A Surprising Sign Of A High IQ Brain (M)

High IQ brains have greater functional connectivity and higher synchronisation, but this has an unexpected real-world effect.

High IQ brains have greater functional connectivity and higher synchronisation, but this has an unexpected real-world effect.

Intelligent people take longer to solve difficult problems than those with lower IQs, a study finds.

The reason seems to be that people with higher IQs avoid jumping to conclusions, which means they are more likely to end up with the correct answer.

On simpler problems, though, people with high IQs do indeed answer more quickly.

Greater functional connectivity

The conclusions come from a study of 650 people who were given a series of logical problems to solve, which became steadily harder.

From a combination of brain scans and simulations of brain activity, the researchers found that the brains of smarter people took longer to solve difficult problems.

High IQ brains have greater functional connectivity and higher synchronisation.

It is these properties that allow the more intelligent brain to ‘hold out’ while complex information is being processed.

Dr Michael Schirner, the study’s first author, said:

“Synchronization, i.e., the formation of functional networks in the brain, alters the properties of working memory and thus the ability to ‘endure’ prolonged periods without a decision.

In more challenging tasks, you have to store previous progress in working memory while you explore other solution paths and then integrate these into each other.

This gathering of evidence for a particular solution may sometimes takes longer, but it also leads to better results.

We were able to use the model to show how excitation-inhibition balance at the global level of the whole brain network affects decision-making and working memory at the more granular level of individual neural groups.”

Brain simulations

To reach their conclusions, the researchers used simulations of brain activity, personalised for each of the 650 people in the study.

Professor Petra Ritter, study co-author, explained:

“We can reproduce the activity of individual brains very efficiently.

We found out in the process that these in silico brains behave differently from one another—and in the same way as their biological counterparts. Our virtual avatars match the intellectual performance and reaction times of their biological analogues.”

The simulations revealed that the brains of people with lower IQs cannot wait until all the various areas of the brain have finished their processing steps before ‘jumping to conclusions’.

In contrast, greater synchrony in high IQ brains allowed time for all the brain regions to complete their processing and deliver up an answer that was more likely to be correct.


The study was published in the journal Nature Communications (Shirner et al., 2023).

Get FREE email updates to PsyBlog

Hello, and welcome to PsyBlog. Thanks for dropping by.

This site is all about scientific research into how the mind works.

It’s mostly written by psychologist and author, Dr Jeremy Dean.

I try to dig up fascinating studies that tell us something about what it means to be human.

Get FREE email updates to PsyBlog. Join the mailing list.

Author: Jeremy Dean

Psychologist, Jeremy Dean, PhD is the founder and author of PsyBlog. He holds a doctorate in psychology from University College London and two other advanced degrees in psychology. He has been writing about scientific research on PsyBlog since 2004. He is also the author of the book "Making Habits, Breaking Habits" (Da Capo, 2013) and several ebooks.