Pupil size linked to IQ

Scientists have published research supporting the idea that a larger baseline pupil size is linked to higher cognitive ability.

The study, which was published in Cognition, highlighted that controversy has surrounded whether pupil size is linked to intelligence.

Research published in Cognitive Psychology in 2016 confirmed that a larger pupil size was linked to higher cognitive ability.

This difference was observable to the unaided eye comparing the pupils of individuals with high and low cognitive ability.

“These findings provide convincing evidence that the size of the pupil is a reliable and valid indicator of one’s cognitive ability and intelligence. We believe that this finding is important for what it may reveal about the underlying neural mechanisms of fluid intelligence,” the authors highlighted.

However, other scientists struggled to replicate these findings following the initial results.

The latest study from Georgia Institute of Technology researchers describes how a connection between pupil size and intelligence does exist but experiments need to be carried out under appropriate lighting conditions.

“We found that fluid intelligence, working memory capacity, and attention control did correlate with baseline pupil size except in the brightest lighting conditions,” the authors noted.