Stove Selection Theory | Mises Institute

[Darwinian Fairytales: Selfish Genes, Errors of Heredity, and Other Fables of Evolution by David Stove (Encounter Books, 1995; xv + 345 pp.)]

In a number of recent columns, I’ve been concerned about whether an evolutionary argument based on natural selection undermines objective ethics. If the best explanation for our moral beliefs is that they are adaptations that were best fitted to help us survive, why isn’t this enough? Why do we need to add that these beliefs are also objectively true? Indeed, the philosopher Sharon Street argues that it would be extraordinarily lucky if the beliefs that natural selection implanted in us turned out to coincide with the objective truths. Isn’t it then rational to drop these allegedly objective truths altogether?

How should those who accept objective truth in ethics respond to the evolutionary argument? Robert Nozick, as I discussed in an earlier column, argues that the beliefs that helped our ancestors to survive meet the standard criteria for objectively true moral beliefs. For example, the belief that you shouldn’t, in normal circumstances, start fights with people who live in your community aids survival and also seems objectively true.

As those of you who read my column last week would expect, David Stove takes a more radical approach. To our question, “Doesn’t an evolutionary argument based on natural selection undermine objective ethics?” Stove’s answer is that the evolutionary account is absurd and should be rejected. We need one clarification to understand how radical Stove’s position is. He is not arguing like this: “The evolutionary account is inconsistent with our ethical beliefs. But we know that our ethical beliefs are true, or at least we think that the reasons for acceptance of these beliefs outweigh the reasons for acceptance of the evolutionary account. Therefore, we ought to reject the evolutionary account.” Rather, Stove contends that the evolutionary account is, on its own terms, false and absurd.

Stove is not a supporter of Intelligent Design. On the contrary, he is a hardheaded atheist. He also accepts human evolution from hominid ancestors. His sticking point is natural selection, so far as this applies to human beings, both in Darwin’s original account of this concept and in the modern theory of kin selection. (In this column, I’ll confine my discussion to the latter).

The problem that kin selection tries to solve is this: Sometimes, people help others in a way that impedes their own survival. For example, people sometimes put their own lives at risk or even sacrifice themselves to save people to whom they are related. Wouldn’t natural selection eliminate people with a tendency to do this?

Kin selection theory denies that natural selection does this. According to it, what natural selection aims to preserve is not individual people as such but rather their genes. If you pass on to your descendants more of your genes than your evolutionary rivals, you will prevail in the struggle for survival. The key point in the theory builds on the fact that genetic similarity isn’t confined to parents and their children. You share half your genes with your parents but also half your genes with your brothers and sisters and lesser amounts with more distant kin.

Stove says that this theory leads to obviously false empirical predictions. The cases of altruistic sacrifice in the actual world are radically different from what the theory says they should be. As Stove puts it:

If the altruism of parents towards their offspring is due to their sharing half of their genes with each offspring, then filial altruism ought to be as common and strong as parental altruism. For if your offspring has half of your genes, then it is also true that you have half of your offspring’s genes. Yet in our own species, as everyone knows, parental altruism vastly exceeds filial, both in commonness and in strength. . . I am completely unable to explain Hamilton’s silence about the universal asymmetry, where his theory required symmetry, between filial and parental altruism in sexually reproducing species. (W.D. Hamilton was the founder of kin-selection theory.)

Stove acknowledges that there is a “patch” to this objection, but he thinks the theory is still in trouble:

The patch goes as follows. A parent is necessarily older than its offspring, right? An offspring therefore has more of its reproductive career ahead of it than a parent of it has, right? So a selfish gene, always on the lookout to maximize the representations of its copies in the population, will in general prefer to invest in an offspring rather than in its parent, and will dispose an organism which carries it to honor its sons and daughters rather than its father and mother. . . The shared genes theory of kin altruism suffers from other punctures which no attempt has ever been made to patch, for the simple reason that they are, in the eyes of the theory’s adherents, not punctures but beauty spots. One of these concerns identical twins. Such twins have, of course, all of their genes in common. Their mutual altruism must therefore, according to the inclusive fitness theory, be 100 percent. This reductio ad absurdum of the theory is willingly embraced, in fact mistaken for a successful prediction, by all sociobiologists.

Stove raises a deeper objection to the theory. Why should a particular gene, taken as a physical entity on a chromosome, care about reproducing other genes that are qualitatively identical to it? (I’m here ignoring problems of personifying genes as wanting things, which Stove also discusses. Defenders of the theory like Richard Dawkins acknowledge that such talk is metaphorical but think it can be “cashed out” in literal language. Stove is skeptical.) But the point is best taken in Stove’s own words:

It is true, of course, that if M [a molecule or group of molecules] is a gene, and brings the replica into existence. . .then there is a larger number of this kind of gene in existence at the later time than there was at the earlier. But this proposition implies nothing whatever about benefit. Indeed, it is not even a truth of biology; it is only the trivial truth of arithmetic, that two is a larger number than one. It is equally true that if M is a water molecule, and remains in existence while its replica is synthesized in some laboratory, then there is a larger number of that kind of molecule in existence at the later time than there was at the earlier. But it would be evidently nonsensical, in this case, to speak of anything having benefited by the change. And it is no less evidently nonsensical in the case where M is a gene instead of a water molecule, and produces the replica itself.

I wish that Nozick were here to respond to Stove: a debate between these two philosophers who, by the way, thought very little of each other, would be valuable. At the very least, Stove has given us much that is worth thinking about.