François Lelord said this quote

“ Basically, having a gift for happiness was a bit like being good at maths or games: it depended partly on the development of the brain after you were born, ad even before, but also on how your parents or other adults had brought you up when you were small. And of course on your own efforts and subsequent encounters.'Nature or nurture,' said the professor. 'Whichever way, the parents are to blame! ”