Highly read on www.cell.com 15 May—14 June

The size of certain brain regions offer clues to a person's political leaning, according to Ryota Kanai at University College London and his colleagues.

In brain scans of more than 100 university students, self-reported conservatives had above-average volumes of grey matter in the right amygdala, whereas liberals had more of the grey stuff in the anterior cingulate cortex (ACC). This structural pattern fits with previous work that linked liberalism to high activity in the ACC, which is thought to help the brain sort out conflicting stimuli, as well as research correlating conservatism with higher levels of aggression under threat, an emotion probably processed by the amygdala.

Results aside, perhaps the reason that this paper was so often downloaded is that one of the co-authors is actor Colin Firth. Firth prompted the team to do the study for a BBC Radio 4 programme.

Curr. Biol. 21, 677–680 (2011)