How childhood family structure influences fertility-orientated outcomes

Life history theory predicts that an unstable early family environment promotes a faster reproductive strategy. We test this prediction using data from the original Kinsey survey collected by the Institute for Sex Research: 1938 - 1963 in the US (n=16207). Broadly, for women our results support the prediction that absence of either natural parent from the childhood home will accelerate reproductive events such as age at first sex, first marriage, and first birth, although the effects are stronger for father absence than for mother absence. For men, the key may be the addition of a stepfather to the household as sexual behaviour was accelerated for men living with a natural mother and stepfather, but not with a natural mother only. For men we also find that mother (but not father) absence is associated with later age at puberty. These results withstand adjustment for socio-economic status, age, ethnicity, age at puberty (where applicable) and family size. These results support the hypothesis that early family environment influences later reproductive strategy. However, the different responses to the presence/absence of different parental figures in the household, and the different responses of the sexes, suggests that parental absence is not simply an indicator of an unstable early environment.