Being rich makes you mean: here’s proof

It’s all the rage these days to worry about the growing gap between rich and poor. Our fretting was fuelled by Capital in the 21st Century, by the French economist Thomas Piketty, which claims to show that over time this gap will grow inexorably. But we’ve been agonising about equality for aeons, and for aeons arriving at the same stand-off between rich and (relatively) poor.