Why do we pull faces when using our hands?

Our evolutionary past can answer why we screw up our face when playing music, writing or using our hands for other tasks. Dr Gillian Forrester, a psychological sciences lecturer from Birkbeck University of London, explains where these links between our hands and mouth came from.

Digital producer: Jack Burgess
With thanks to Gillian Forrester (Birkbeck, University of London).

Image: Child painting and pulling a face Credit: Getty Images.