Scientists Sakumi Iki and Ikuma Adachi recently spent a lot of time watching monkeys scratch themselves.
Self-scratching among non-human primates is known to indicate social tension and anxiety. The two researchers from Kyoto University, Japan, wanted to use this link to work out whether being anxious (and so scratching a lot) made their monkey subjects more pessimistic, or whether their pessimism was what drove their anxiety (and their scratching).
