Why we laugh

Why do we laugh? What is laughter’s purpose? What does it profit us? Why is it built-in and not learned? Does it say something about our humanity?

The Evolutionary Origin of Laughter:

The social brain hypothesis is that language evolved as a way of establishing and strengthening bonds with larger numbers of individuals in a shorter a period of time. Conversation can easily include up to 10 individuals and would have been a skill that dramatically improves the fitness of these individuals for life in the group.

Laughter is simply an extension of this process, say Marijuán and Navarro. Since the act of talking limits the number of individuals who can take part in a conversation, laughter is a method that individuals use to signal their participation in larger group chats. And the result of all this extra bonding is that the larger group, and hence the individuals within it, flourishes. 

Laughter is a similar kind of release [to that of blushing], say Marijuán and Navarro. The intellectual momentum that builds up during conversation needs to be relieved, either through verbalisation or some other mechanism.

Marijuán and Navarro’s suggestion is that this other mechanism is the channelling of excess cortical excitations to parts of the brain responsible for vocalisation. But without anything specific to say, the result is the kind of panting and cackling that we call laughter. That’s why it is built in. This social significance of this behaviour is the thing that has evolved, not the activity itself. 

So laughter (and by extension fun and playfulness — not just “intellectual momentum”) is intimately linked to bonding and bonding to the success of social groups. In my opinion, this is why it is good and healthy for adults to play. And maybe we need just a little help in the form of creative technologies to get us there.