Gregory Dawes reviews Michael Ruse's The Philosophy of Human Evolution in NDPR today. It's a balanced and thoughtful review, but I would like to query one prominent point in it.
Dawes reports that according to Ruse, "our evolutionary history, as embodied in our genetic makeup, imposes constraints on the range of behaviours that human beings may successfully undertake." In particular, "it may be that as a result of our evolutionary history "women want to spend time with their young children in ways that men do not" (p.196). It follows that we "should be cautious about utopian proposals for complete sexual identity" (p.196).
Now, first of all, we should be cautious about the term "constraint." Human nature is highly plastic, especially with regard to social behaviour. To say that men are constrained not to spend time with young children is far too strong. If Ruse says this—I haven't laid hands or eyes on the book, I am afraid, and so I don't know—then he goes too far. But suppose he had said something like: Men and women have genetic predispositions to behave in certain ways, but these predispositions are remediable by the right kind of education. Would Dawes object?
The idea that really disturbs Dawes is Ruse's plea that we "should be cautious about utopian proposals for complete sexual identity" (p.196).
how are we to understand the claim that women are particularly disposed to spend time in childcare and that this sets limits to our "utopian" schemes? It can only mean that there is no achievable social and political environment in which men and women would want to share childcare equally.
Surely this is wrong. Claims about dispositions are contextual and indeterminate about the circumstances in which they will be realized. But (on past acquaintance with his positions) I take Ruse to be committed to something like this: without remedial social education, and in the absence of need, men will spend less time with children than women. When he talks about utopian schemes, I take it he is talking about simply legislating gender equality, and he rightly says that we should be cautious about this.
There is a passage in Dawes' review that reveals something about how he came to his conclusions.
It may be, for instance, that a tendency to act altruistically has become widespread because it leads to a more effective transmission of one's genes, including that for altruistic behavior (p.160). But it does not follow that human beings do not act for genuinely altruistic motives, that is to say, out of a real concern for the wellbeing of others.
I take it that on the assumption that altruistic behaviour benefits "the selfish gene" in humans and other eusocial animals, it would be advantageous for these animals to evolve a predisposition to behave altruistically. In humans at least, such predispositions are expressed as desires. So on the selfish gene hypothesis, humans would naturally have "genuinely altruistic motives" and desires—i.e., real concerns for the wellbeing of others. Altruistic behaviour need not be realized by selfish motives.
Ruse is making a parallel point about gender. Animals of different sexes have different reproductive interests and this leads to competition among the sexes. This, in turn, leads to differences of behavioural dispositions and differences of untutored desires. The fact that human psychology is highly plastic doesn't undermine this basic fact.