Why we bite our nails

Nail-biting has long been considered a bad habit at best and a form of addiction at worst. Despite the social and potential health consequences, over 30 per cent of people do it. There are four main reasons for why people bite their nails:
               

It feels good | According to Tracy Foose, a professor of Psychology at UCSF School of Medicine, it feels ‘relaxing’ to bite one’s nails. Because of the unconscious enjoyment people get from it, biting nails can be comforting during a stressful situation, or might calm you down in the process of engaging in a difficult task.

You’re a perfectionist | Linked to the idea of comfort, research in the Journal of Behaviour Therapy and Experimental Psychiatry found that those who get irritable or angry quickly tended to be calmed by biting nails.

Genetic predisposition | One research paper argued that there may be a link between Onychophagia — habitual biting of the nails — and family history. Indeed, Shari Lipner, a professor at Weill Cornell Medicine argues that a third of nail biters have a member of their family who bites their nails also.

It’s a form of Obsessive Compulsive Disorder (OCD) | The last point is disputed. In 2012, the American Psychiatry Association listed nail-biting as a form of OCD (along with skin picking and hair pulling). However a large body of psychiatrists disagree with the decision, calling it an over-simplification of the disorder. Foose said, “As an anxiety specialist, I think that was an overreach for lumping disorders.”