a woman's husband earns? Yes, I know you couldn't go around doing that. However, just like scientists say there's no relationship between size and milk, maybe those in the "medical field" who handle that could be bribed with research money into testing our idea by doing an extensive survey where they find out how much their patients' husbands make? Although correlation doesn't prove causation, we could control for as many third variables that seem reasonable, and see if there's still the relationship. Although we can't prove, do you think that would make it falsifiable and count as a logical consequence? I was also brainstorming the possibility of looking at genes responsible for permanent bosoms and seeing if the estimation for these certain genes evolving coincide with certain bottleneck/widespread famine dates scientists may be aware of.

Enough about my thoughts, what does everyone else here think about our hypothesis? Any other ideas on why men are attracted to them and why women have them?

 

[junglebeast]

The male has evolved to find the female form arousing to encourage reproduction. The female form evolved to have wide hips for child bearing and larger breasts (than males) for lactating. In response, males evolved an attraction towards larger breasts and wider hips. This then created a selective pressure for women to have even wider hips and larger breasts.

 

[Loren Booda]

Why do men have nipples?

 

[Evo]

The male has evolved to find the female form arousing to encourage reproduction. The female form evolved to have wide hips for child bearing and larger breasts (than males) for lactating. In response, males evolved an attraction towards larger breasts and wider hips. This then created a selective pressure for women to have even wider hips and larger breasts.

So why do most men prefer small hips and butts?

 

[rootX]

women with small boobs are usually unattractive.

 

[humanino]

women with small boobs are usually unattractive.

Did it occur to you that it might be related to the probability for them to feel unconfident ?

So why do most men prefer small hips and butts?

Which men ? There are certainly places where this is not a true statement. For instance, Europe middle ages. Maybe our current societies placed a high value a while ago to taking care of one's own health, for instance not allowing oneself to become too fat. As time goes, some men may associate thin women with healthy women, or at least women who have enough free time to take care of themselves and exercise. I do not claim this is a true correlation, I claim it is possible that some men make the correlation in their head, possibly unconsciously.

 

[TheStatutoryApe]

The male has evolved to find the female form arousing to encourage reproduction. The female form evolved to have wide hips for child bearing and larger breasts (than males) for lactating. In response, males evolved an attraction towards larger breasts and wider hips. This then created a selective pressure for women to have even wider hips and larger breasts.

This, pretty much. Larger fuller breasts are a sign of health and fitness. Women who have aged(younger women are less likely to have fertility issues), suffered disease, ill health, or lack of nutrition will likely have withered breasts. While small breasts may not necessarily be any indication of lacking health or fitness neither do they indicate any greater health or fitness so they would be less likely to be selected for.

 

[humanino]

This, pretty much. Larger fuller breasts are a sign of health and fitness. Women who have aged(younger women are less likely to have fertility issues), suffered disease, ill health, or lack of nutrition will likely have withered breasts. While small breasts may not necessarily be any indication of lacking health or fitness neither do they indicate any greater health or fitness so they would be less likely to be selected for.

I have heard of a more specific theory. When we were not standing yet, we were attracted by what we now could call "bottoms". The size of the female breasts developed (according to this theory) after we began to stand up. I unfortunately do not recall any reference, and I can not remember how credible this argument was. Maybe they did have bone quantitative indication to support this idea.

 

[waht]

Many women complain that having big boobs hurts their chest, and lower back. Some have even undertaken a breast reduction surgeries.

 

[TheStatutoryApe]

So why do most men prefer small hips and butts?

I think women prefer small hips and butts. There have even been studies that show men prefer a lower waist to hip ratio.

Edit: And if you look at most mens magazine covers you will see the evidence.

 

[fourier jr]

I have heard of a more specific theory. When we were not standing yet, we were attracted by what we now could call "bottoms". The size of the female breasts developed (according to this theory) after we began to stand up. I unfortunately do not recall any reference, and I can not remember how credible this argument was. Maybe they did have bone quantitative indication to support this idea.

desmond morris wrote about that. i don't know if he was the first to point that out or what

 

[junglebeast]

So why do most men prefer small hips and butts?

Men still prefer large hips and butts relative to size of hips and butts of other males. You are using the word "small" in reference to the average modern women, which is much more overweight than what we would have evolved an attraction for.

It is no surprise that when you take the ideal biological woman and replace her active lifestyle with a sedentary one, and make food a commodity that even the poorest person can afford in abundance, their resulting body shape is no longer the same as in the history of evolution.

 

[WhoWee]

I think men like large bosoms because they're more noticeable - they stick out and men look at them. It could be that simple. Men react more to visual stimuli than women.

As for small hips and butts (how shall I phrase this), the perfect female form (for many men) is the one with the "natural spread" as it's called. That is, when a woman stands with her legs straight and together at the knees, you can see between her thighs (from the front or rear) to the other side - just below her private areas. This is the aspect of "wider hips" that men may cite.

On the other hand, if the female is full figured, it is not apparent. At that point, a different set of criteria is appreciated.

 

[GeorginaS]

women with small boobs are usually unattractive.

Care to back-up that needlessly insulting commentary?

 

[aPhilosopher]

women with small boobs are usually unattractive.

I'm generally more attracted to smaller breasted women. It just gets to a point with the big ones where it's like enough is enough already.

 

[Evo]

I'm thinking of models and actresses, they all have no hips or butt, if they do, like Jennifer Love Hewitt, they are ridiculed.

I have no hips or butt and men love it. Yes you can see between my legs because they are so thin. Nothing to do with the width of my hips. And I have large breasts.

 

[Loren Booda]

In "The Best Songs Ever" thread there is a rap video (by Drake - Best I Ever Had) smothered in big, bouncing breasts. Too much!

 

[humanino]

I have no hips or butt and men love it. Yes you can see between my legs because they are so thin. Nothing to do with the width of my hips. And I have large breasts.

I'd like to say "maybe you have for some reason not met the men who are not attracted by the features you describe" but for some reason, after what you've just said I agree with you anyway

 

[Cyrus]

I can tell you for a fact that women with bigger breasts get more tips (including from me) at the strip club. Survival of the fittest.

 

[Proton Soup]

I think women prefer small hips and butts. There have even been studies that show men prefer a lower waist to hip ratio.

Edit: And if you look at most mens magazine covers you will see the evidence.

yeah, i am an *** man, and i just don't get this small butt thing. i think it's mostly a neurosis. some of it is hollywood- and other celebrity-driven. women tend to have excellent shape when they are young, fertile, and in excellent physical and hormonal condition. that can make for a short career as a sex-symbol. they get older and their boobs deflate and sag. they can do a lot of exercise now and bring the hips/thighs down, but this then requires a boob job to complete the look. they may not even have hips now because they're older, the hormonal situation is worse, and fat stores in other places that have to be slimmed down. so small butt, and big fake boobs.

then there are other things. fewer women breastfeed now. breastfeeding has interesting effect: it pulls fat off the thighs.

some also blame media types like Hugh Heffner for promoting more masculine female types, and claim that the women in his magazine have more masculine features now than in its early days. as further evidence, they observe that Heffner has now admitted that he has experimented with bisexuality. maybe that's an age-related thing, it certainly seems to happen to congressmen often enough.

evolutionarily, i find the mimicry of the buttocks interesting. but more than that, it takes a lot of time and energy to raise up healthy human children. the breast makes a convenient place to store up extra reserves for lean times, and it's in a convenient place for the male to observe and make a mate selection. spread out across the body, it would be less obvious.

 

[Quincy]

So why do most men prefer small hips and butts?

Which planet do you live on?

 

[TheStatutoryApe]

I'm thinking of models and actresses, they all have no hips or butt, if they do, like Jennifer Love Hewitt, they are ridiculed.

By whom? I usually hear men complain about women not having any butt or hips. I mostly hear women making nasty comments about women with big butts and wide hips. Perhaps men around you say they do not like butts and wide hips because you are particularly lacking in these attributes?

I have no hips or butt and men love it. Yes you can see between my legs because they are so thin. Nothing to do with the width of my hips. And I have large breasts.

Most men it seems are more preoccupied with breasts than hips and butts. Men also like thinner women. The preferred waist to hip ratio is supposedly 0.7 which means a woman must be at least somewhat thin to fit the preference. So a woman who is both thin and has large breasts is probably more than acceptable to most.

If you look though you will find that there is a massive market share for men who like butts.
Also for actresses with hips and butts...

Jennifer Lopez
Eva Mendez
Angelina Jolie
Halle Berry
Rosario Dawson
Rose McGowan
Jennifer Tilly
Minni Driver
ect ect

And if you look at models that are predominantly in magazines and such for men many of the more famous ones have some wide hips and round bottoms.

 

[Moonbear]

So why do most men prefer small hips and butts?

Define most. I've never met any who like small hips and butts. I have, though, met many women under this bizarre delusion that they need small hips and butts...maybe it's a rumor spread by women to eliminate some of the competition by putting them under pressure to do exactly the opposite of what will attract men?

Models don't have big butts, not because that's attractive to men, but because it's easier to drape clothing over them without having to worry about fitting curves. It's purely an advantage for displaying clothing on a walking hanger, without people focusing on the woman wearing them. You're supposed to be looking at the clothes, not the model.

As for breast size, without "enhancements," USUALLY breast size corresponds fairly well to the amount of body fat one has. Someone very thin and petite usually has smaller breasts, someone more rotund has larger breasts. Miracle bras and implants make it harder to make this distinction. Yes, there are very thin women who will still have larger breasts, but they are not all that common, making it hard to believe there really has been any great selection pressure for that body type.

 

[Nan]

The only evolution here is that of social acceptance and that of what the perception is of 'healthy' and beautiful. Anyone remember "Twiggy"? Before that, women were more curvaceous and a lot larger in sizes, it was more fashionable. Before that we had the 'flappers' of the '20s and 30s who deliberately flattened their breasts. Before that women who had bellies and hips clearly identified in art of the ages, were more desirable.

There is really no utility here from an evolutionary standpoint, its merely the cycles that are man-created. As women are able to reproduce later in life successfully, (and can do so without actual mating) the qualities that identified a women as a good candidate for successful reproduction becomes less important. The appearance of a woman and what is desirable for a male is now completely esoteric, with individual taste becoming very broad and less uniform.

Women get confused messages and some go to extreme lengths to make themselves desirable in appearance based on the popular culture of the day.

Aging happens, increasingly its a multi-billion dollar enterprise to foil it. Those who remain 'natural' then appear 'unnatural' and less acceptable socially. So augmentations done surgically for noses, breasts, face lifts, etc. are more common extending out into those beyond those in the public eye. Girls become obsessed about their outward appearance, also resorting to surgery to fix noses they don't like or augment a body part before they are even mature.

Personally, I think it is sad.

 

[Blenton]

I think its sad to for somebody to think that attraction is a byproduct of society. You can't teach someone to be attracted to specific features.

 

[billiards]

The male has evolved to find the female form arousing to encourage reproduction. The female form evolved to have wide hips for child bearing and larger breasts (than males) for lactating. In response, males evolved an attraction towards larger breasts and wider hips. This then created a selective pressure for women to have even wider hips and larger breasts.

But OP said larger breasts don't increase milk production, which if correct significantly weakens this argument (in my opinion).

So why do most men prefer small hips and butts?

Most men prefer a curvaceous woman within limits. Certainly, a woman "with hips" is more attractive to me than a woman with a more masculine hip to waist ratio ( that tends towards unity).

 

[TheStatutoryApe]

The only evolution here is that of social acceptance and that of what the perception is of 'healthy' and beautiful.

You're talking about now. What is going on now has no bearing on what happened during human evolution to select for breasts larger than utility requires.

 

[Astronuc]

I think its sad to for somebody to think that attraction is a byproduct of society. You can't teach someone to be attracted to specific features.

Attractiveness is a function of culture (behavior), which develops in any society. I think most fashion models look ill and unhealthy.

Breast size is a complicated function of genetics, hormones, diet and pregnancy. It's not just fat, but there are milk secreting glands and delivery system (ducts).

Also keep in mind that breast cancer affects about 12% of the female population (or 1 in 8), which seems to have increase from about 1 in 20 or about 5% of the female population two or more decades ago. The earlier statistics are not too reliable because it might be the women were not properly diagnosed more than 2 decades ago.

It is silly or sad that so much effort/resources/energy is wasted on superficial external appearances. What counts is what is inside a person - the mind and personality - as well as the healthiness.

There seems to be an awful lot of fuss over nothing more than mammary glands of which the primary function is to provide food to offspring until they develop the capacity to digest other foods.

As for evolution, I believe monkeys and apes have 2 breasts, but usually not as voluminous as human female breats.

 

[Nan]

You're talking about now. What is going on now has no bearing on what happened during human evolution to select for breasts larger than utility requires.

Look at ancient art! Look at "less sophisticated' indigenous populations sheltered from media! Those women's breasts are smaller, look more like other mammals particularly after giving birth a few times.

 

[Loren Booda]

Remember the prehistoric "Venus" statues http://en.wikipedia.org/wiki/Venus_figurines" .

 

[Nan]

lol! From the link provided:

The question of the steatopygia of some of the figurines has led to numerous controversies. The issue was first raised by Édouard Piette, excavator of the Brassempouy figure and of several other examples from the Pyrenees. Some authors saw this feature as the depiction of an actual physical property, resembling the Khoisan tribe of southern Africa, while others interpreted it as a symbol of fertility and abundance. It must be noted in this context, that not all Palaeolithic female figurines are rotund or have exaggerated feminine features. Also, not all are devoid of facial features.

The Venus of Willendorf and the Venus of Laussel bear traces of having been externally covered in red ochre. The significance of this is not clear, but is normally assumed to be religious or ritual in nature—perhaps symbolic of the blood of menstruation or childbirth.

All generally accepted Paleolithic female figurines are from the Upper Palaeolithic. Although they were originally mostly considered Aurignacian, the majority is now associated with the Gravettian and Solutrean. In these periods, the more rotund figurines are predominant. During the Magdalenian, the forms become finer with more detail; conventional stylization also develops.

 

[junglebeast]

But OP said larger breasts don't increase milk production, which if correct significantly weakens this argument (in my opinion).

That statement may be roughly true in general but I haven't seen convincing proof that a girl that is completely flat chested (no boobs at all) can produce just as much milk as a busty girl. I find that to be a dubious claim, as breastmilk is produced in the breast.

Regardless, the breasts will become enlarged during breast feeding, which is all that is required to make enlarged breasts a characteristic sign of femininity, especially when ancient women were talking around topless with suckling children all the time.

Further, it makes a distinction between fertile women and infertile women, because a girl with lactating breasts has already had a baby, showing that she is capable of giving birth. Thus, being attracted to women with swollen boobs as opposed to the flat chested girls who can't seem to give birth may increase the rate of successful reproduction.

Once men have evolved a desire for enlarged boobs, women may evolve larger boobs while not pregnant so as to attract those men that have developed the desire for large boobs.

And to recapitulate my stance on why modern men often do not seem to share this desire for "large boobs," I believe the reason is because ancient women had much more active lifestyles and did not eat so much, so a modern girl with the same genetic makeup as an ancient girl will have more breast fat (and overall) fat than the ancient girl, which we have developed an attraction for...because most men probably didn't evolve an attraction towards enormous boobs, but rather slightly enlarged boobs relative to other males.

You will find that even those men who typically say they prefer small boobs (such as myself) still do prefer there to be SOME boob...so they are not completely flat chested. The men who do prefer completely flat chested are more likely just pedophiles.

 

[Saladsamurai]

women with small boobs are usually unattractive.

wtf?

 

[rootX]

wtf?

OP:

From an evolutionary perspective, why do women have bosoms?

and

I think probably the easiest way to make it possible to be falsified would be to see if there's a relationship between bosom shape/size and how much money a woman's husband earns?

Simple answer:

women with small boobs are usually unattractive.

He asked for opinions and I gave one of mine.

(Note that attractive/unattractive are subjective words.)

 

[arildno]

women with small boobs are usually unattractive.

Why the inserted words "with small boobs"??

 

[rootX]

Why the inserted words "with small boobs"??

I should have used "without boobs".

 

[WhoWee]

The men who do prefer completely flat chested are more likely just pedophiles.

Or perhaps they fell in love with the person - who is so equipped?

 

[tyroman]

From;
http://en.wikipedia.org/wiki/Venus_figurines

"The female figures, as part of Upper Palaeolithic portable art, appear to have no practical use in the context of subsistence. They are mostly discovered in settlement contexts, both in open-air sites and caves; burial contexts are much more rare."

Yeah, let's bury him with his Playboy collection! LOL

 

[junglebeast]

Or perhaps they fell in love with the person - who is so equipped?

Sure, a man can fall in love with a flat chested girl...but my statement was only in regards to men who "prefer [women] completely flat chested." I suppose you could argue that some men develop a preference for flat chested women because it reminds them of a former lover who was flat chested, but that's a stretch...

 

[Jimmy Snyder]

I think its sad to for somebody to think that attraction is a byproduct of society. You can't teach someone to be attracted to specific features.

I can't speak to the sadness issue, but the specific features that attract are different in different societies. The Japanese male is attracted by the nape of a woman's neck. How can you explain that except that the attraction is learned?

 

[Proton Soup]

Sure, a man can fall in love with a flat chested girl...but my statement was only in regards to men who "prefer [women] completely flat chested." I suppose you could argue that some men develop a preference for flat chested women because it reminds them of a former lover who was flat chested, but that's a stretch...

sexuality is complicated. don't forget that some men may prefer women with more masculine features and vice versa. some are bisexual. and some have fetishes, perhaps based on some early imprinting.

 

[Moonbear]

Further, it makes a distinction between fertile women and infertile women, because a girl with lactating breasts has already had a baby, showing that she is capable of giving birth. Thus, being attracted to women with swollen boobs as opposed to the flat chested girls who can't seem to give birth may increase the rate of successful reproduction.

Unless I have completely misunderstood your post, are you suggesting that larger breasts are a sign of promiscuity? Otherwise, if you've already been successful at reproduction with SOME OTHER man, how is it a helpful indicator to a man who has not fathered her children?

I'm not actually saying you're wrong, just that's what comes to mind from your comments. Who knows...promiscuity may have been much more common and more desirable than monogamy sometime in the past to make it evolutionarily relevant...or at least serial monogamy. It's not that entirely far-fetched, as I think about it.

 

[junglebeast]

Unless I have completely misunderstood your post, are you suggesting that larger breasts are a sign of promiscuity? Otherwise, if you've already been successful at reproduction with SOME OTHER man, how is it a helpful indicator to a man who has not fathered her children?

Not so much promiscuity...

If a woman is breastfeeding, then she has successfully birthed a child (assuming she's not caretaking), thus her enlarged breasts are a sign of fertility. If other women are dying in childbirth due to being too small, having egg issues, or other things, then it may be evolutionarily advantageous for men to be attracted to women who have proven themselves to be fertile in this way. This could apply to other men, or to the same partner that gave her the first child.

Secondly, a man is more likely to stay with the female, protect and care for her and the child, if he remains attracted to her. Thus, it makes sense for a man to be attracted to the enlarged breasts of his mate for this other reason as well.

 

[billiards]

Obviously men do find breasts attractive, but I don't think it's particularly good evolutionary science to say "women evolved breasts because men found them attractive". I could accept a sort of iterative progression, a kind of feedback loop that propagated protruberances of the female chest involving stepwise increases in attractiveness related to fertility -- but according to the evidence presented in this post magnitude of breast is not the issue so why would the breast continue to grow beyond the critical "fertility level"?? Furthermore, if breast size really is an indicator of fertility (in mammals), then why haven't other animals evolved breasts by the same reasoning??

 

[TheStatutoryApe]

Sure, a man can fall in love with a flat chested girl...but my statement was only in regards to men who "prefer [women] completely flat chested." I suppose you could argue that some men develop a preference for flat chested women because it reminds them of a former lover who was flat chested, but that's a stretch...

A flat chested woman can have other feminine features. I've personally found myself rather attracted to a couple of women in my past that were flat chested but had very wide hips (I'm not a breast man to begin with). The advantage small breasted / flat chested women have is that they do not really wind up with 'withered' or otherwise unattractive breasts.

...but according to the evidence presented in this post magnitude of breast is not the issue so why would the breast continue to grow beyond the critical "fertility level"?? Furthermore, if breast size really is an indicator of fertility (in mammals), then why haven't other animals evolved breasts by the same reasoning??

It was likely not so much an indicator of fertility but of health and fitness which have a positive correlation with fertility. A female's breasts increase in size if she gains weight which means she has a steady source of food and would make a good mate. A female's breasts can shrink/flatten if she is suffering from starvation, malnutrition, or even disease which all make the female a poor choice of mate.
Sooo.. males that found large breasted females attractive and mated with them were more likely to successfully reproduce passing on both the genes for females having larger breasts and the genes for males being attracted to larger breasts. So long as the size of the breasts remain good indicators of health, fitness, and fertility the genes will propagate more successfully. So long as the size of the female's breasts do not hinder her survivability and capacity to reproduce they will increase in size to be more successful at attracting a mate. The increased size need not have anything to do with functionality.
Other animals have utters and such but most species have their own sex characteristics for attracting mates such as long tail feathers, certain markings, a certain scent, ect ect. So they may not have developed breasts but they certainly developed something. Note also that most aesthetic sex characteristics have little to no survival value in and of themselves.

 

[Moonbear]

Not so much promiscuity...

If a woman is breastfeeding, then she has successfully birthed a child (assuming she's not caretaking), thus her enlarged breasts are a sign of fertility. If other women are dying in childbirth due to being too small, having egg issues, or other things, then it may be evolutionarily advantageous for men to be attracted to women who have proven themselves to be fertile in this way. This could apply to other men, or to the same partner that gave her the first child.

Secondly, a man is more likely to stay with the female, protect and care for her and the child, if he remains attracted to her. Thus, it makes sense for a man to be attracted to the enlarged breasts of his mate for this other reason as well.

I think there's a flaw in the reasoning here. In order for a woman to have become pregnant to develop the larger, more "attractive" breasts, she had to have attracted a man to get her pregnant the first time...when she still had small breasts.

And, actually, as women become more obese (and hence have much larger breasts), infertility increases.

Given the amount of variation there is in breast size, I don't think there really has been much selection for it at all beyond that there needs to be a minimum for feeding offspring (and even then, we've had several generations now where even that has not been necessary).

 

[TheStatutoryApe]

And, actually, as women become more obese (and hence have much larger breasts), infertility increases.

How many obese people do you think there were in prehistory?

Given the amount of variation there is in breast size, I don't think there really has been much selection for it at all beyond that there needs to be a minimum for feeding offspring (and even then, we've had several generations now where even that has not been necessary).

From what I understand greater variability of a characteristic among a species is a necessity for it to be successful and selected for. If just about any member of the species could be possessed of the characteristic to the same degree as any other it is no longer a useful indicator of anything and there is no reason to select for it.

 

[Hurkyl]

And, actually, as women become more obese (and hence have much larger breasts), infertility increases.

Hrm. If we're thinking along these lines, then shouldn't we note that obesity would correlate with surplus resources? This (along with the increase in infertility) would mean there is a need to increase how often humans mate.

 

[junglebeast]

I think there's a flaw in the reasoning here. In order for a woman to have become pregnant to develop the larger, more "attractive" breasts, she had to have attracted a man to get her pregnant the first time...when she still had small breasts.

Yes...but that's beside the point. The question was why women have breasts and why men are attracted to them. Nearly all women do have breasts which are larger than necessary for feeding offspring, and nearly all men (even those men who like small breasts) still find breasts to be attractive at some non-zero size.

And, actually, as women become more obese (and hence have much larger breasts), infertility increases.

But as has been already pointed out by someone else, men don't typically like such large breasts. And as I have pointed out twice, such large breasts would not have been selected for anyway, and are most likely a result of cultural changes rather than evolutionary selection.

Given the amount of variation there is in breast size, I don't think there really has been much selection for it at all beyond that there needs to be a minimum for feeding offspring (and even then, we've had several generations now where even that has not been necessary).

Not true, almost all women have a pronounced bosom, much more than the nearly flat chested girls which are perfectly capable of breast feeding.

Also, several generations of the option for store bought bottled cows milk is entirely insignificant to the evolution of breasts.

 

[Proton Soup]

I think there's a flaw in the reasoning here. In order for a woman to have become pregnant to develop the larger, more "attractive" breasts, she had to have attracted a man to get her pregnant the first time...when she still had small breasts.

of course, a young woman has no problems getting pregnant. youth is one of the things men prefer in a mate, and is the one thing all women try to preserve.

And, actually, as women become more obese (and hence have much larger breasts), infertility increases.

i doubt obesity was an issue for most prehistoric women. all the children to rear, starting sometime shortly after menarche, plus physical labor would keep the metabolic problems of sedentary obesity at bay. whatever extra fat she did gain would likely be seasonal.