We give out Nobel Prizes in scientific fields like physics and chemistry, but the human brain also deserves a gold medallion for its extraordinary ability to create and maintain social networks, such as corporations, government agencies, and basketball teams, in which people work smoothly together to accomplish a common goal with a minimum of miscommunication and conflict. Perhaps 150 is the natural group size for humans in the wild, unaided by formal organizational structures or communications technology, but given those innovations of civilization, we have blasted through the natural barrier of 150 to accomplish feats that only thousands of humans working together could possibly attain. Sure, the physics behind the Large Hadron Collider, a particle accelerator in Switzerland, is a monument to the human mind. But so are the scale and complexity of the organization that built it—one LHC experiment alone required more than 2,500 scientists, engineers, and technicians in 37 countries to work together, solving problems cooperatively in an ever-changing and complex environment. The ability to form organizations that can create such achievements is as impressive as the achievements themselves.
THOUGH HUMAN SOCIAL behavior is clearly more complex than social behavior in other species, there are also striking commonalities in certain fundamental aspects of the way all mammals connect with others of their species. One of the interesting aspects of most nonhuman mammals is that they are “small-brained.” By that, scientists mean the part of the brain that in humans is responsible for conscious thought is, in nonhuman mammals, relatively small compared to the part of the brain involved in unconscious processes.19 Of course, no one is quite sure exactly how conscious thought arises, but it seems to be centered mainly in the frontal lobe of the neocortex, in particular in a region called the prefrontal cortex. In other animals, these regions of the brain are either much smaller or nonexistent. In other words, animals react more and think less, if at all. So a human’s unconscious mind might raise an alarm at the sight of Uncle Matt stabbing his arm with a shish kebab skewer, only to have the conscious mind remind that human that Uncle Matt thinks it is funny to perform shocking magic tricks. Your pet rabbit’s reaction, in contrast, would probably not be mitigated by such conscious, rational considerations. The rabbit’s reaction would be automatic. It would follow its gut instincts and simply flee Uncle Matt and his skewer. But although a rabbit just can’t take a joke, the brain regions responsible for a rabbit’s unconscious processing are not that different from ours.
In fact, the organization and chemistry of the unconscious brain is shared across mammal species, and many automatic neural mechanisms in apes and monkeys and even lower mammals are similar to our own, and produce startlingly humanlike behavior.20 So although other animals can’t teach us much about ToM, they they can provide insights into some of the other automatic and unconscious aspects of our social tendencies. That’s why, while other people read books like Men Are from Mars, Women Are from Venus to learn about male and female social roles, I turn to sources like “Mother-Infant Bonding and the Evolution of Mammalian Social Relationships”—which, some say, serves to minimize the mammalian social relationships in my own life.
Consider this quote from that work:
Reproductive success in males is generally determined by competing with other males to mate with as many females as possible. Hence, males rarely form strong social bonds and male coalitions are typically hierarchical with an emphasis on aggressive rather than affiliative behavior.21
That sounds like something you’d observe hanging out at a sports bar, but scientists are discussing the behavior of nonhuman mammals. Perhaps the difference between human males and bulls, tomcats, and male sheep is not that nonhuman mammals don’t have sports bars but that, to nonhuman mammals, the whole world is a sports bar. Of females, those same researchers write:
The female reproductive strategy is one of investing in the production of a relatively few offspring … and success is determined by the quality of care and the ability to enable infant survival beyond the weaning age. Females therefore form strong social bonds with their infants and female-female relationships are also strongly affiliative.
That, too, sounds familiar. One has to be careful about reading too much into mammalian behavior “in general,” but this does seem to explain why it is mostly women who have slumber parties and form book clubs, and why, despite my promises to be affiliative rather than aggressive, they have never let me into either. The fact that on some level human and nonhuman mammals seem to behave similarly does not mean that a cow would enjoy a candlelight dinner, that a mother sheep wants nothing more than to see her babies grow up happy and well-adjusted, or that rodents aspire to retiring in Tuscany with their soul mates. What it does suggest is that although human social behavior is far more complex than that of other animals, the evolutionary roots of our behaviors can be found in those animals, and we can learn something about ourselves by studying them.
Just how programmed is the social behavior of nonhuman mammals? Take sheep, for example.22 A female sheep—a ewe—is by disposition rather nasty to baby sheep (or, as the meat industry likes us to call them, lambs). If a lamb approaches, wishing to suckle, the ewe will scream at it with a high-pitched bleat, and maybe throw in a head butt or two. However, the birthing process transforms the mother. It seems magical, that transformation from shrew to nurturer. But it doesn’t seem to be due to conscious, maternal thoughts of her child’s love. It’s chemical, not magical. The process is instigated by the stretching of the birth canal, which causes a simple protein called oxytocin to be released in the ewe’s brain. This opens a window of a couple hours’ duration in which the ewe is open to bonding. If a lamb approaches her while that window is open, the ewe will bond with it, whether it is her baby, her neighbor’s, or a baby from the farm down the street. Then, once the oxytocin window has closed, she’ll stop bonding with new lambs. After that, if she has bonded with a lamb, she’ll continue to suckle it and to speak soothingly to it—which in sheep talk means low-pitched bleats. But she’ll be her nasty old self to all other lambs, even to her own if it didn’t approach her during the bonding window. Scientists, however, can open and close this bonding window at will, by injecting the ewe with oxytocin or inhibiting her from producing it herself. It’s like flicking a switch on a robot.
Another famous series of studies in which scientists have been able to program mammalian behavior by chemical manipulation concerns the vole, a small rodent that resembles a mouse and encompasses about 150 different species. One of those species, the prairie vole, would be a model citizen in human society. Prairie voles mate for life. They are loyal—among prairie voles whose partner disappears, for example, fewer than 30 percent will shack up with someone else.23 And they make responsible fathers—the males stick around to guard the nest and share in the parenting. Scientists study prairie voles because they are a fascinating contrast with two related species of voles, the montane vole and the meadow vole. In contrast to prairie voles, montane and meadow voles form societies of sexually promiscuous loners.24 The males of those species are, in human terms, ne’er-do-wells. They will mate with whatever female is around, then wander off and leave her to take care of the kids. If placed randomly in a large room, they avoid others of their species, preferring to crawl off to some isolated corner. (Prairie voles, on the other hand, will cluster in little chat groups.)