Itching most contagious among nervous people
Nervous people are more likely than others to catch the itches by merely watching another scratch, a new study has found.
Like yawning and coughing, scratching is a behaviour that can spread from person to person.
Now researchers have identified the area of the brain responsible for the infectious nature of scratching, and found that some people are more susceptible than others.
Scientists from Hull and Sussex Universities instead found that contagious scratching was more strongly linked to neuroticism, or the tendency to have negative emotions.
"Almost everyone has felt that urge to scratch when watching someone else, but no one has ever really known why," the Telegraph quoted Dr Henning Holle, a psychologist who led the study, as saying.
"Highly neurotic people are known to be highly emotionally reactive and vulnerable to stress. We found that participants with higher neuroticism scores are also the ones that are more easily 'infected' by contagious itch."
The researchers asked 51 volunteers to fill in personality questionnaires, before scanning their brains as they watched video clips of people scratching or tapping parts of their arms or chest.
Their results, published in the Proceedings of the National Academy of Sciences journal, showed that itching was "contagious" among two thirds for/of the volunteers, and was more common among those with high levels of neuroticism but not those with high levels of empathy.
The findings "might reflect that the emotionally more stable participants, with low neuroticism scores, are less susceptible to contagious itch because they are better at suppressing the irrelevant itch sensation arising from observing someone scratch themselves", Dr Holle said.