Teenagers who believe they are particularly intelligent tend to be more narcissistic and happier with life

Though it may vary based on context or mood, most of us have a fairly steady belief in how intelligent we think we are.

Whether that belief is in any way accurate or even helpful is a different question — one 2019 study found that people who were happier to admit they don't know something actually had better general knowledge, whilst a survey from the year before found that the majority of Americans believed they were smarter than average.

We're also susceptible to the same foibles when it comes to those close to us, tending to rate our romantic partners as more intelligent than they actually are. 

But how early do our ideas about our own intelligence start, and how do they relate to other facets of our personality? In new research published in Personality and Individual Differences, Marcin Zajenkowski looks at just that.

The way we perceive our intelligence seems to have an important effect on both academic achievement and how we feel about ourselves. Though studies have largely focused on adults, Zajenkowski argues that this is also likely to be the case amongst teenagers, too, where some evidence has already suggested that self-perceived ability in Maths and English is correlated with actual achievement.

First, Zajenkowski asked 428 teenagers aged between 15 and 17 to rate their own intelligence compared to other people on a scale from 1 (very low) to 25 (very high). Next, they completed a test of objective intelligence which measured abstract and non-verbal reasoning.

Participants also completed a measure of the Big Five personality traits, and the Narcissistic Personality Inventory was used to assess grandiose narcissism: participants rated themselves on 34 statements such as "I have a natural talent for influencing people" and "I will be a success". Finally, participants rated their life satisfaction, rating how much they agreed or disagreed with sentiments including "in most ways my life is close to my ideal".

Zajenkowski found that teenagers with higher levels of narcissism and those who scored higher on the "intellect" personality trait tended to make higher assessments of their own intelligence. These participants also showed greater levels of life satisfaction.

Gender also played a part, with male students scoring significantly higher than female students on self-assessed intelligence, as well as narcissism, extraversion and life satisfaction. But, importantly, there was no gender difference in objective intelligence.

This mirrors what had already been found in adult populations (one researcher dubbed it the "male hubris, female humility" effect). It's not clear when in development self-assessed intelligence starts to become associated with gender, though studies looking at only slightly younger children have found no gendered difference.

But unlike in studies on adults, there was no correlation between self-assessed intelligence and objective intelligence. Zajenkowski argues that this may be down to the way objective intelligence was measured: the test used in this study looked at abstract thinking, and  previous research has suggested that people may not see this kind of thinking as an aspect of intelligence until they're of university age. Teenagers, therefore, may not value it or even see it as a facet of intelligence.

It could therefore be useful to include a wider range of IQ tests in future work. Firstly, this could provide a more comprehensive picture of intellect with which to compare self-assessed intelligence; secondly, it may be a better fit when it comes to how teenagers perceive what intelligence actually means.

Effort must also be made by educators and families to ensure that girls are just as confident and sure in their abilities and intelligence as boys. Not only might this increase well-being, it could disrupt negative gender stereotypes as it does so.

Further reading

– How do teenagers perceive their intelligence? Narcissism, intellect, well-being and gender as correlates of self-assessed intelligence among adolescents

About the author

Emily Reynolds is a staff writer at BPS Research Digest