Imus and dating

I was on Imus yesterday. You can listen to the interview here.

Today is Valentine's Day. For some people, it is one of their least favorite days of the year. Although anyone stuck in dating hell probably finds it difficult to think about their situation as a boon to humanity, I want to take a few moments to praise dating as one of the key activities that shaped who we are as human beings. That’s right—lowly dating turns out to be essential to our humanity.
To understand why, we need to look at how the size of our social groups plays such an important role in shaping who we are. One of the leading theories for why human beings developed large brains is called the social brain hypothesis. The idea is that the size of our social groups has played the essential role in pushing humans to develop larger brains. Many primates, such as chimpanzees, live in reasonably large troops, usually between twenty to fifty members. But no animal is more social and lives in larger groups than man. There are many advantages to larger groups, but there is one serious disadvantage: negotiating relationships with all the members of the group. Rewarding friends, seeking allies, and avoiding enemies all require more brain power as the group gets larger. Researchers have found that the larger an animals’ group size, the larger the percentage of the brain devoted to the neocortex (the outer layer of the brain, which accounts for most cognitive abilities). For most mammals, the neocortex makes up 30 to 40% of the brain. For highly social primates, such as chimpanzees, the percentage rises to 50 to 65%. For humans, the neocortex takes up a staggering 80% of the brain (and our brains are seven times larger than you would expect for a mammal of our size).
According to social brain theorists, the size of human groups also played a key role in the evolution of language. For other primates, the glue that keeps the group in relative harmony is grooming, that staple activity of animal behavior shows when, for example, one chimpanzee combs through the hair of another to untangle fur or remove nits not just for reasons of hygiene but also to re-affirm the social bond between the two. But grooming is time consuming, too time consuming for humans once their group size began to grow beyond fifty. Imagine trying to use grooming to hold together a large corporation. Nothing would ever get done. So language came to serve as a kind of accelerated social grooming, allowing group members to maintain relationships on a much larger scale. For social brain theorists, language developed not primarily for informational tasks, such as where to find a wildebeest, but so that we could gossip about one another. Gossip served not as a distraction from the task at hand but as the main business, establishing and defining our relationships with other members of the group.
If we take Darwin’s idea of sexual selection seriously, we can narrow the driving force behind brain growth even further. We may, in fact, be able to pin it entirely on the need to find a mate. In other words, the central purpose behind our enormous brains may be to help us negotiate the unruly world of dating. Evolutionary psychologist Geoffrey Miller, a leading proponent of this theory, has even gone so far as to call the human mind a “protean courtship device.”
The reason mating is a plausible force behind our brain growth is because of something known as runaway sexual selection, which occurs when both the trait and the preference for the trait are heritable. In this case, if the main social difficulty that we face as a species is securing a mate, and if the most essential trait to accomplish that is our intelligence, and if intelligence is heritable, then sexual selection will lead to greater intelligence. And if the preference for intelligence is also heritable, then sexual selection will boost human intelligence even more dramatically (this is where it becomes runaway). And what really supercharges runaway sexual selection in our species is that women are not the only ones looking for intelligence. Men also tend to want intelligence in their mates, although not as avidly as women. With both sides choosing for intelligence, you can see why “runaway” is an apt description. I guess you could call this the Don Juan theory of human development.
Once you look at things through the lens of sexual selection, there is almost no aspect of human culture that remains untouched by it. So, dating is a plausible force behind everything in human development from Bach to skyscrapers, something to keep in mind the next time you find yourself railing against the indignities that often occur on actual dates.

Some pre-Valentine's Day thoughts

As I sit here a couple of days before Valentine’s Day, I find myself reflecting back on why I wanted to write Decoding Love in the first place. Although I hope, of course, that the book reaches a broad audience, my goal was never to become a love guru. Both my temperament and my research have taught me to be skeptical of gurus. For good or for ill, any final answers about love must come from ourselves.
I also did not set out to write a book of dating advice tips. Don’t get me wrong. I am not trying to disparage the idea of practical dating advice. I think there are some helpful pointers in the book, and I will be thrilled if readers find any of them useful in their quest for love. In fact, some of my favorite parts of the book are in the tips section. Who knew, for example, that a spicy-floral fragrance could make a woman appear twelve pounds lighter? If they could just discover the scent that would make me look like George Clooney or Brad Pitt, I would be a happy man.
But ultimately I was drawn to this subject by something deeper and more fundamental—the sense that our romantic lives could tell us something profound about our humanity.
I know that sounds somewhat grandiose for a book that spends a lot of time discussing dating, so let me try to explain what I mean. In part, my goal stemmed from a basic belief that sexual selection has played perhaps the key role in shaping who we are. In fact, if you really take sexual selection seriously, it is difficult to find any aspect of being human that is not touched by it. For instance, one of the things that distinguishes us is our sense of humor. There is a playfulness about our species that is one of the great joys of life. It turns out, though, that humor is not just there for the giggles. Study after study has shown that it plays a key role in mate selection. Simply put, if you are a humorless oaf, it’s going to be difficult to find anyone who wants to be with you. And you can extend this to all of our other traits as well—our tendency to cooperate or to help people in need. So, part of what I was interested in exploring was how something like attraction could provide a window into something much larger—who we, as human beings, are.
Because I believe attraction does play such a central role in the human drama, I was also able to make the opposite move. In addition to showing how mating shapes who we are, I could range far afield and show how seemingly distant fields offered insight into how attraction works. Although applying fields like consumer psychology to attraction is not at first a self-evident connection, it starts to seem perfectly logical once you have accepted how deeply the need to find a mate has shaped us. And that allowed me to branch out from a narrow conception of my topic to one that could encompass a much broader array of concerns ranging from how the minds works to the hormonal shifts behind female fickleness.
Despite all of those grand ambitions, though, my ultimate goal was fairly simple. I didn’t write Decoding Love thinking that it would provide any easy answers about finding love—far from it, in fact. But I did hope that it would offer a persuasive explanation of who we are and why, when it comes to things like attraction, we act the way we do. In the end, this book was written with the optimistic hope that simply understanding the nature of attraction would help people better withstand the inevitable vicissitudes of romantic life, whether they were looking for love, in love, or losing love.
If it manages to do that, I will be very happy indeed.

Sperm and superiority

The latest study offers an interesting twist on what women should look for in a man--good sperm. Okay, okay, I know the next question: how does one go about finding good sperm? Well, it turns out that all a woman needs to find is an intelligent man. A recent study discovered a clear link between intelligence (as measured by something called Spearman's g) and sperm quality. Since we are all shaped by sexual selection, this is not a shocking finding, but it does offer an interesting window into just how deeply that sexual selection has shaped our species. On first blush, most of us would probably assume that there were many good reasons for the development of intelligence that had nothing to do with attracting a mate. But this study suggests the possibility that we have put the cart before the horse. Perhaps sexual selection is actually the driving force behind the expansion in human intelligence, and the many other uses we find for our brains are actually just fortunate byproducts of that sexual selection. Who knew that dating might hold the key to human evolution?