Today is April 1st, a good day to talk about laughter and how it may have been one of the most important forces in human evolution. You see, laughter may well have been the precursor to language, allowing us to develop modern communication; arguably one of the key components to our current success1. It might sound a bit silly, but don’t have to worry about me pranking you. Here in Liverpool it’s past noon; the traditional cut off point April fools’ pranks (although I’m fairly convinced this is just a rule concocted by parents who wanted an early end to their children’s’ shenanigans).
Flimsy justifications for discussing this research aside; the role of laughter in language evolution is an idea that has its roots in the social brain hypothesis. For those who haven’t crawled back through all my archives (shame on you if you haven’t), the SBH is one of the most popular explanations for why our brains are so big. It argues that living in large groups was really useful for our ancestors as they protected us from predators; but these large groups are intellectually demanding, requiring us to remember who everyone is, how they’re connected, who has alliances, who we can trust etc. The demands of group living drove the evolution of big brains2.
But living in large groups caused another problem: socialising began to take up too much time. Studying modern primates reveals that if you start spending more than 20% of your time bonding with others then it begins to eat into your time budget for gathering food, sleeping etc. and your chances of survival drop rapidly. Yet the groups our ancestors were supposed to be living in were so big that picking the fleas off each other – the tactic modern primates use for bonding – would have taken too much time to sustain relationships with everyone. After all, you can only really groom one person at a time. For our larger groups to flourish our ancestors had to develop a much more efficient way to bond3.
And this more efficient form of bonding was laughter1. Actually, it was originally argued that it might have been proper language. After all, chatting with someone is a great way of bonding. You can talk to multiple people at once, rapidly share personal information3. But this creates a bit of a paradox. If language evolved to help us socialise then where did it come from in the first place4? So the hunt was on to find some sort of language precursor which could help our ancestors socialise more efficiently. And a couple of years ago Robin Dunbar – the original author of the social brain hypothesis – hit upon the idea that it was laughter1.
Now before you laugh at this idea (haha wordplay. If you laughed we are now bonded) there is a fair bit of support for it. It triggers the same sort of endorphin response that primates get when groomed, so does result in bonding1. Socialising via speech also activates a similar hormonal response5. It can involve multiple people at once, so could be the more efficient way of socialising our ancestors needed. And perhaps most interesting, it is a cross-species behavior. Chimpanzees, our closest living relatives, also laugh; and they do so in the same sorts of situations as we do, like when they play together or are tickled1 (although personally I don’t tend to bond with people that tickle me, instead developing a desire to kill).
Chimps lack the fine control over their breath humans have, so their laughter isn’t as loud as ours
So laughter could allow our ancestors to socialise more efficiently and wouldn’t require the evolution of any new traits. They would just have had to start laughing more. And once that got going, one could imagine a set of circumstances where these noises became more varied depending on situations, conveying more information and developing into a sort of proto-language.
But before you devote your life to rehearsing jokes in the hope of improving your social standing, there are a few problems with the idea of “laughter to language”. Most notably, there are no chimp comedians and they don’t find slapstick particularly appealing. It’s hard to ensure that laughter is going to occur in chimps, so how could our ancestors guarantee that enough funny things would occur for the resulting laughter to sustain their social relationships. If there are a few days where nothing amusing occurs, would the group fall apart and early humans go extinct?
Perhaps then we’re looking at the problem the wrong way. What if it wasn’t laughter that was a key evolutionary development, but our sense of humour? If our ancestors began to find more things funny then they would laugh more, and it could be relied upon as a way to socialise. A Homo erectus tries to make a stone tool and hits themselves on the thumb; and finding this funny is a profound change in our mindset that allows the whole group to bond. This might not have resulted in language – what with the different underlying mechanisms and all – but maintaing large groups was critical to our survival; and maybe it was humor that made this possible.
So if you’ve been subjected to a particularly horrible prank this April fools, perhaps you can take some solace in the fact you’re taking part in a proud heritage that helped humanity become so successful. Or at least, what the speculation of a handful of researchers indicates might have played a partial role in helping humanity become so successful.
References
- Dunbar, R. I. M. (2012). Bridging the bonding gap: the transition from primates to humans. Philosophical Transactions of the Royal Society B: Biological Sciences, 367(1597), 1837-1846.
- Dunbar, R. I. (1998). The social brain hypothesis. Brain, 9(10), 178-190.
- Dunbar, R. I. (1997). Groups, gossip, and the evolution of language. In New aspects of human ethology (pp. 77-89). Springer Us.
- Bickerton, D. (2007). Language evolution: A brief guide for linguists. Lingua,117(3), 510-526.
- Seltzer, L. J., Ziegler, T. E., & Pollak, S. D. (2010). Social vocalizations can release oxytocin in humans. Proceedings of the Royal Society B: Biological Sciences, 277(1694), 2661-2666.
