I agree with you here. I don’t think breasts and buttock are similar in any way. Maybe when breasts are purposely squeezed together to expose cleavage the crack looks like a butt crack, but other than that, no, sir. Nothing. I don’t see it.
But how rare is that? Very. How many women have breasts large enough to even resemble a butt? This point is really reaching out there into the abyss and quite honestly, silly.
No it isn’t: remember, I’m talking about a sideways view. Seriously, dude, I checked this in the mirror, and while my personal gazongas are certainly not large enough to mimic a pair of buttocks in a head-on view, from an oblique angle they definitely do give an impression of a deep buttocks-like cleft between the parallel swelling curves. Especially when leaning forward a bit. (No cites, sorry, but come on, you can see the same effect in any of several million pictures on the internet.)
Of course the mimicry isn’t anywhere near perfect; I don’t have nipples on my buttocks, for one thing, and the shape of the upper breast curve is significantly different from that of the buttock curve. But if the basic visual signal you respond to is “symmetrical pair of roundish swellings with a cleft between them”, the typical set of breasts, viewed obliquely, can definitely send that signal.
(If anybody had told me I’d ever be talking about my boobs on the Dope, much less in a GQ thread, I wouldn’t have believed them. But it’s about fighting the ignorance, dammit.)
Again, this is a so what. Yes, you have roundness. You have it in several places on your body. Yes, presumably men find roundness appealing in women.
But so what? There are some species in which sexual displays and differences between the sexes are obvious and manifest, and of importance to the mating ritual. There is no evidence that humans have any such sexual differences. All we can say is that there are obviously sufficient differences between the sexes so that they can tell one another apart (naked, close up, most of the time) and the sexes obviously are attracted to one another, but both of those are givens for just about every sexed species. And both men and women are equally part of the sexual process, either can pursue the other.
Nothing has been said that amounts to more than that. Yes, women are generally rounder than men. And men are generally more heavily muscled than women. Both are ranges rather than absolutes. (In some species all males are larger than all females.)
Why haven’t people been asking the obvious question, which is why, if female breasts and buttocks are such a sexual signal, aren’t men selected for penis size? Yes, humans have a penis proportionally large to the body compared to other apes, but it’s an obvious display signal. Why aren’t men even larger compared to women if musculature is such a sexual selection trigger? Why are humans so closely comparible to one another? We keep talking about female attributes, but females pick males as much as males pick females. Why no talk of them?
The answer, it seems to me, is clearly cultural rather than genetic. We culturally idealize and fetishize women more than we do men. Why that might be raises some interesting discussion points. But the reasons that we look the way we do appear to be buried in the far distant past, probably pre-homo. Nothing we have done in the entire existence of our species appears to have changed that an iota.
The real discussion is probably what Australopithecus or even Paranthropus preferred and why. But we’ll probably never know that.
I’m not arguing that point. I was just noting that even breasts without bra-induced cleavage can visually resemble the “cleft” effect of the buttocks, which diggleblop and RealityChuck seemed to disbelieve.
Whether the breasts of early female humans looked enough like the buttocks to provide an equivalent sexual stimulus, or whether the early human female buttocks themselves provided an evolutionarily significant sexual stimulus at all, is something I have no opinion on.
A friend of mine, when leaving his home in remote outback Queensland to come to university, was taken aside by his father and told:
“Now mate, when you’re down there in Brissie [Brisbane] you have your fun, orright? We both know what I’m talkin’ about. But listen: don’t you go bringin’ no narrow hipped women back here. You understand me, son?”
Before you can ask that question, you need to have a good idea what the penis would be like if it evolved purely along functional lines and wasn’t a sexual signal in any way. Dawkins had some interesting speculation about this in one of his books.
What’s so interesting about human female breasts (haha) is that, from a functional standpoint, they clearly don’t need to be anywhere near as big as they are. Given the widescale human male attraction to human female breasts (across many different times and cultures), it’s reasonable to hypothesize that large human female breasts are a sexual signal that evolved along with human male attraction to the same.
Burmese, I think.
How do you know that women don’t select men for penis size? In fact, your statement that human penes are proportionally larger than for other simians strongly implies that they do, and that our present proportionas are the result.
Men, as a group, are generally more muscular than women. This obviously comes at the expense of something else, or we’d all be massively muscle-bound (since it’s better to have bigger muscles and be more powerful than not to, and for reasons other than sexual attraction). Sexual selection isn’t the only thing affecting features. And no matter w=hat is selecting features, it has to deal with the rest of the physical universe, too. Obviously, something keeps us from all being Arnold Schwartzenegger in his prime.
The idea that the sexual attractiveness of such universally-admired features as breasts and buttocks is culturally determined strikes me as absurd.
I can imagine a race of intelligent Frigate Birds saying "Of Course we have bright red inflatable chests! But it’s not a sexual signal! We have to be able to breathe, so our chests inflate. They’re red, it’s true, but they had to be *some[/i color! Everything is strictly functional, and we only are attracted to them because we make ourselves believe that to be the case!
And in the meantime the sparrows are laughing their asses off.
I don’t know why you are saying this like it is a given, I think it is anything but.
You mean to tell me that big muscular hunter-gatherers with their higher calorie requirements are better off during, say, severe drought conditions than their more slender brethren in the next cave down?
This is the greatest thread in the history of the SDMB.
Well, this may be a bit on the nose, but hetero or homo reason is the same, you can stick your dick in it. You surely knew this to begin with, no? Why try to complicate things?
I…I…I’m torn…Would this be a good idea, or not?..the shock factor alone…might make sitting problematic…need further research.
Waistband and quicksand
But female butts are also attractive to other females.
I don’t think we’ll ever figure it out. lol
For the same reason of course, they can put things in them. 
Come to that you can stick your dick in a knothole in a tree…if that’s your thing o’ course 
I don’t think it’s an either/or situation. There can be some objective benefit to finding some traits attractive – as in, those traits signal health/well-being/greater likelihood of bearing offspring – with an added on-top ‘overshoot’ where the trait gets exaggerated simply because it’s ‘attractive’ to the other sex and then the other sex gets more attracted to it and round we go.
Considering the ‘roundness’ part in particular – the greater roundness/smoothness of women comes mostly from extra fat. If she isn’t getting enough food to maintain that fat, due to famine or illness or whatever, she’s much less likely to be able to bear children successfully. In fact, if a woman’s body fat percentage drops below a certain point, she stops ovulating. So an attraction to ‘round’ vs. ‘bony’ or ‘sinewy’ makes sense.
So a woman needs to be at least ‘somewhat’ rounded. OTOH, really large breasts or butts aren’t strictly necessary, but if having a little more padding in significant areas meant the ‘rounder’ woman was able to attract a ‘better’ mate who could provide for and protect his offspring better while her less rounded sisters made to with the doofus who couldn’t throw a spear as well (or whatever)… well, it doesn’t require a huge benefit to have an evolutionary effect.
Hmmm, you saying you don’t, mate?