It is often said that the eyes are the mirror of the soul, and there is something true about this. It has long been known that pupils not only dilate and contract in response to light, but also in response to mental processes that take place in our brains.
For example, when we see something or someone that attracts us, they expand more so as not to lose the detail of what is in front of us. Likewise, in the simple memorization tasks, we have seen that the pupil expands as the elements are kept in memory and contracts each time one remembers something previously memorized.
Thus, our gaze expresses more of our inner world than one might expect. However, recent research takes this idea further, providing new evidence on the relationship between student behavior and our psychological facet: people with taller pupils tend to be smarter, statistically.
The connection between students and fluid intelligence
The results of this research, published in the journal Cognitive Psychology by a team of American psychologists, show that pupil diameter correlates with higher intelligence scores. In other words, groups of people with taller pupils are more likely to be smarter than others, although this rule should not be observed in all individuals.
To conduct this research, a group of 331 volunteers was used and the height of the students in which they adopted their “default” height was measured to ensure that the light levels did not affect the results. In addition, psychologists have taken into account variables such as age, sex or the consumption of certain substances such as nicotine. Once the influence of these variables was subtracted from the equation, the correlation between pupil size and intelligence emerged.
However, the measure of intelligence, the relationship with the diameter of the pupils was recorded by this group of psychologists was not a kind of intelligence.
Specifically, it was fluid intelligence, one of the most important components of IQ. fundamentally fluid intelligence refers to the mental agility with which we find solutions to unforeseen and new problems. It is therefore a type of intelligence that does not depend on our cultural level or on the knowledge acquired over the years.
How is this explained?
What causes this relationship between pupil size and higher scores in fluid intelligence is, for now, a mystery. Of course, this could be a spurious correlation, Either being the result of a curious coincidence or reflecting that there is a variable between these two that causes them both at the same time. For example, people with taller-than-normal pupils may come from a lineage of ancestors with neuroanatomical characteristics that make them smarter.
Another succinct explanation is offered by Jason S. Tsukahara, one of the researchers responsible for the study. The answer could be in a network of neurons sensitive to a substance called norepinephrine that are located in a part of the brain known as the locus coeruleus, located in the brainstem. He notes that other research has shown a relationship between the activity level of this group of nerve cells and pupil size. At the same time, norepinephrine makes neurons more likely to communicate with each other, creating new neural pathways that make it easier to find possible solutions and consider more options.
To clarify this, it will be necessary to repeat this research in different contexts and see if the correlation is present in each of them. This way, from there it will be possible to start developing a theory that explains the phenomenon.