Family and fertility: kin influence on the progression to a second birth in the British Household Panel Study

Summary

Particular features of human female life history, such as short birth
intervals and the early cessation of female reproduction (menopause),
are argued to be evidence that humans are ‘cooperative breeders’, with a
reproductive strategy adapted to conditions where mothers receive
substantial assistance in childraising. Evolutionary anthropologists
have so far largely focussed on measuring the influence of kin on
reproduction in natural fertility populations. Here we look at the
effect in a present-day low-fertility population, by analysing whether
kin affect parity progression in the British Household Panel Study. Two
explanatory variables related to kin influence significantly increase
the odds of a female having a second birth: i) having relatives who
provide childcare and ii) having a larger number of frequently contacted
and emotionally close relatives. Both effects were measured subject to
numerous socio-economic controls and appear to be independent of one
another. We therefore conclude that kin may influence the progression to
a second birth. This influence is possibly due to two proximate
mechanisms: kin priming through communication and kin assistance with
childcare.