The Daily Mail reports that 'almost half of young women aged 18 to 25 would prefer to have large breasts than high intelligence.' This raises four issues about the role of preferences in the social sciences:

1. Is the survey reliable? It's possible that this number is downwardly biased because some women would not want to admit to being so shallow as to prefer to embiggen their norks than their IQ. This raises a general issue about the usefulness of survey data. Ideally, we would corroborate such data against other evidence. This is why happiness researchers, for example, correlate self-reported well-being against other indicators (pdf), such as the opinion of friends, tendency to smile and vulnerability to mental ill-health or cardiovascular disease.

2. Is this preference irrational? There's some evidence that the returns to ability are low (pdf), especially for a given level of education, and have fallen (pdf) recently. There's also the possibility that there are diminishing returns to IQ; whereas moving from an IQ of 80 to 100 might lift one out of poverty, moving from smart to very smart has less effect. Malcolm Gladwell has written:

The relationship between success and IQ works only up to a point. Once someone has reached an IQ of somewhere around 120, having additional IQ points doesn't seem to translate into any measurable real-world advantage (Outliers, p79)

If this is the case - and it's controversial (pdf) - then it is quite rational for many women to be less keen upon improving their IQ than enlarging their breasts, especially if the latter boosts their confidence.

3. Are pro-social preferences necessarily a good thing? It's highly likely that the returns to IQ, insofar as they exist at all, are appropriated privately; social returns to education are notoriously hard (pdf) to find, and it's reasonable to suppose the same is true for the returns to IQ. But bigger norks have an obviously positive externality.

Women's preference for bigger norks over a higher IQ is, therefore, is a pro-social preference. Which raises a paradox. It's common for the left to believe that pro-social preferences are a good thing - hence their animosity to capitalists' 'greed'. But in this case, I suspect many do not believe this. There's a reason for this'

4. Does this show the prevalence of endogenous preferences? There are two ways this might be the case. Feminists will allege that the preference for larger norks represents an adaptation to a body image fostered by patriarchal forces. But there's another mechanism too. Embiggening norks can be easily done by surgery, whereas it's much less obvious that IQ can be so malleable in adults. A preference for bigger norks might therefore be an example of how people want what's available.

This matters, because the idea of endogenous preferences undermines a lot of welfare economics and, indeed, the very case for democracy. The issues here, then, are rather important.