Philip Larkin's famous hypothesis - They fuck you up, your mum and dad.They may not mean to, but they do - has been corroborated by some recent happiness research, in two ways.

Andrew Clark and Emanuela D'Angelo show that our life satisfaction depends not just upon our own socioeconomic status, but also that of our parents. Other things equal, if two people have the same jobs and incomes, the one who is upwardly mobile is happier than the one who is in the same job as their parents.

This is probably because our parents' income acts as a reference group. Having rich parents raises our expectations and so makes us less content with a high income, whereas if you come form a poor home merely being able to pay the leccy bill without worry makes you happy.

But there's a second way in which our parents incomes affect our attitudes in adulthood, find Clark and D'Angelo. Our political attitudes, they find, "are some kind of weighted average of the individual's own status and parents' social status." Yes, richer people are more likely to vote Tory and oppose redistribution and state ownership. But for a given income, the upwardly mobile are more likely to be lefties. "Doing better than one's parents makes individuals more favourable to redistribution and more pro-public sector", they say. This could be because people who have done well from poor homes are more aware that state education, welfare benefits and the NHS can help people prosper in later life; Caitlin Moran's columns seem to be about little else.

If we put these two findings together, say Clark and D'Angelo, the implication is that "greater upwards mobility should make for satisfied Left-wingers." Which might help explain why there's so little of it.