You would think, wouldn’t you, that if you were the child of a happy marriage, then you ought to have a better than average marriage yourself – either through some genetic inheritance or because you’d learnt from example? But it doesn’t seem to work like that. So perhaps you need the opposite example – to see mistakes in order not to make them yourself. Except this would mean that the best way for parents to ensure their children have happy marriages would be to have unhappy ones themselves. So what’s the answer?