I think you meant: More unequal societies have more social problems (regardless of economic wealth).

I was very impressed with the talk. This has got some fairly epic ramifications for politics e.g. under this theory progressive taxes could make you better off even if they just buried the money in a big hole and set it alight. (Though he notes that you don't need regressive taxation to get this benefit, just equality by whatever means)

And since that kind of policy outcome will trigger the same old arguments I'd recommend that anyone intending to comment watch the actual 15 minute lecture first. It's thought-provoking wherever you find yourself on the political map with lots of potential for discussion that doesn't re-tread the same old arguments you've heard a thousand times before.

(edited for clarity)