In the early days of the last US elections, Hillary Clinton’s campaign was accused of deliberately darkening Barack Obama’s skin in a TV ad. The implication was that by highlighting Obama’s “blackness”, Clinton’s camp was trying to exploit negative associations that voters might have with darker skin. But you don’t need editing software to do that – a fascinating new study suggest that people literally change the way they see a mixed-race politician, depending on whether the candidate represents their own political views.

Liberal American students tend to think that lighter photos of Barack Obama are more typical of him, while conservatives think he’s best represented by darker photos. You can see this effect even after adjusting for any racial