Are Smarter People Happier With Fewer Friends? What the Study Found

Originally published 2016-05-30.

Are smarter people happier with fewer friends? The short answer: one 2016 study found a pattern along those lines, but only for a small group of very high scorers, only as a statistical association, and only in a particular survey of young American adults. It does not show that intelligent people prefer solitude, and having a busy social life says nothing about your IQ.

The study became a viral headline, so it is worth looking at what the researchers actually did, what they found and what it cannot tell us.

The study behind the headline

The paper, titled Country roads, take me home… to my friends: How intelligence, population density, and friendship affect modern happiness, was written by evolutionary psychologists Norman P. Li of Singapore Management University and Satoshi Kanazawa of the London School of Economics. It appeared in the British Journal of Psychology in 2016 (volume 107, issue 4, pages 675 to 697).

The authors used data from the National Longitudinal Study of Adolescent to Adult Health, known as Add Health, a large US survey run from the University of North Carolina. Their analysis covered about 15,000 people aged 18 to 28, who answered questions about life satisfaction, how often they met friends and where they lived. Intelligence was measured with a vocabulary-based test given as part of the survey.

What the researchers found

Two findings will not surprise anyone. People living in more densely populated areas reported lower life satisfaction on average. And people who met their friends more often reported higher life satisfaction.

The twist concerned intelligence. Both associations were weaker among people with higher test scores. The negative link between density and satisfaction was, by the authors' estimate, more than twice as large for low scorers as for high scorers. And among the most intelligent respondents, the friendship link actually reversed: those who socialised with friends more often reported slightly lower satisfaction.

That last result is the one that became the headline. It is real within the data, but it describes a modest statistical pattern among a minority of respondents, not a rule about how clever people live.

The "savanna theory of happiness"

Li and Kanazawa interpreted their results through what they called the savanna theory of happiness. The idea builds on Kanazawa's earlier "savanna principle": human brains evolved for life in small hunter-gatherer bands, so situations that would have been good or bad for our ancestors may still shape how satisfied we feel today.

In ancestral groups of perhaps 150 people, regular contact with lifelong allies would have mattered for survival, while crowds of strangers were rare. That, the authors argue, is why density tends to lower satisfaction and friendship tends to raise it. They then proposed that more intelligent people, being better at handling evolutionarily novel problems, might be less bound by those ancestral preferences.

It is an interesting hypothesis, but it is an interpretation layered on top of survey correlations. The data do not test evolution directly, and other explanations fit the same numbers.

Why the result needs careful reading

Correlation, not cause

The survey shows that two things move together, not that one causes the other. Highly intelligent young adults who see friends less often may be busy with demanding studies or careers they find rewarding. Socialising might feel like time taken away from long-term goals, an explanation that came up in press coverage of the study.

A narrow sample

Everyone in the data set was a young American adult. Friendship patterns at 22 are not the same as at 45 or 70, and culture shapes how people socialise.

Small effects

Statistically significant does not mean large. A small dip in average satisfaction among a subgroup tells you very little about any individual.

Context about the authors

Kanazawa's wider work has been strongly criticised by other researchers, and in 2011 he faced condemnation over a blog post on race and attractiveness, after which the LSE barred him from non-peer-reviewed publishing for a year. That does not make this paper wrong, but it is a reason to read evolutionary explanations from this line of research with extra care.

Common myths the headline spread

• "Smart people don't need friends." The study did not find that. Average respondents, including many with high scores, were happier when they saw friends more.
• "Preferring solitude proves you're intelligent." The direction runs the other way at best, and only weakly. Introversion, social anxiety, busy schedules and personal taste all affect how much company someone wants.
• "Loners are happiest." Decades of research on well-being point to close relationships as one of the strongest predictors of happiness for most people.
• "The class genius is antisocial." Stereotypes about bright people being arrogant or awkward are not what the paper studied, and the data offer no support for them.

What to take from it

The most useful takeaway is personal rather than statistical. People differ in how much social contact recharges them. Some feel best after a full weekend with friends; others prefer one long conversation a week and plenty of quiet. Both are healthy, and preferences shift with age, workload and life stage.

Instead of counting friends as a score, ask which kind of contact leaves you feeling connected and which leaves you drained. If you have drifted into isolation and feel low or lonely, that is worth taking seriously; talk to someone you trust or to a doctor. But if you are simply happy with a small circle and time to think, you do not need a scientific label to justify it.

If you want to dig further, you may also enjoy our look at solitude, socialising and intelligence, which covers the same study from a different angle.

Sources: Li & Kanazawa (2016), British Journal of Psychology 107(4), via SMU repository, Wikipedia: Satoshi Kanazawa, The Washington Post (original coverage)