Teaching is something we've all experienced. We may not always have enjoyed it, but there's no denying its importance in passing on information. Now, imagine trying to teach someone in silence. Could you still pass on that information effectively?
And no, you can't learn from reading. That's cheating.
Trying to teach without language seems like a tall order. As such, many have argued that the two go hand in hand. Language evolved to help us pass on information better, faster, harder, stronger.
However, just because it sounds right (pun intended) doesn't mean it actually is. Language is also useful for a whole bunch of other stuff, like socialising. Or reading Filthy Monkey Men. So, how can we figure out which of the many uses of language is the primary one (or ones) that drove its evolution?
Teaching seems like an obvious benefit
First, we need to address the elephant in the room. Yes, the ability to pass on information that could aid in your survival does seem like an obvious way language could aid in your survival. So why wasn't teaching considered the driving force of its evolution?
Well, despite how intuitive it sounds the evidence really wasn't there. Many experiments have shown language is important in learning, but only in modern settings. When trying to teach someone how to use ancient stone tools, language seems to become a lot less important. Prior to 2017, there were three studies on these sorts of "authentic" examples of teaching. 2/3 indicated you could learn just as well without verbal language.
Like I said, just because something sounds right doesn't make it so.
Studies on how modern people use language also seem to reinforce this. When we talk to each other, it's most often aimed at socialising, bonding and so forth. We devote relatively little of our linguistic energy to teaching. Plus. when you look at our ape relatives we see a similar pattern; with most of their interactions reinforcing social bonds rather than teaching.
In fact, some have inferred when language evolved based on those similarities. Primates traditionally bond through grooming, but can only groom one ape at a time. This places a limit on how big their groups can be before they can't groom enough people in the group to keep it together.
We live in groups larger than this limit, meaning we needed to develop something that could allow us to socialise a lot more efficiently. Enter language:
Case closed?
So, it looks like language-based teaching wasn't a big deal in the past but language-based socialising was. Is the matter settled? If you'd asked me 5 years ago I probably would have said yes. But there's an interesting pattern in this research which suggests something else is going on.
Like I said, a few experiments have investigated how important language is for teaching people how to use stone tools. Now, there's a lot of stone tools out there and each experiment picked a different one to study. Interestingly, those which examined newer, more complex tools found language was less important. People who learnt by watching were just as good at making Neanderthal technology as those taught verbally. Yet repeating the experiment with simpler Oldowan tools found language was better at teaching.
This seems completely counter-intuitive. Surely a more complex item would benefit from better teaching?
Well, it may be the case that the Neanderthal technology is just too hard to make. It can take years to learn how to make their tools. As such, even after a bit of teaching, both groups would still be rubbish. The impact of a small amount of better teaching is negligible. However, people can pick up Oldowan tools faster, so the impact of teaching becomes more pronounced so it can be detected in these studies.
In other words, the case isn't quite closed on the role of teaching in language evolution.
So this new study...
Palaeanthropologists wanted to try and solve this issue once and for all. So in 2017, they came up with a new, super-rigorous study.
Crucially, they tried to take into account all of these confounding factors which might be confusing earlier work. For example, they made sure everyone started with the exact same raw materials. And they were teaching them a method they knew could be learnt in the time frame studied.
Besides these tight controls, the experiment followed the pattern seen before. They divided up a bunch of Palaeolithic newbies into groups. They then taught them how to make the stone tools our ancestors created; varying the amount of language, imitation etc. that was allowed per class. After having their lesson, each group went off to try and make tools by themselves.
The results are quite interesting. When they tried to make tools during the lesson, all the groups did very well. However, when they went off by themselves things began to change, but not all in the same way.
For instance, the non-teaching "imitation-emulation" group made more attempts. However, they were much less successful at it than those who had verbal or gestural teaching. As a result, the taught groups would up making twice as many tools. Notably, this was true for both teaching groups. They both produced a similar increase in knapping skill.
What's more, the resulting tools were of a higher quality for the taught groups. This shows they also picked up an understanding of the method that the imitation group lacked.
So can we forget about sociality?
Based on all this, the researchers argue that this shows teaching was a big deal. As such, they conclude that these benefits are so significant that evolution wouldn't have ignored them.
Sure, socialising may have kicked off the evolution of language (and likely continued to influence it) but soon after the benefits of teaching would also begin to drive its development. But it's worth remembering there were likely many other influencers too. Evolution is a complex thing and it's likely many factors drove and influenced the evolution of language. This research simply adds one more to the pile.
Crucially, this also shows that this drive would have existed fairly early in our technological evolution. As such, the evolution of language may have similarly early. Maybe even ape-like Australopithecus was taking steps towards conversation.
Although it does have an interesting implication: if teaching is driving the evolution of language, could our focus on old languages be holding it back?
Clearly, it's time we took Shakespeare out of schools. Evolution demands it.
References
Dunbar, R. I. (2003). The social brain: mind, language, and society in evolutionary perspective. Annual Review of Anthropology, 163-181.
Lombao, D., Guardiola, M. and Mosquera, M., 2017. Teaching to make stone tools: new experimental evidence supporting a technological hypothesis for the origins of language. Scientific Reports, 7(1), p.14394.
Mesoudi, A., Whiten, A., & Dunbar, R. (2006). A bias for social information in human cultural transmission. British Journal of Psychology, 97(3), 405-423.
Morgan, T. J. H., Uomini, N. T., Rendell, L. E., Chouinard-Thuly, L., Street, S. E., Lewis, H. M., ... & Laland, K. N. (2015). Experimental evidence for the co-evolution of hominin tool-making teaching and language. Nature communications, 6.
