If you have a pain, for example in your hand, and you cross your arms over the midline, it reduces the intensity of that sensation of pain by confusing the brain, scientists from University College London reported in the journal Pain.
The researchers think that conflicting information between the brain’s two maps – one for the person’s body and the other for external space – results in a reduction of pain sensation.
Full story: Crossing Arms Reduces Pain Intensity By Confusing The Brain