Humans are the only species where the female continues to have engorged breasts even when they are not pregnant. A popular line of thought is that evolution has produced this effect as an aesthetic mating rite. The thought is that men like women's breast because the pair of breast come together and look like a woman's butt. Alternatively, there is a line of thought that a woman who has large breast gives the impression of being able to bear lots of children and produce lots of milk.
However, observation depicts a totally different scenario.
I woman who is in good physical condition generally has an upper body that is not totally dissimilar to a man who is in good physical condition. This is very indicative of sociological processes and traditions taking place.
In early tribal communities, women performed as much work as men. Men of tribal communities do not look at women's breasts in a sexual context. It is only in postagricultural communities that a woman's breasts take on any form of sexual significance.
In early agrarian society, a woman was little more than livestock. They were bought and sold for purposes of implanting "seeds" and producing offspring. Thus, a woman had little opportunity for activity that would result in exercise, leaving them to become extremely sedentary. Thus women tended to gain weight, and much of that fat went into their chest area, producing the enlarged breast that we see in women today.
So it can be shown that the man who drools over a women with large breast is not doing so because the breast produce a desirable evolutionary effect or sexually ideal effect. It is because a woman with large breast is thought to be sedentary and docile, a woman who knows her place. It is a sociological need in many men for dominance, and a way of women to show submissiveness.
So women who undergo breast augmentation are actively making an effort to show that they are willing to be ruled over by men. What does that say about our society today, I wonder?
I am become death, destroyer of worlds