Have you ever tried to tickle yourself?
If in reading this you just tried, the chances are it didn’t work, and you’d be in the majority of the population.
The inability of most people to tickle themselves comes from the fact that the brain predicts sensory consequences of our actions, and then cancels them out, Christian Jarrett explains for the British Psychological Society.
This may be a survival tactic, as it allows the brain to focus on external stimuli.
A team of psychologists from France conducted an experiment in which 397 students were asked to take the Schizotypal Personality Questionnaire, which identifies potential schizophrenia markers in people.
Of the pool of candidates, 27 scored highly and 27 scored low.
The findings showed that those with schizophrenic tendencies found the self-tickling condition more ticklish than those who scored low.
A symptom of the condition include delusions and hallucinations which can affect a sufferer’s senses - including their sense of touch - which could explain why they are able to tickle themselves.
The report read:
When considering a continuum ranging from the absence of a disorder to the full-blown symptoms of schizophrenia, our data provide a basis for understanding the illusions of control experienced by schizophrenic patients.
While the findings aren't conclusive, it does provide another nougat of knowledge about an illness that continues to baffle psychologists.