It's not necessarily true that men all have this preference.

See George Orwell's Burmese Days where he talks about how people there feel the opposite way about breasts.

Perhaps it is something that has been created by society rather than an evolutionary process

In primitive tribes such as mentioned by Orwell, large breasts indicate the woman is lactating and not yet able to conceive after childbirth, but small breasts indicate that she is likely to be menstruating again. Age can be told by other features. The waist thickens after the menopause.
I believe the thing for big breasts is cultural and that men are indocrinated to think this way. When legs were covered in Victorian society, the sight of an ankle or calf was eroticised. In Muslim society a whole lot more is eroticised by it's not being visible, such as arms! In ancient China there was erotic obsession with deformed feet - the result of cruel bandaging in childhood.

I find the obsession with big breasts unhealthy because it is commericialised and women are maiming themselves with implants, such as the model pictured, while heavy breasts cause physical pain as well.

I will refrain form both agreeing and disagreeing with Marlowe's theory as I know nothing more of it than what this blog post has mentioned.

However, I believe there is more truth to the second explanation for why large breasts are considered more attractive; that they are a sign of high levels of female reproductive hormones.

Though both the explanations--youth and fertility--are reasonable, I belive the latter is more so.

Like tight waists are associated with high levels of osetrogen and progesterone, so are also wide hips. I recall having read somewhere that the women who are considered the most attractive are those whose circumference of the waist and breasts are equal, or almost so. This is in line with the theory of high levels of hormones; that such levels give a woman wide hips, a narrow waist and large breasts.

Further support for this - however informal - is that I myself have seen very few women with small breasts who also happened to have wide hips and narrow waists. I believe such an appearace is rare, does it exist at all.

I believe more in the latter than the former theory, for even if it is true that large breasts sag more then small breats, it is still true that even small breasts sag with age. I am no expert in the field, but I think it is just as easy to say whether or not a breast has sagged, no matter its size. All hair turns grey, which is easy to tell whether it is short or not (if you excuse me such an impromtu metaphor).

Why exactly is this important?

I generally find evolutionary explanations persuasive, but cases like this one always bring up a question for me. If a trait like breast size is driven by (for the benefit of) sexual attraction, why is there so much variation? It seems like there would be an arms race of sorts resulting in features that differ only subtly (perhaps by chance). To put it bluntly, there are plenty of women with smaller breasts who presumably descended from ancestors with smaller breasts who nonetheless succeeded in reproducing.

A contrast that occurs to me is the peacock's tail. My understanding is that this is also due to the pressures of attracting mates, but as a result most peacock's tails are roughly similar (unless of course the animal is ill or injured). Do peacocks' tails differ as much in the eyes of pea hens as breast size does in the eyes of male humans, or is the case not analogous? If the latter, how so?

Could it simply be that breasts are inherently feminine and thus attractive to straight males? A woman with large breasts differs more from the male form, just as women generally prefer taller men with a stature that differs from thier own. Pear shaped men aren't often deemed as sexy. Even small breasts can be displayed in cleavage revealing shirts or accented in some way. My boyfriend claims to be a butt man and that breasts "don't really do much for him." Still, when I wear a more revealing top ( am of average breast size) he is always very complimentory.

Wait a second.

The first post in this series stated that it would be explained how "youth, long hair, small waist, large breasts, blonde hair, blue eyes, and large eyes" are evidence of beauty so convey competitive advantage in mating.

But Duh? What about the combinatorial explosion of varying attributes across the spectrum of characteristics? E.g., a woman with a large waist and large breasts versus the opposite. Which one is more attractive? Bad hair, but it's blond? Small breasts but she's young? And all of the gradations in between?

And I happen to be a leg man. How do gams play into this model? (And believe me, they play...)

It's absolutely ridiculous to discretely focus on one characteristic in each column while ignoring the others. Because believe it or not, women are complex creatures that present themselves as a package. Which of course yields the genetic amalgamations of that we see in real life.

More speculative barstool talk masquerading as science. I'm getting woozy from all the hot air. Kanazawa's turn to buy while I step outside...

I'm not even sure where to start on this one.

Theory 1:
Breasts are fatty tissue, a woman cannot have big breasts unless she has an abundance of nutrients (or is lactating). It's possible there is a genetic limit on what a woman's breast size should be (like everyone has a genetic set point for their natural healthy weight/fat distribution), but it is very possible to go past that set point based on diet. So breast size would be a sign of a wealthy/resourceful woman in ancestral times who has enough means to support big breasts? ('Course not... only men had their genetic fitness based on wealth of means).

Theory 2:
Heavy breasts sag. It's called gravity, but bigger breasts sag even when they're young and nubile. Trust me, my breasts are not perky and I'm 21, but that kind of goes with territory of have D cups. Same goes for my same-aged friends who have DD or G cups. By the logic here, if saggy breasts mean you are no longer in you're most fertile year then only women with breasts who don't sag are good mates. If the only women who have appreciably non-saggy breast are A cups, B cups, and a few perky C cups then only women with smaller breasts would be preferable. (Also, not wearing bras and certain posture/sleeping habits can, over the years, aid the saggifying of breasts... so wouldn't the ancestral humans ((i.e. those without bras)) have saggy boobs in general?)

Theory 3:
Breasts are the easiest secondary sex characteristic to recognize. In a society such as ours, which is highly dependent on a gender diochotomy to organize around, being able to easily and reliably recognize a male or a female is essential. It's no small leap from there to see how bigger breasts could become idealized and even fetishized.

Theory 4:
The preferred breasts size is cultural. Looking at historical art pieces (both realistic and fantasy) we can see that the ideal breast size has definitely changed over the millennium. In ancient times, as evidence by Egyptian and Greek artistry, the ideal breast size was very small. Aphrodite, the most beautiful woman in the world, has small breasts. Most of the large busted figures from early civilizations are some form of Venus figurine or fertility statue. So what could be the cause of big breasts being ideal in today's society? Could it be socialization?

I could come up with so many more. There are so many ways to alternately explain what Dr. Kanazawa's brand of EP preaches, especially in ways that directly oppose their hypothesis.... oh wait, they're not hypothesis because they are not reliably falsifiable with replication.

I've read all your stuff and you have so many haters. Methinks they blog protest too much. You're saying things that may be general, theoretical and vague at times, but why all the venom from the commenters? Could it be you're hitting a vein?

My theory: people hate what you say because there is truth inside and they don't or can't measure up to that truth. They've spent their whole lives trying to convince themself they're ok without a good figure or blue eyes, etc., and then you come along and tell them Barbie had it right all along. The mountains of rationalizations and exceptions you read in your comments echo what these people have told themself all their lives to convince themself they're okay not being Barbie.

It's ironic that a society that is so gung ho on evolution has such difficulty accepting that some of their traits may not be the top choice. Look readers - evolution is a brutal process of selecting for the strongest traits. You might not have all those traits. Can you come to accept this?

This seems to miss the obvious question: why don't men find breasts unattractive, as I'm pretty sure *all* other male mammals do? They are, after all, a sign of lactation, which means lowered fertility... at least, for all other mammals this is so, and must have been so for proto-humans as well.

Ignoring this puzzling fact seems to make the rest of the argument considerably less convincing.

I'm attracted to small-breasted women. I also like brunettes - I guess I must be an evolutionary failure.

This article embodies why the so-called 'science' of evolutionary psychology pisses me off: it takes a modern, Western concept and gives it a universal evolutionary perspective - without a SINGLE regard for other cultures and time periods that don't hold the same standard.

Ever seen a Classical Greek statue before, Satoshi? Or a Renaissance or Baroque nude painting? Or a photo of Louise Brooks? Evidentally not - because then you'd realize that, in many times, a smaller bust has been the ideal even in Western culture.

Whoops! Your theory doesn't make sense anymore.