In a recent study of whether religious parents tend to produce more children than the average, and published in the Proceedings of the Royal Society B, it was found to be true. This study depended on data from 3.6 million women of various faiths in 32 countries.
The authors of the study speculate that the reason for this might include (a) greater marital happiness and stability; (b) a lower likelihood of using contraception; and (c) a greater likelihood of holding traditional views of marriage and childbearing.
Because data for (a) and (b) were not known for the 3.6 million women then they must remain speculative or, at best, only by-products of (c) which is really a catch-all and is only another way of saying that “traditional views of marriage and childbearing” belong to the past — that is, to the agricultural era before urbanisation.
And, of course, all parents in an agricultural society — usually without state, or even local, welfare in old age — have got to produce more than merely a replacement number of two children per family in order to ensure that there’ll be enough children to look after them when they become too old to look after themselves.
The one exception that the researchers discovered does, in fact, prove the rule about agricultural culture being the basic reason. This was of Brazilian women, almost all of whom are Roman Catholics — the faith in which large families are greatly encouraged — who turn out to have small families.
These are on the cusp of rapidly changing from an agricultural society to that of being an urban one. Whether the parents are living in poverty in a favella or not, very many second and third children are simply not conceived for the sake of being able to afford a television set and a washing machine.