Darwin Lecture, Robin Dunbar- part of Newcastle Insights Public Lectures Tue 11th Feb 2020.
Robin Dunbar is the academic who came up with Dunbar’s Number – the theory that we have on average 150 friends in our social circle. In the course of this talk covering the social bonding of primates and humans we learnt a little about the evolution of laughter.
Laughter is very primitive, coming well before the development of language. The great apes and chimps do it to show they are playing and not about to bite a limb off. The difference is that their laughter is a kind of pant on the exhalation with a vocalised inhalation. Thus sounding a little like ‘ha-huh-ha-huh’. Humans on the other hand only make the vocalised exhalation – ‘ha ha ha’. This prolonged exhalation puts stress on the chest walls. The body responds to this stress by releasing endorphins (endogenous morphine – pain relieving).
Another way that primates bond and produce endorphins is by grooming. It only works if the stroking is light and slow – 1-2 strokes per second. I tried this out with my Indian Head and Hand Massage techniques this morning and found my breathing deepened quite considerably. I had no idea I would learn so much information relevant to my work in a talk supposed to be about Darwin!!