Where do smart people come from?

Question to the brain

Answer from Dr. Ulrike Basten and Prof. Dr. Christian Fiebach, Department of Neurocognitive Psychology at the Institute for Psychology at Goethe University Frankfurt am Main: Everyone knows this: some children learn faster than others and do better in all school subjects. It is similar later on at work: some colleagues understand problems particularly quickly and suggest better solutions. The fact that some people cope better with cognitive challenges than others can in large part be explained by differences in general intelligence. A high level of intelligence favors success in school and work, health and even a long life. But why do we differ in our intelligence?

There is no single region in the human brain that is responsible for intelligent performance. Rather, it is a network of certain regions of the cerebral cortex (frontal and parietal) as well as some subcortical regions that is important for intelligence.

A common belief is that the brains of smarter people work more efficiently. This means that more intelligent people achieve a certain level of performance with less neuronal effort when faced with cognitive challenges. Studies that have examined the relationship between intelligence and brain activity with electroencephalography (EEG) or functional magnetic resonance imaging (fMRI) do not consistently support this assumption. We assume that more intelligent people can only do easy to moderately difficult tasks with less brain activity. When it comes to difficult tasks, on the other hand, the brains of cognitively capable people run at full speed, while less intelligent people show less activation - possibly because they give up earlier on difficult tasks.

According to recent studies, differences in intelligence could be explained by a different network organization of the brain. This organization can be seen, for example, as a functional coupling of different brain regions under resting conditions. Here, too, it seems as if more intelligent brains are not organized more efficiently overall. For example, they do not generally have closer connections. But individual regions are characterized by a special network of intelligent people. We recently investigated the connections between different sub-networks (or 'modules') of the brain for the first time and discovered something interesting: Certain regions of the brain were more involved in the exchange of information between modules in more intelligent people. We believe that the network characteristics of smarter people make it easier for them to focus. Irrelevant, possibly annoying stimuli can be better masked out. This could be a general benefit for higher cognitive performance.

The causes of the connections between brain characteristics and intelligence are not yet sufficiently understood. It is possible that some people, because of their biological predispositions, develop brain networks that make intelligent performance more likely. The more frequent use of the brain for more intelligent performance could just as well have a positive effect on the formation of the networks in the brain. With everything we know about the influence of the plant and the environment on intelligence, an interplay between the two processes appears most likely. Finally, it must also be said that you cannot simply divide people into “stupid” and “intelligent” people. We are all on a broad spectrum of cognitive performance levels, and people who appear "stupid" to others may have talents in areas that are not covered by standardized intelligence tests.

Recorded by Andreas Grasskamp