Complex teaching and tools evolved together in humans, the study says

Ancient humans’ ability to master tools coincided with their ability to teach others, says a new study.

British researchers have conducted experiments designed to replicate the evolution of man-made tools over several hundred years with pipe cleaners and pieces of paper.

Experts found that participants who taught each other made the fastest progress, compared to those who simply had to imitate others or learn on their own.

The improvement of technologies and tools across generations, known as “cumulative cultural evolution” (CCE), has been the key to our success as a species.

But the origins of CCE, which led to world-changing inventions such as the Internet, aviation, and human spaceflight, are difficult to trace.

Once humans invented teaching, we probably took the first steps towards humanity by developing the amazing modern technologies we know today, the researchers suggest.

What we now know as CCE was alluded to by the English physicist Isaac Newton – a leading figure in the scientific revolution of the 17th century – when he said: “If I have seen beyond it is by standing on the shoulders of giants.”

This new study suggests that as early humans developed more complex tools, natural selection began favoring those with brains to be able to teach others.

“Humans have an unrivaled ability to pass knowledge down from generation to generation,” said study author Dr. Alex Thornton at the University of Exeter.

Traditional theories assumed that CCE required specialized processes, such as teaching, to convey information accurately, but this cannot explain why these processes evolved in the first place.

‘Our aim in this study was to test the hypothesis that these processes evolved gradually with an increasing dependence on complex tools.’

As part of the study, the researchers recruited 600 people to form “chain of transmission” groups, each consisting of 10 individuals.

Each group in the chain was tasked with making a simple tool – a boat made of waterproof paper – or a complex tool – a basket made of blue pipe cleaners.

Both instruments had to be judged on their ability to carry marbles and success was measured by the number of marbles carried by each instrument.

Each chain involved 10 “generations”, in which 10 versions of the tools were created, with improvements made in each generation by each person in the chain.

Each chain was also assigned one of three social learning conditions to adhere to while functioning: “emulation”, “imitation” or “teaching”.

In the emulation chains, the participants only saw the finished tool made by the previous person in the chain, while in the imitation chains, the participants watched the previous person as they created the tool.

In the teaching chains, meanwhile, each person talked to the previous tool maker in the group about how they attempted to make the tool.

In addition, the researchers performed an ‘asocial learning’ condition for 24 other participants, who had to build 10 successive versions of the tools with no chance of learning from others.

The researchers found that both the waterproof boat and the more complex brush basket improved with the creation of new versions.

However, the teaching provided only one advantage for the more complex tool: the pipe cleaner basket.

And while the simple waterproof boat tended to converge on a common design, the complex tools retained a design diversity.

“Simple and complex tools have generally improved over the generations, and for simple tools this improvement was roughly the same in all three study conditions,” said study author Dr Amanda. Lucas of the University of Exeter.

‘With complex tools, teaching has consistently led to greater improvements than other conditions.

“Teaching seemed to be particularly useful in enabling the transmission of new, high-performance designs.”

Teaching provided “ important advantages ” in manufacturing complex tools – however, the mere fact of having the opportunity to inspect tools made by others was also sufficient to generate improvements over other “ generations ”, satisfying the “ core criteria for CCE, ” the team said.

“The effects we saw were gradual, but the idea here was to look at the origins of cumulative cultural evolution and over many generations these gradual improvements would add up,” said Dr. Thornton.

“Our findings indicate an evolutionary feedback loop between toolmaking and teaching.

“This suggests that our ancestors could have started making modest cumulative improvements to simple tools without the need to teach, but as the tools became more complex, teaching started to become beneficial.

“The evolution of better teaching skills would in turn allow the production of even more complex and effective tools.”

The results are published in the Proceedings of the Royal Society B.