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My better nature

Alone with Darwin

Peter Singer

Making it alone

How selfish are human beings, really? It's a perennially fascinating question. In ancient Athens, if Plato is to be believed, Socrates debated it with Glaucon, who maintained that if only we could get away with it, we would all rob and kill to achieve our own ends. Socrates argued that only ignorance of the real nature of justice could lead a person to do that.

Just a century or so later, but on the other side of the planet, the Chinese sage Kao Tzu compared human nature to a pool of water: it can be made to flow to the east or to the west, depending on where one makes a breach. His opponent Mencius pounced on the analogy, saying that water nevertheless has a natural inclination, to flow downhill, and if human beings are allowed to follow their natural feelings, they, too, will incline to the good. In both West and East, these contrasting positions echo down the ages, each with its own proponents. But now that we have science, rather than mere anecdote, to answer such a question, shouldn't we be able to settle the issue once and for all?

Indeed, science has brought us closer to an answer. There is now a large body of relevant research. Some of it comes from the application of an evolutionary viewpoint to understanding the way we behave: a field known as evolutionary psychology. Initially, the idea that human nature is the product of evolutionary selection seemed to count against belief in the possibility of altruism. If we have evolved from beings who succeeded in the competition to leave more descendants in subsequent generations than their rivals, how could it be otherwise? Typical of this view is Pierre van den Berghe, who wrote in his 1978 text Sociobiology and Human Nature: "We are programmed to care only about ourselves and our relatives."

Yet this line of thinking conceals a crucial slide that makes the reasoning erroneous. Yes, it must be true that our genes lead us to act in ways that, for most of the evolutionary history of our species, led our ancestors to survive long enough to reproduce and to have offspring who survived and themselves reproduced - or, perhaps, to improve the survival prospects of others who carry the same genes, such as close relatives. But this does not mean that we care only about ourselves and our relatives. What the effect of our actions is, and what we care about, are two quite different things.

Here's a familiar example. The desire for sexual intercourse is one of the strongest human desires. That's entirely consistent with the evolutionary story, of course. If our ancestors had not had a desire for sexual intercourse, we would not be here. But that does not mean that we want to have sex in order to have children. A woman who thinks that she can rid herself of the attention of a persistent male by telling him that she is on the pill is going to be sorely disappointed. Most of us, most of the time, just want sex. That is the way evolution has programmed us. It works indirectly, on the basis of an evident link between what we are biologically driven to do and what will lead to our reproductive success.

There is no reason this indirect form of programming should not work in other areas as well. Consider something that is as universal and as basic to human beings as sex: co-operation. In every society known to us, humans form co-operative relationships with others. Some kind of norm of reciprocity - do good to those who do good to you and harm to those who harm you - is a strong candidate for being a culturally universal moral standard. Nothing surprising here: it is tough making it alone and so there are good reasons why humans will do better if they do co-operate with others. But does this prove that co-operation is just another form of selfishness, that we care only about our own interests and we co-operate in order to further those interests?

Not at all. Here's why.

Might is right & Darwin

Suppose that I am seeking someone with whom to develop a long-term co-operative relationship. Would I choose someone who decides to co-operate only in order to further her own interests? I would do better to avoid such a partner for, in every co-operative relationship, there may come a time when your partner will serve her own interests best by cheating you. Perhaps the pay-off from this one-time deception might be so great that it overwhelms the longer-term interests of co-operation. Or you may become old, or sick, and unable to reciprocate effectively. If I choose a partner who decides to co-operate only in order to further her own interests, when those moments come, she will cease co-operating.

So I will do better if I can distinguish the unselfish co-operators - those who have a sense of justice, or a sense of gratitude, or would feel bound by loyalty to their partners - from the calculating co-operators, who co-operate only because they see it as in their own interests. I will then form co-operative relationships only with the unselfish co-operators. If many other humans can make the same distinction and follow the same policy, then unselfish co-operators will do better than calculating co-operators. Evolution will lead to the survival of the most co-operative.

Admittedly, there is a further wrinkle to this story. It will now pay people to give the impression that they are unselfish co-operators, when in fact they are calculating co-operators. If they can succeed, they will get the best of both worlds. But this leads to a kind of arms race in which increasing skill at deception is matched by increasing skill at detection of deception. (And indeed, we do spend a lot of time trying to tell who we can really trust.) It is quite possible that, in the end, attempted deceivers don't do as well as those who really are unselfish co-operators. In contradiction to Pierre van den Berghe, they have been programmed to care about others, in this case those with whom they are in co-operative relationships. Of course, this does, objectively, improve their reproductive fitness, but that may be no more relevant to their motivation than the desire to reproduce is relevant to the interest men have in watching Britney Spears.

Some confirmation of the importance we place on preventing deception comes from a series of social experiments conducted by the Swiss researchers Ernst Fehr and Simon Gachter, published recently in Nature. They showed that people are prepared to punish those who freeload, seeking to reap the benefits of the co-operative activity of others, without doing their own share. Even when punishment costs the individual who is doing the punishing, most people are prepared to sacrifice their own interests in order to punish the cheats. Just as we sometimes help others from altruistic motives, so we may also punish cheats from altruistic motives. "Turn the other cheek" is not the only form of altruism and, from the point of view of reducing the number of cheats in society, it may not be the best.

The same can be said of attempts to explain altruistic behaviour by appeal to the "handicap principle", discussed by Amotz and Avishag Zahavi in their 1997 book with that title and newly fashionable among evolutionary theorists. Why does the male peacock have such a ridiculous tail? It doesn't help him fly. Doesn't so heavy a burden reduce his fitness? No, proponents of the handicap principle argue, it enables him to demonstrate to females what good genes he has. Even with the handicap of all those useless feathers, he can still survive! Hence the larger the tail - up to a point, anyway - the greater his fitness, since it enables him to attract mates.

Though there are some unresolved puzzles in this explanation - the demonstrated strength seems merely to compensate for the demonstrated handicap that the peacock's male descendants will also have to bear - the principle has been applied to altruism, giving the impression, yet again, that it somehow explains it away. Thus, Richard Conniff wrote in a recent article in Discover magazine: "Zahavi's handicap principle attempts to explain why babblers risk their lives by yelling at predators, why peacocks carry splendid but cumbersome tails twice the length of their bodies and even perhaps why Ted Turner gave $1billion to the United Nations."

But no-one familiar with Turner's reproductive opportunities could believe that giving away that amount of money was the best way for him to maximise the presence of his genes in future generations. It is even less likely that Turner himself believed this and that that belief led him to give the money away. The handicap principle may, if there is anything in it at all, tell us how it is that genes compatible with great acts of altruism do not get eliminated from the population. In that way, far from explaining away altruism, the handicap principle explains how altruism continues to exist.

Conniff's slip is part of a long tradition of misunderstandings of evolutionary theory. Shortly after On the Origin of Species appeared, Darwin wrote to a friend: "I have received in a Manchester newspaper rather a good squib, showing that I have proved 'might is right'." Darwin knew, of course, that he had done nothing of the sort, but people still grasp at evolutionary psychology in order to justify selfishness. It's important to stop the misinformation from reinforcing what the Princeton psychologist Dale Miller has called, in a recent essay in American Psychologist, "the norm of self-interest". As Miller argues, the fact that influential theories of human behaviour assert that we all act self-interestedly has an effect on how people exposed to those theories act.

Economics, of course, is a paradigm example of a study that assumes we behave self-interestedly. So, in a delightfully simple but telling piece of research, Robert Frank asked American university students at the beginning and end of a semester whether they would return a lost envelope with $100 in it. Students who had taken an economics course during the semester showed a greater shift away from returning the envelope than students who had taken an astronomy course.

Philosophers only interpret the world, the point is ...

In reality, we are often moved by motives other than self-interest and there is nothing in evolutionary psychology that would lead us to expect otherwise. But the hypothesis that we all act self-interestedly can become self-fulfilling. If we all think everyone else acts to further their own interests, we will feel foolish doing anything else.

The fact that we often act altruistically doesn't show that Mencius was right and our true nature is to be altruistic. There is no reason to assume a uniform human psychology in this respect. Some of us may find a niche in being successful freeloaders, and others may do better by continuing to co-operate even when it would pay them to desert their partners. The evidence we have to date suggests that Kao Tzu was nearer to the truth than Mencius. At least up to now, like water, human nature can flow either way.

That situation may not last. Marx once wrote: "The philosophers have only interpreted the world in various ways; the point is, to change it." He was not thinking of genetic change, but his comment will soon apply to that area, too. Within the present century, we are likely to learn how to change the genes of future generations to make human nature flow in the direction we want it to flow. That knowledge will bring an awesome responsibility, a responsibility that some think should never be exercised: the responsibility of deciding to improve human nature.

Will we allow individual parents to decide how they wish to change their children's nature? That is not likely to lead to more altruistic individuals. Or will we make the decision collectively, as a society, or even as a global community? If we do try to reach a collective decision, how will we decide what counts as an improvement? Should we try to enhance the capacities of humans to care about others? The prospect offers the greatest hopes of improvement in the human situation that we have ever known, but it will also pose the most daunting ethical challenge we have yet faced.


Peter Singer, a distinguished Australian philosopher and the author of several books on ethics, is Professor of Bioethics at Princeton University. This article was first published in the Sydney Morning Herald, 2 March 2002, and is republished with author's kind permission. For more information, go to Peter Singer Links.


Suggested citation

Singer, Peter, 'My better nature', Evatt Journal, Vol. 2, No. 2, March 2002.<>


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