88. INTELLIGENCE — A

David Robson is a senior journalist at BBC Future. He wrote an article that is part of a BBC Future series about the long view of humanity, which aims to stand back from the daily news cycle and widen the lens of our current place in time. His research and findings raise important issues about the state of our intelligence. Robson explores what the state of our intelligence means for not only being what our potential calls us to be, but also the future of our civilization. This and the next post draw heavily from his article and will point to some implications of Robson’s work.

“You may not have noticed, but we are living in an intellectual golden age. Since the intelligence test was invented more than 100 years ago, our IQ scores have been steadily increasing. Even the average person today would have been considered a genius compared to someone born in 1919 — a phenomenon known as the Flynn effect.”

“The most recent evidence suggests that this trend may now be slowing. It may even be reversing, meaning that we have already passed the summit of human intellectual potential.”

“Let’s begin by exploring the ancient origins of human intelligence, from the moment our ancestors began to walk upright more than three million years ago. Scans of fossil skulls … were about 400 cubic centimeters — just a third the size of modern humans’. That comes at a serious cost. The brains of modern humans consume around 20% of the body’s energy, so our bigger brains must have offered some serious benefits to make up for those excess calories.”

This brain boost was likely a response to the increasing intelligence demands of group living. As our ancestors began to congregate in bigger groups, there was a need for protection against predators and the pooling of resources to spread out some of the risks of living in a changeable environment and also to provide shared childcare.

Living with other people came with challenges. “You need to keep track of each person’s personalities, their likes and dislikes, and whether or not they can be trusted with gossip. And if you are working on a group activity, like hunting, you need to be able to follow what each member is doing as you coordinate your activities. For humans today, a lack of social understanding causes embarrassment; for our ancestors, it was a matter of life or death.”

“The larger social groups would have allowed members to share ideas and build on each other’s inventions, resulting in new technological and cultural innovations, such as tools that could improve the efficiency of hunting. And for that to work, you need to have the intelligence to observe and learn from others — providing another push for greater brainpower.

“By around 400,000 years ago, [our brains] had reached around 1,200 cubic centimeters — just a shade smaller than the brains of modern humans, which are around 1,300 cubic centimeters. When our ancestors left Africa around 70,000 years ago, they were smart enough to adapt to life in almost every corner of the planet. The astonishing cave art suggests they were fully capable of thinking about huge cosmological questions — including, perhaps, their own origins.”

“It was only 100 years ago … that scientists first invented the ‘intelligence quotient’ to measure someone’s intellectual potential. Their success relies on the fact that many cognitive abilities are correlated. … For this reason, IQ is thought to reflect a ‘general intelligence’ — a kind of underlying brainpower.”

“[IQ tests] are not a perfect measure, by any means — and many other factors will also shape your success — but in general they do show a meaningful difference in people’s capacity to learn and process complex information.”

“When the researcher James Flynn looked at scores over the past century, he discovered a steady increase — the equivalent of around three points a decade.” Multiple environmental factors contribute to this increase.

“Perhaps the best comparison is our change in height: we are 11cm (around 5 inches) taller today than in the 19th Century, for instance — but that doesn’t mean our genes have changed; it just means our overall health has changed.”

“Improved medicine, reducing the prevalence of childhood infections, and more nutritious diets, should have helped our bodies to grow taller and our brains to grow smarter, for instance.”

“Our societies have also seen enormous shifts in our intellectual environment, which may now train abstract thinking and reasoning from a young age. In education, for instance, most children are taught to think in terms of abstract categories (whether animals are mammals or reptiles, for instance). We also lean on increasingly abstract thinking to cope with modern technology. Just think about a computer and all the symbols you have to recognize and manipulate to do even the simplest task. Growing up immersed in this kind of thinking should allow everyone to cultivate the skills needed to perform well in an IQ test.”

However, “there is evidence that we may have already reached the end of this era — with the rise in IQs stalling and even reversing. If you look at Finland, Norway and Denmark, for instance, the turning point appears to have occurred in the mid-90s, after which average IQs dropped by around 0.2 points a year. That would amount to a seven-point difference between generations.”

“One possibility [for this trend] is that education has become slightly less stimulating than it once was — or at least, has not targeted the same skills. Some of the IQ tests used have assessed people’s mental arithmetic, for instance — but as Ole Rogeberg at the University of Oslo points out to me, students are probably more used to using calculators.

“For now, it seems clear that our culture can shape our minds in mysterious ways.”

“Modern society is suffering from ‘temporal exhaustion’, the sociologist Elise Boulding once said. ‘If one is mentally out of breath all the time from dealing with the present, there is no energy left for imagining the future,’ she wrote.”

“While scientists continue to untangle the causes of those trends, it’s worth questioning what these changes in IQ actually mean for society at large. Has the IQ boost of the Flynn effect brought us the dividends we might have hoped? And if not, why not?”

To be continued on TTS CLUES #89.

Q: How intelligent do you think you are? Based on what?