Here's something you might enjoy: a mass experiment which aims to test the emotional intelligence and intuition of people living in the UK has been launched at the Edinburgh Science Festival. Photographs of people smiling will be on display, with participants asked to identify which are genuine grins and which are fake. Everyone taking part will get feedback about their own intuitive abilities. You can also take part in the study online.

The BBC reports on a recent imaging study suggesting that the caudate nucleus (an area in the brain) receives or computes information about both the fairness of a social partner's decision and the intention to repay that decision with trust.