Research suggests people with autism are prevented from gauging people's feelings because of visual processing problems.
According to researchers at Durham University, difficulties with identifying the body language of others presents day-to-day difficulties with social interaction for autism sufferers.
Findings published in the academic journal Neuropsychologia show adults with autism spectrum disorder (ASD) had difficulties seeing emotions, such as anger or happiness, in video clips of body movements without seeing faces or hearing sound.
The adults who performed the worst also struggled to detect the direction in which a group of dots moved coherently on a screen.
It is thought the problem occurs because of problems attributing mental states to others possibly because of different methods of processing basic visual information.
Dr Anthony Atkinson from Durham University's Psychology Department said: "People with autism are less able to use cues to make accurate judgments about how others are feeling. Our findings point to a difficulty in perceiving or attending to motion as a contributor to the problem of gauging people's emotions."