Why do we bite nails?

Nail biting, also called Onychophagia is a bad habit. Actually this habit forms due to 3 reasons.

• Trigger
• Action
• Reward

So, a research suggests that the broken nail which is hurting can be a trigger. Biting and remove is the action. When the broken nail is taken off, the pain is reduced and we feel better. This is our reward. Now, if we again encounters small triggers like a broken nail, we repeat the same action to get rewards which gradually causes onychophagia. That is, we get a habit of nail biting