Dr Josh Davis stumbled across so-called super recognisers while doing his PhD on police use of CCTV footage. He discovered there was a group within the police force that had an incredible ability to identify people from grainy footage and find them on the street. His research quickly shifted to trying to work out why some people can remember a face in extreme detail and for much longer than most. He's also devised a test that you can take to see if you are a super recogniser. If you are, you are in a group of less than one percent of the population.