The limits to low fertility: A biosocial approach

In light of 30 years of below-replacement fertility in many industrialized societies, demographers are asking whether fertility could drop even furthe r, or whether there is a "floor" below which it will not fall. A key unansw ered question is whether there may be a variable biological component to fe rtility motivation which ensures that we continue to reproduce. Drawing on evidence from evolutionary biology, ethology, quantitative genetics, develo pmental psychobiology, and psychology, the article argues that our evolved biological predisposition is toward nurturing behaviors, rather than having children per se. Humans have the unique ability to be aware of such biolog ical predispositions and translate them into conscious, but nevertheless bi ologically based, fertility motivation. It is likely that we have already r eached the limits to low fertility since this "need to nurture," in conjunc tion with normative pressures, ensures that the majority of women will want to bear at least one child. A sketch for a biosocial model of fertility mo tivation is outlined.