Pupil Size Is a Marker of Intelligence

There is a surprising correlation between baseline pupil size and several measures of cognitive ability

Credit: Erik Von Weber Getty Images

It has been said that “the eyes are the window to the soul,” but new research suggests that they may be a window to the brain as well.

Our pupils respond to more than just the light. They indicate arousal, interest or mental exhaustion. Pupil dilation is even used by the FBI to detect deception. Now work conducted in our laboratory at the Georgia Institute of Technology suggests that baseline pupil size is closely related to individual differences in intelligence. The larger the pupils, the higher the intelligence, as measured by tests of reasoning, attention and memory. In fact, across three studies, we found that the difference in baseline pupil size between people who scored the highest on the cognitive tests and those who scored the lowest was large enough to be detected by the unaided eye.

student in cognition and brain science at the Georgia Institute of Technology, where he does research in the Attention & Working Memory Lab.

Source