Elliott Sober is Hans Reichenbach Professor and Henry Vilas Research Professor of Philosophy at the University of Wisconsin, Madison, where he has taught since 1974. Sober’s research is mainly in the philosophy of science, particularly in philosophy of evolutionary biology. His books include: The Nature of Selection - Evolutionary Theory in Philosophical Focus (1984), Reconstructing the Past - Parsimony, Evolution, and Inference (1988), Philosophy of Biology (1993), From a Biological Point of View (1995), and most recently, Unto Others - the Evolution and Psychology of Unselfish Behavior (1998), co-authored with David Sloan Wilson. Sober is currently doing research on the conflict between evolutionism and creationism, on the concept of scientific testability, and on methodological questions concerning how we go about attributing mental states to nonhuman organisms.

In this lecture, I want to provide a conceptual map of some of the main questions that have been posed about altruism. What biologists mean by “altruism” is not at all the same as what psychologists and ordinary people mean by the term. After explaining the difference between evolutionary and psychological altruism, I'll focus on the evolutionary concept and describe how it is possible for the competitive process of natural selection to lead altruistic traits to evolve. Then, I'll turn to the psychological concept and describe how it is related to, though different from, the concept of morality.

Evolutionary Altruism - A trait is said to be evolutionarily altruistic because of the effects it has on fitness. An organism's fitness is its ability to be reproductively successful; survival is relevant to fitness only to the extent that it promotes reproductive success. An altruistic behavior is one that enhances the fitness of someone else (the “recipient”) at some cost in fitness to the donor. Thus, a mindless organism can be an evolutionary altruist. Darwin thought that the barbed stinger of the honeybee is an altruistic trait -- the bee disembowels itself when it stings an intruder to the nest; the stinger keeps pumping venom even after the bee has perished, thus conferring a benefit on the group.

Psychological Altruism - An altruistic desire is an other-directed desire in which what one wants is that another person do well. Thus described, it is obvious that altruistic desires exist. The controversy about psychological altruism is not about whether such motives exist, but whether they are ultimate or merely instrumental. When we wish others well, do we have this as an end in itself, or do we care about others only because we think that how they do will affect our own welfare? The theory known as psychological egoism maintains that all ultimate motives are self-directed.

Psychological hedonism is one variety of egoistic theory. Hedonism claims that the only ultimate motives that people have are the attainment of pleasure and the avoidance of pain. The only thing we care about as an end in itself are states of our own consciousness. This special form of hedonism is the hardest one to refute. It is easy enough to see from human behavior that people don't always try to maximize their access to consumer goods. However, even when someone chooses a job with a lower salary over one with a higher one, the hedonist can interpret this choice as being motivated by the desire to feel good and to avoid feeling bad. Hedonists even think they can explain the most harrowing acts of self-sacrifice -- for example, the soldier who throws himself on a live grenade to save the lives of his comrades.

Altruistic Behavior - Rational Deliberation versus Evolutionary Game Theory

Game theory was first invented in mathematical economics. Only later was it brought within evolutionary theory. Perhaps the most famous game analyzed in game theory is the prisoners' dilemma. This problem was first formulated as a question about individual decision making; this is the form in which I'll explain it. Then I'll show how the problem was reformulated in evolutionary theory. The solution accepted in the one context isn't the same as the solution that makes sense in the other. Understanding this is the key to seeing what it takes for altruism to evolve.

Cultural and Genetic Evolution - Although biologists modeling the evolution of altruism usually assume that different phenotypes correspond to different genes, this assumption is not needed in an evolutionary model. If parents and other adults in a group transmit their traits to the next generation by teaching, altruism can evolve by cultural evolution. Evolution by natural selection requires a mechanism of inheritance, but the core idea here is just that offspring resemble their parents.

Altruism and Morality - Altruism, whether evolutionary or psychological, often strikes people as a good thing. This is often true, but altruism's dark side needs to be held clearly in view if we are to understand the moral dimensions of altruism and also its evolutionary and psychological character.

The process of group selection does not eliminate competition from the evolutionary process, but merely transposes it up one level. Group selection can promote within-group niceness, but it also can promote between-group nastiness.

There is a similar dark side to psychological altruism. Altruistic motivation can underwrite evil. The easiest way to see this is to realize that being nice to someone can involve being nasty to third parties. If Alan cheats Beth at cards because he wants to give the money to Carol, we may decide that his dishonesty was altruistically motivated and morally wrong.

There is another sort of separation we must effect between altruism and morality. An altruistic concern for specific others is not the same as the acceptance of a general moral principle. If I want my children to prosper, it is a separate question whether I want all children to do well, or think that all parents should help their children. Moral principles are general and impersonal in what they say.