News, Culture & Society

It’s in your eyes! People with large pupils are more INTELLIGENT, study finds 

Have you got a high EYE Q? People with large pupils are more intelligent, study finds 

  • Researchers tracked pupil size in volunteers taking a range of intelligence tests
  • These covered areas like intelligence, memory retention and the ability to focus 
  • They created a baseline measurement while volunteers looked at a blank screen
  • They found that those with larger baseline pupil sizes were more intelligent
  • This could be due to more activity in regions of the brain linked to intelligence 

People who have larger pupils in their eyes are more intelligent than those with smaller pupils, according to a new study. 

Volunteers sat reasoning, attention and memory tests so the Georgia Institute of Technology team could investigate the link between pupil size and intelligence. 

They found that as well as being linked to arousal and exhaustion, pupil dilation can be used to understand the individual differences in intelligence, discovering that the larger the pupils, the higher the intelligence. 

Differences in the baseline pupil size between those scoring highest and those scoring lowest on intelligence tests could be seen with the unaided eye. 

The team say this could be due to people with larger pupils having better results regulation of brain activity in a region linked to intelligence and memory. 

People who have larger pupils in their eyes are more intelligence than those with smaller pupils, according to a new study. Stock image

HOW DOES THE PUPIL WORK? 

The pupil is the opening in the centre of the iris (the structure that gives our eyes their colour). 

The function of the pupil is to allow light to enter the eye where it is then focused on the retina.   

The black colour of the pupil is because light that passes through it and is then absorbed by the retina – meaning no light is reflected.   

The size of the pupil and how much light enters it is controlled by muscles in the iris.

One muscle constricts the pupil opening and another iris muscle dilates the pupil.  

In low-light conditions, the pupil dilates so more light can reach the retina to improve night vision. 

In bright conditions, the pupil constricts to limit how much light enters the eye.

Researchers had 500 people aged 18 to 35 from Atlanta take part in a range of tests while having their pupil size monitored by an eye tracking device. 

This device captures the reflection of light off the pupil and cornea through a high powered camera. They were measured at rest while the volunteer stared as a blank screen for four minutes to create a baseline. 

This allowed them to create an average pupil size for each of the volunteers that would be used to track changes through different types of tests and activities.

Average human pupils, the black circular aperture at the centre of the eye, can range from 2 to 8mm and are surrounded by the iris that controls pupil size.

Once they’d created a baseline for every volunteer, they had them complete a series of tests that measured a range of areas of intelligence. 

This included the capacity to reason through problems, the ability to remember information over time and the ability to stay focused even when distracted. 

They found that those who had a larger ‘baseline pupil size’ performed better in the attention, memory and reasoning tests. 

This suggests a strong link between the brain and the eye that the researchers hope to study in more detail in the future. 

Pupil size was negatively linked to age, finding that older volunteers tended to have smaller and more constricted pupils. 

However, if they removed age as a factor, creating a standardised figure, the relationship between intelligence and pupil size was still there – regardless of age. 

Finding out exactly why pupil size is linked to intelligence required a more detailed study of the brain, to look for which regions are being activated.

They found pupil size is linked to a region known as the locus coeruleus in the upper brain stem that stretches out into the rest of the brain through neural connections. 

Volunteers sat reasoning, attention and memory tests so the Georgia Institute of Technology team could investigate the link between pupil size and intelligence. Stock image

Volunteers sat reasoning, attention and memory tests so the Georgia Institute of Technology team could investigate the link between pupil size and intelligence. Stock image

It releases a chemical that functions as a hormone int he brain and body and a neurotransmitter to regular processes like perception, attention and memory. 

This region also has a wider role in helping distant regions of the brain work together to complete complicated tasks.

The leading theory is that people with larger pupils have better regulation from this brain region, benefiting cognitive performance and the brains ability to function.

The findings have been published in the journal Cognition. 

‘INTELLIGENCE QUOTIENT’ (IQ) IS A MEASURE OF MENTAL ABILITY

IQ stands for Intelligence Quotient and it is used to measure mental ability.

The abbreviation ‘IQ’ was first coined by psychologist William Stern to describe the German term Intelligenzquotient.

Historically, IQ is a score achieved by dividing a person’s mental age, obtained with an intelligence test, by their age.

The resulting fraction is then multiplied by 100 to obtain an IQ score.

An IQ of 100 has long been considered the median score.

Because of the way the test results are scaled, a person with an IQ of 60 is not half as intelligent as someone with an IQ of 120.

The arrangement of IQ scores also means that results are ‘normally distributed’, meaning just as many people score either side of the average. 

For example, the same amount of people score 70 as people who score 130.

Although the accuracy of intelligence tests is somewhat disputed, they are still widely used.

For Mensa, the acceptance score requires members to be within the top two per cent of the general population.

Depending on the IQ test, this can require a score of at least 130.

Famous people’s IQ scores: 

  • Albert Einstein and Stephen Hawking – 160
  • Donald Trump – 156 
  • Emma Watson – 138  
  • Arnold Schwarzenegger – 135 
  • Nicole Kidman – 132



Read more at DailyMail.co.uk