The Most Obvious Sign Of Intelligence

Brain scans measured the total surface area of the cortex and its thickness.

Brain scans measured the total surface area of the cortex and its thickness.

Taller people are more intelligent, on average, new research finds.

The reason is that taller people have proportionally larger heads.

A larger head generally gives people higher cognitive ability.

Of course shorter people with smaller heads can also be highly intelligent, however they are slightly rarer.

Dr Eero Vuoksimaa, the study’s first author, said:

“Even though taller individuals have, on average, bigger brain compared to shorter people, the size of any given individual’s brain cannot be determined by their stature alone.

Further, cognitive ability is not simply determined by brain size.

The findings do, however, shed light on the biological mechanism underlying the association between height and cognition.”

The study used brain scans to measure both the total surface area of the cortex and its thickness.

Participants were 534 middle-aged men, around half of whom were identical and non-identical twins.

The results showed that taller people had greater surface area of their cortex, but not a thicker cortex.

Dr Vuoksimaa said:

“These observations are in line with recent MRI studies of cortical development suggesting that cortical surface area increases until approximately the age of 12, whereas thinning of cortex occurs across the childhood and adolescence.”

Genetics is the major factor in cortical size, cognition and health, although environmental factors play a part Dr Vuoksimaa said:

“For example, childhood malnutrition has an impact on both height and brain growth, and affects also cognitive development.”

The study was published in the journal Brain Structure and Function (Vuoksimaa et al., 2018).

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.

Get free email updates

Join the free PsyBlog mailing list. No spam, ever.