A third of us could have a mental health condition we don't know about. It is called misokinesia – the distress caused by watching people who fidget. Fidgeting is making small movements repetitively, especially with the hands and feet. People fidget because of nervousness or impatience. Misokinesia sufferers can have an "intense hatred" of people tapping their fingers, clicking a pen, or twiddling their hair. Misokinesia is like a condition called misophonia. This is a great dislike of other people's noises, such as heavy breathing, throat clearing or loud eating.

The study is from researchers in Canada. They interviewed 21 people in a misokinesia support group. The researchers concluded that misokinesia can be so distressing as to be "life limiting". Sufferers can have extreme feelings of rage, torture and disgust. One sufferer said: "If I see someone tapping their fingers on a desk, my immediate thought is to chop their fingers off with a knife." A clinical psychologist told the BBC that "violent images might pop into the head" of misokinesia sufferers. She said people can be triggered by the tiniest of things.