Sir, – John FitzGerald is concerned by the effect of "assortative mating" on social inequality now that education matters more than land but, as Charles Darwin noted in his 1871 book Descent of Man and Selection in Relation to Sex, this has habitually occurred in all societies ("Choice of life partner has role to play in equality story", September 30th).
Further, the children of two clever parents will, on average be less clever and closer to the median than they are – just as two parents at the other end of the spectrum will have children who are cleverer than they are.
Sir Francis Galton, the first to apply statistical methods to heredity, described this phenomenon in 1886 as regression to mediocrity.
In the long run, assortative mating may matter less than Prof FitzGerald fears. – Yours, etc,
Dr JOHN DOHERTY,
Vienna.