The use of biometrics to verify identity is becoming well-established at airports, but the technology could find a wider application in the future to diagnose suspicious intent on the part of passengers and staff.

Defence Research and Development Canada (part of the Department of National Defence) released a paper in March 2011 describing how brain signals might be measured to distinguish hostile intent from everyday emotions.

Scientists aim to create standards to measure an individual's normal psychological and behavioural responses, before isolating the physiology of emotions such as fear or anger. In this way, 'biometrics of intent' could be employed to determine whether individuals displaying unusual behaviour in an airport are simply anxious or dangerous...