Biometrics are being used everywhere to recognise us. On this edition of CrowdScience we try out the tech that tells us apart. We find out just how unique our irises are and meet a man who can pick people out from a crowd of thousands just by analysing the way they walk.

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Presenter: Anand Jagatia

(Image: Fingerprints being looked at under a magnifying glass. Credit: Getty Images)