WHAT is the essence of you? What is it about you that makes you, well, you? These are no mere academic questions for armchair philosophers, but practical ones with real consequences.

Take a police artist sketching a suspect from an eyewitness description, or a profiler writing up the behavioural idiosyncrasies of a particular “perp”. These representations become tools in criminal investigations that often lead to arrests. If they fail to capture the essence of the person being sought, the wrong person may be arrested…

This article first appeared in New Scientist on 8 April 2017. To continue reading, click here (paywall).