You know how when you see someone scratching an itch it makes you feel itchy, too? That’s perfectly normal, a new study says — especially for those who tend to be on the neurotic side.
Research conducted by psychologists at the universities of Hull and Sussex in Great Britain and published online Nov. 12 in the Proceedings of the National Academy of Sciences turned up some fascinating information about itching. The researchers rounded up 51 healthy adult volunteers, had them complete personality-trait surveys and then had them watch some videos. The videos showed people either scratching various parts of their upper bodies or merely tapping those areas with their fingers. Participants reported on whether they felt an urge to scratch — and if so, how strong — when viewing each video. They also were videotaped as they watched, so the researchers could document how often they actually scratched themselves.
The majority — 64 percent — scratched themselves at least once while watching images of others scratching themselves. That indicates that itching may be more “socially contagious” than yawning (which 40 percent to 60 percent of people will do when they see someone else yawn, other research has found) and laughing (47 percent), the study notes.
The study also revealed that seeing someone else scratch triggers activity in the same parts of the brain that are activated when a person has an itch himself. The researchers learned this by capturing functional MRI scans of participants’ brains when they viewed videos of people scratching.
Alas, it is apparently not empathy for others that makes us share the urge to scratch. It is neuroticism. People in the study whose personality profiles included high degrees of that trait, which is defined as “the tendency to experience negative emotions,” were more likely than less-neurotic participants to report feeling itchy when watching others scratch.
Beyond being just plain interesting, the study’s findings could help scientists understand the roots of persistent itching reported by people who don’t have a skin condition that causes such an itch, the authors suggest.