“Why are men so interested in women’s breasts?

They don’t really have anything to do with sex.”  Thus Mikel Schwartzkopf asked me and my best friend, Alan Rein, one day in the fall of 1956, our senior year at Tamalpais High in Mill Valley. Alan and I were both in love with her, but she was getting over a previous crush of her own and refused to choose between us. Unrequited love is SO painful when one is sixteen.

He and I scratched our heads, discussed the issue, and realized we did not have a clue. Not long after, as we were returning from a field trip, Alan said, “Come on” to me and had the school-bus driver let us off at Third and Market in San Francisco. He led me around the corner from where I would begin working for Scientific American Books a dozen years later and introduced me to the Mechanics Library, which had been founded by gold miners about a hundred years earlier.

He and I spent the afternoon combing through the card catalog, the reference books, the shelves, but could find nothing at all. The human female breasts did not seem to be anybody’s current research interest. Finally we walked down to Seventh and Mission, and took the Greyhound home to Marin County.

The next morning, Mr. John George, the Dean of Boys, called us into his office and said, “You two are about the brightest guys in this school. Why did you pull a stunt like that?” So we explained Mikel’s question and that we had gone to the library to do research on it. I’m sure that was an answer he could not have foreseen. He glared at us for about a minute, then said, “Get out of here.” Being a white, middle-class geek was definitely a privileged position in the 1950s.

Mikel’s question sat in the list of unanswered puzzles somewhere in my brain for many years. I don’t remember just when it was that I stumbled upon the fact that began to unravel the puzzle, the fact that the permanent human female breast is not a biological necessity, is in fact an anomaly. In every other primate species, the females develop breasts while nursing, then become flatchested again afterward. So here an anthropological concept applies: a human trait that is not dictated by biology has been created or shaped by cultural forces. In other words, the permanent female breast is the result of learned behavior and serves a social purpose. What could that be?

Puzzling over that, I was finally jolted by what by hindsight should have been obvious: when a human male observes a human female from a distance, the first fact he can observe about her is whether she has developed breasts. If she has, then she is old enough to have sexual intercourse. The permanent breast is a signal, a communication of information essential for human survival. Evolutionary pressure created it.

Until about 15,000 years ago, the only unit of human society was the hunting and gathering band, an extended family of roughly two or three dozen people. That social structure and the individuals in it had been evolving for at least 200, perhaps even 800, millennia, and we have not had time to change much in only the last 15. We are all saddled with bodies that evolved to survive in very different conditions. (I think our minds, however, have a very different story.)

A basic hypothesis of sociobiology is that traits which increased a band’s chances of survival would have had a reproductive advantage and therefore would have gradually become more prevalent. One can guess at what some of those traits may have been, partly by considering the probable makeup of such a band. First, of about 30 people, half would be male, half female. Further, roughly half would have been adults, the rest children; so a band would have had about 7 or 8 women of childbearing age. If we assume that the average life expectancy was about 35 years, that the infant mortality rate was about 80 percent, as it was until the 1930s, and that women were less likely to become pregnant while nursing an infant  (whether because of biological factors or because of group rules), then a ballpark estimate is that each woman would have had about ten children, of whom two survived to adulthood. That is, the reproduction rate hovered at the edge of being able to maintain the size of the group. Given what the effects of accidents or communicable diseases might have been, human survival was anything but guaranteed, and any factor that decreased the chances of survival must have been strongly selected against.

So, the breast. If a male had intercourse with an immature female, often enough she would have been harmed, thus reducing her chances for survival and childbearing. Such behavior could have wiped out a band within a few generations that lacked enough generation. Hence being able to gauge a woman’s physical maturity became crucial. The permanent breast developed as a signal in order to make that gauging possible. In other words, the human male co-evolved to perceive the permanent female breast as a signal of female availability and to be sexually aroused by it. Further, the larger the breast, the more mature the female was. Conversely, the male would not have been aroused by a flatchested, immature female. This linkage was, I suggest, patterned into our DNA for several hundred millennia. I can further suggest that pedophiles have lost an essential element of out survival software, just as sociopaths have.

I suspect that any feminists reading this line of thought may be now be horrified at what the condition of women in such a band might have been. But I think women were probably more valued, cherished, and honored in such bands than women have been ever since agriculture was invented. Survival depended entirely on the women, not on the men. It’s logical that any man who purposely harmed a woman would have been killed or at least banished. Rape, the obvious concern, would have been a capital offense and therefore very rare. The cartoon image of a fur-clad male bashing a woman on the head and dragging her off is as ludicrous as thinking that the Flintstones had a pet dinosaur.

Paleologists have long ago proposed that there could have been only three specialized occupations in such a band, those of the chief, the “shaman,” and the toolmaker, with the latter two just as likely to have been held by women as by men. They could be at least partially supported. All the others, including children by about age four, needed to collect food, the men by hunting, the women by gathering plant food and catching “slow game” (women, unlike men, some suppose, had the patience to sit motionless long enough for the stupid rabbit to stick its head out of its burrow).

The chief would have been the “alpha male,” the strongest, fastest, and smartest of the men, but not a cruel dictator; cruelty would have decreased chances for survival. He led the hunt and had the social skills needed to maintain adequate group harmony. He probably also fathered more children than any other man in the band. Why? Because the mature women would simply have offered themselves to him whenever he wanted to have sex, because his children were the ones most likely to survive. (No point to arguing about whether this was “conscious” or “instinct”; it just had survival power.)  He probably did not think he “owned” them, but they were all under his protection, and it was he who would punish any man who harmed or attempted to rape a woman.

Women’s reactions to alpha males can be observed even now, although alphaness is a trait not of the man, but of the way women perceive him. Consider the lives of celebrities. Not all but many women perceive actors, rock stars, athletes, the rich, famous, and powerful, as alpha males, and react to them very differently than they do to beta males. Women in Neil Diamond’s audiences flashed their breasts at him, and women wear plunging necklines at prestigious events. My wife, who worked in Hollywood for a decade, tells me tales of respectable middle-class women who did not hesitate to go to bed with a celebrity—then wonder in bewilderment afterward about what had come over them. That what, I suspect, was an atavistic instinct that once helped guarantee our survival. As dumpy old Henry Kissinger once said, “Power is the ultimate aphrodisiac.” I just read a wonderful blog on FB about the emotional dilemma many women have of wanting to both display their breasts and yet not have them looked at. I think perhaps women may unconsciously want to attract the attention of alpha males, of whom there are not enough around.

No beliefs about sexual morality that evolved after the invention of agriculture are relevant for understanding those bands of twenty and more millennia ago.  Given the existence of dominant and recessive genes, no human could guess how viable the progeny of any one person might be. Hence for a man to impregnate as many different females as possible, and for women to be impregnated by as many different men as possible, would have increased the chances for having viable children. It is thus far more likely that all the physically mature adults functioned as a group marriage, and that all the children were a collective responsibility, than that there was exclusive pair-bonding in such a band.

What about the problem of inbreeding (not as big as many think) or incest taboos (if they had any)? Our closest genetic relatives, the bonobos, share an otherwise exclusively human trait: the females have a menstrual cycle, not an estral one, and are thus able to have sex all time. If two bonobo troops meet at the border between their territories, they party. Similarly, if two human bands met at the edges of their traditional turfs, they would have partied also. The women would especially have wanted to have sex with the other band’s chief. Also, if younger women liked the looks of the men in the other band, they were probably free to join it—although there would probably have been social pressure to have an even exchange. This increase in the diversity of the band’s gene pool also had survival value.

I apologize to the authors of Sex at Dawn (which I haven’t gotten hold of yet) if I have reinvented their argument. My real point in all this is that, even if my speculations are not totally accurate (and I don’t suppose they are), the instincts, genetic software, and other possibly inherited traits forged during those ten or hundreds of millennia are still within us. We have not evolved further, and they conflict with many of the ethical and moral rules humans have tried to devise, especially during the last three millennia. I propose we need to look more consciously at our sociobiological nature. Then maybe a more rational game plan could be devised to improve the quality of life for more of the human race.

Yeah, I like to think big. I’ll be going over some of this in the last session of my ethics course tonight, using the chapter on sexuality, about the only one I agree with, in the humanist text I’m saddled with, which chapter the honchos at HQ were too chicken to include in the syllabus. Would have let out much of the fun—as well as the most difficult ethical questions that most people have to deal with in real life.