Thu, May 18, 2017 - Page 9 News List

How cultural intelligence and language shapes human evolution

By Kevin Laland

Is there an evolutionary explanation for humanity’s greatest successes — technology, science and the arts — with roots that can be traced back to animal behavior? I first asked this question 30 years ago and have been working to answer it ever since.

Plenty of animals use tools, emit signals, imitate one another and possess memories of past events. Some even develop learned traditions that entail consuming particular foods or singing a particular kind of song — acts that, to some extent, resemble human culture.

However, human mental ability stands far apart.

We live in complex societies organized around linguistically coded rules, morals and social institutions, with a massive reliance on technology. We have devised machines that fly, microchips and vaccines. We have written stories, songs, and sonnets. We have danced in Swan Lake.

Developmental psychologists have established that when it comes to dealing with the physical world — for example, spatial memory and tool use — human toddlers’ cognitive skills are already comparable with those of adult chimpanzees and orangutans.

In terms of social cognition — such as imitating others or understanding intentions — toddlers’ minds are far more sophisticated.

The same gap is observed in both communication and cooperation.

Vaunted claims that apes produce language do not stand up to scrutiny: Animals can learn the meanings of signs and string together simple word combinations, but they cannot master syntax. Experiments also show that apes cooperate far less readily than humans.

Thanks to advances in comparative cognition, scientists are now confident that other animals do not possess hidden reasoning powers and cognitive complexity and that the gap between human and animal intelligence is genuine.

So how could something as extraordinary and unique as the human mind evolve?

A major interdisciplinary effort has recently solved this longstanding evolutionary puzzle. The answer is surprising. It turns out that our species’ most extraordinary characteristics — our intelligence, language, cooperation and technology — did not evolve as adaptive responses to external conditions.

Rather, humans are creatures of their own making, with minds that were built not just for culture, but by culture. In other words, culture transformed the evolutionary process.

Key insights came from studies on animal behavior, which showed that, although social learning (copying) is widespread in nature, animals are highly selective about what and whom they copy. Copying confers an evolutionary advantage only when it is accurate and efficient. Natural selection should, therefore, favor structures and capabilities in the brain that enhance the accuracy and efficiency of social learning.

Consistent with this prediction, research reveals strong associations between behavioral complexity and brain size. Big-brained primates invent new behaviors, copy the innovations of others and use tools more than small-brained primates do.

Selection for high intelligence almost certainly derives from multiple sources, but recent studies imply that selection for the intelligence to cope with complex social environments in monkeys and apes was followed by more restricted selection for cultural intelligence in the great apes, capuchins and macaques.

Why, then, have gorillas not invented Facebook, or capuchins built spacecraft?

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