Sex, Murder, and the Meaning of Life (23 page)

But although I would surely feel great resentment toward a colleague or friend who had run up a half million dollars on my account, I do not feel anger or resentment toward my sons. Instead, I feel guilty that I cannot do more. In fact, I feel bad about even writing this, because I do not want my sons to read it later and worry that I think of them in terms of “economic investments.” My two sons instead elicit my warmest and most loving feelings. Irrational economic investments though they might be, I cannot get enough of them.

Besides my “irrational” contributions to my children, I have also given thousands of dollars to the Sierra Club, the Nature Conservancy, the Brady Center to Prevent Gun Violence, and on and on. Just this week, I sent a check to an organization fighting to convince the U.S. Congress to pass a bill ensuring universal health care for other Americans. (I already have adequate health care, and like many of those old bastards who have so successfully opposed “socialized medicine” for young people, I will be eligible for Medicare in a few years.) And I have been trying to teach my younger son to be more generous toward others. Just yesterday, I gave him a dollar to stuff into the Salvation Army kettle as we walked into a store, where we were going to buy an anonymous Christmas gift for a poor family in his school.

Does all this generosity make me a candidate for canonization? Does it mean that my fistfighting sex-obsessed younger self has magically transformed into a saint? Not quite. Indeed, my apparently selfless behaviors are, from an evolutionary perspective, at least as self-serving as my seemingly selfish ones. And yours are too. How this all works begins to make sense in light of some exciting recent developments linking evolutionary psychology to classical economics.

On the classic model of rational man, we humans are reasonably well-informed decision-makers who make choices designed to maximize
our “utility,” or expected satisfaction. The general model does a great job of explaining things like supply and demand and of helping us understand how the conflicting selfish tendencies of buyers and sellers result in reasonably priced consumer goods in the marketplace. And it has been useful for economists to think in terms of a common coin of utility; it allows them to compare the psychological value of desirable outcomes as different as a tasty meal with friends, a romantic vacation, and a Porsche Carrera GT.

Over the last few years, a new set of ideas has changed the face of economic theory, with the development of the field of behavioral economics. Challenging the classic model of rational man, behavioral economists have incorporated the insights of cognitive and social psychology—fields in which researchers have done a rich business demonstrating people's tendencies to use simplistic and irrational biases. In their popular book
Nudge
, for example, economists Richard Thaler and Cass Sunstein suggest, “If you look at economics textbooks, you will learn that
Homo economicus
can think like Albert Einstein, store as much memory as IBM's Big Blue, and exercise the willpower of Mahatma Gandhi.” Thaler and Sunstein distinguish between “Econs,” those classically rational individuals who make deeply reasoned decisions after a consideration of all relevant sources of information, and “Humans,” who make rather less omniscient decisions informed by limited cognitive heuristics and various irrational biases.

Perhaps the quintessential example of behavioral economics is Daniel Kahneman and Amos Tversky's demonstration of “loss aversion”—the finding that people are more psychologically moved by a loss of $100 than by a gain of an identical amount. To a rational economic mind, $100 is worth exactly $100. But Kahneman won a Nobel Prize for a body of work illustrating that this seemingly simple and rational equation ain't necessarily so. Along with Tversky, Kahneman demonstrated in various experiments that losing $100 has more psychological
impact than gaining $100 and that the typical human will pay more to ensure that he or she will not lose $100 than he or she will pay for an equal chance of getting another $100.

The infusion of cognitive psychology had a jolting impact on how we think about economics. I predict that adding evolutionary psychology into the mix will produce yet another seismic uplift in the terrain. I would argue that behavioral economists are only partly right in their focus on the limitations of human decision-making. Although I buy the distinction between Econs and Humans, I would distinguish between the behavioral economic view of “Humans as morons” and the evolutionary psychological view of “Humans as clever apes” (or let us call them “Evols”). Behavioral economists have focused on the proximate biases involved in heuristic decision-making, and I do not dispute that people often make quick-and-dirty decisions. However, the emerging evolutionary view is more in line with a position advanced by Gerd Gigerenzer and Peter Todd and their colleagues: that human beings use simple heuristics in ways that make us surprisingly smart.

In previous chapters, I mentioned three of my former graduate students—Jill Sundie, Norm Li, and Vlad Griskevicius—each of whom had studied economics before shifting their interests to evolutionary psychology. After thinking about the connections between ideas from economics and those from evolutionary psychology for several years, we have recently joined forces with Steve Neuberg and Jessica Li to advance the argument that many of people's seemingly irrational choices are actually manifestations of what we call deep rationality.

On the deep rationality view, decision-making indeed reflects psychological biases, but those biases are anything but arbitrary and
irrational. Instead, they are the outputs of mental and emotional mechanisms designed to maximize not immediate personal satisfaction but long-term genetic success. Furthermore, our view incorporates the notion of modularity in a central way. Instead of a single rational decision-maker operating according to a single set of utility-maximizing rules, this view presumes that all of us have a number of different economic subselves inside our heads. Each of our economic subselves pays attention to different costs and benefits and weighs them differently, in ways designed to deal with the most prominent threat or opportunity on our life's horizon.

If you have ever taken a course in either economics or social psychology, you have heard about the “prisoner's dilemma.” Here is how it goes: Imagine you are one of two crooks who have been arrested while trespassing at the scene of a potential heist, and that you are being held on suspicion for a string of burglaries. You have two options: remain silent (thereby
cooperating
with the other crook in evading prosecution) or confess to the district attorney (thereby
defecting
on your pact of silence with the other burglar). If only one person confesses, thereby providing the district attorney with solid evidence against the other, the one who confesses goes free. For the pair of you, the best outcome is if you both cooperate in remaining silent (in which case you will both get a short sentence for trespassing). But the decision poses a dilemma: If you remain silent and the other crook confesses, things will turn out really badly for you. From a purely economic perspective, the game is rigged so that the most rational decision is to defect. If the other crook keeps quiet, then you go free; if he defects also, you get a lighter sentence than if you had kept quiet. But it is a dilemma because, if both individuals make the purely selfish decision, they fare more poorly than if they had acted cooperatively.

FIGURE 11.1
A disappearing dilemma. The standard prisoner's dilemma is shown in the box on the left. In each box, the payoffs for prisoner A are above the diagonal, and those for prisoner B are below. For prisoner A, the best payoff always comes from defecting (choosing option D) rather than cooperating (choosing option C) (7 versus 6 if B cooperates; 3 versus 2 if B defects). The figure on the right shows that things change if the two players are brothers, who share half their genes. In that case, each prisoner's payoffs can be recalculated to include half his brother's gains. For the recalculated payoffs on the right, the best choice for each player is to cooperate, regardless of his brother's choice.

If you think in evolutionary terms, however, such dilemmas often disappear when the other player in the game is your brother or your child. Because you share half your genes with your child, your bank of inclusive fitness points gets to add half of your child's gains to your gains (and also to subtract half of his or her losses from your losses). In other words, the evolutionary banker in my head gives me a 50 percent rebate for every dollar I spend on a brother or a son.
Figure 11.1
shows how that works for one set of typical payoffs. It illustrates how a situation that would otherwise be a dilemma disappears if the players are close genetic relatives. Federico Sanabria, Jill Sundie, Peter Killeen, and I have explored how this works in more detail, and the bottom line is this: There are still some situations in which it pays for someone to defect on a close relative, but they are a much more limited set than those in which it pays to defect on a nonrelative. All the
standard economic models, of course, implicitly presume you are dealing with a nonrelative and can therefore ignore his or her payoffs and focus exclusively on your own.

Like a brother, my child shares roughly half of my genes. But there is another level of evolutionary math that makes it even easier for me to spend freely on my child. If my genes calculate the value of investing another dollar in my own mating success, it is not as likely to yield the same marginal utility as those genes would get if I invested that same dollar in one of my children. I already had sufficient resources when my son Dave went to college, so rather than investing more in myself, it made more sense to invest in him going to New York University, where he could develop his artistic film production skills instead of having to work in a factory. As a consequence, he was a more desirable fellow, who was able to attract college-educated women, and to produce two grandchildren with high IQs. My younger son, who is likewise turning out to be a highly intellectual guy, will also probably benefit from my continuing to invest in him as he grows up and develops his creative talents. My genes would gain no benefit if I made the more “selfish” decision to stop investing time and money in my sons and grandchildren, so that I could instead retire early, buy a fancy recreational vehicle, and learn to swing a golf club.

All this makes sense in terms of what evolutionary theorists call life history theory. According to this theory, which I discussed briefly in Chapter 7, any animal's life can be divided into two or three main phases, each one defined by a different set of investment trade-offs. The earliest phase is called somatic effort—when the animal invests mainly in building and maintaining its own body. The second phase is mating effort—when the animal invests time and energy into finding a mate. For some species there is (as we noted) a third phase, parenting
effort—when the animal shifts its time and energy investments toward raising its young.

At what age should an animal shift from somatic investment to mating effort? Should the animal waste time and energy on parenting effort? These are questions about economic trade-offs, and the answers depend on the expected payoffs. Young mammals are notoriously expensive to raise. They need a mother who is willing to carry them inside her body and then allow them to continue sucking out calories for months or years after they are born. So a typical mammalian female would gain nothing if she began reproducing too early, because until she has developed the physical capacities and behavioral skills to store enough calories for two, her young would not survive. Although a male could produce sperm much earlier, males typically wait even longer to switch to mating effort—until they have built a large enough body to effectively compete with the other, more mature males (on the efficient rule, Do not start competing until you have a reasonable chance of winning).

It all works as expected in our species. Human females typically are not capable of bearing young until they have reached their early teens. Boys typically do not reach puberty until a year or two later. As I discussed in earlier chapters, our species is one of a small minority of mammals in which the males do pitch in to help raise the offspring, because human babies develop slowly and have large, energy-hungry brains that make them especially needy.

From a life history perspective, early development—the somatic phase—is, as I noted in Chapter 7, akin to building a bank account. Reproductive effort is akin to spending that bank account. Different animals'life histories involve evolved strategies for spending that bank account on a schedule that will maximize genetic success, given the problems and opportunities that particular animal is likely to encounter. Thinking in terms of life history investments, splurging one's retirement money on a good time instead of reinvesting it in one's
grandchildren is only “selfish” at a proximate level. At an ultimate (evolutionary) level, our genes would regard it as self-defeating. So this perspective shifts the understanding of “rationality” from immediate personal payoffs to the much longer-term gene's-eye view.