Rejoinder to Jorge L. Ahumada's Response

Contrary to Ahumada's assertion about robust population growth in Europe, “The birth rate dropped precipitously across Europe from the 1870's onwards. In Austria the rate dropped from 34.5 per 1000 to 24.9 to 22.6 ” (McLaren, , p. 514, cited in my article). But why quibble about such picayune details? That (some sectors of) Western society went from Victorian attitudes about sex to an entirely different sexual landscape today is undeniable; and, as I hope I made clear in my response to Ahumada's paper, he and I are basically in partial agreement about the contemporary ‘trivialization’ of sexuality.

It is certainly the case, as Ahumada says, that the benefit to the gene pool is not what psychologically motivates people to have sex most of the time; but that genetic benefit is nonetheless its frequent result, and also therefore (to a large extent) its evolved reason for existing and physiologically providing pleasure to the organism. (This, by the way, is Darwinian, not Lamarckian, reasoning.) Ahumada here fails to understand Tinbergen's now canonical distinction between proximate and evolutionary perspectives, and between phylogenesis and ontogenesis - something Freud apparently understood well before Tinbergen wrote.

Ahumada has what I would view as an outdated and inadequate grasp of evolutionary theory. Therefore he both misunderstands and misrepresents what I mean by dual inheritance. To begin with, he denies that culture is ‘inherited’, but this is simply wrong. It is obviously passed from one generation to the next both in the form of ‘social learning’ (which many animals can also do) and in the form of signs and symbols, of which the key exemplar is language - something animals do not possess. This means that humans, in the course of their ‘autopoesis’ or self-formation, are guided by instructions encoded in two different media, one in strands of the molecule DNA, and one in the form of linguistic and other information passed not via sexual intercourse, as is