Whether by compelling us to follow the latest fashion or to practise good table manners, the company we keep is known to have a strong influence on our behaviour. But the effect of society, it seems, can reach even deeper. Joel Levine and colleagues have found that internal biological clocks - those that regulate our sleeping rhythm, for example - can be reset by social interactions. Although this work was done in fruitflies, and the external cues were found to be olfactory ones, it is possible that the clocks of other species respond to the social environment in a similar way. Link