A recent study found nerve fibres in the skin that cause pleasurable sensations – if the gentle stroking is done at a rate of 4-5 cm per second (1.5 to 2 inches per second). Pleasure was not felt if stroking was faster or slower. The fibres were found in “hairy skin” but not in the hands.
So, a slow gentle stroking of the arms or legs can be very calming and pleasurable, if you do it right. The rate that works is pretty slow – you may have to work at it to get it right. Think in terms of a longer stroke – say three seconds for 15 cm/
3 in6 in.
More info – BBC