London School of Economics study, discussed here:
The study found that more intelligent people actually had lower life satisfaction the more frequently they socialised with friends - spending time with friends actually made them unhappy. But the researchers discovered that these highly intelligent participants actually spent more time socialising with friends.
Which is why they are more likely to be mentally ill. The expectation that one socialize creates mental conflict, but because the expectation is perceived to be natural the conflict is multiplied because the intelligent person is fighting against "nature", resulting in illness.
As the old saying goes . . .