How Intelligence and Personality Shape Our Career Trajectories
A study reveals the occupations with the highest and lowest IQs and Big Five scores
How do our IQs and personality traits shape the jobs we choose - or the jobs that choose us? A fascinating 2023 study by Tobias Wolfram, published in the journal Intelligence, explores the connections between cognitive ability, personality, and occupational sorting. Whereas earlier research relied on small or unrepresentative samples, Wolfram’s work draws on data from a representative U.K. sample of more than 40,000 people. It confirms the long-standing hypothesis that intelligence plays a pivotal role in determining which careers people end up in, and the status and pay of those careers. And it extends the analysis to various non-cognitive factors, including the Big Five personality traits, delayed gratification, self-efficacy, risk-proneness, and mental health.
What Did the Study Find?
Wolfram’s paper is packed with interesting findings and insights. Nothing tells a story like a good graph, though - so to get the lowdown on the results, let’s look at five key graphs from his paper.
1. Intelligence is a Major Predictor of Occupation
The first graph shows the extent to which intelligence and various sociodemographic variables explain which occupations people end up in. As you can see, intelligence explains more than any other variable except sex, edging out education and significantly outperforming age. In last place is parental education - a finding that challenges the popular belief that family background plays an outsized role in shaping people’s career paths.
One crucial detail not captured in the graph, but reported in the paper, is that intelligence is a considerably stronger predictor of people’s careers than the Big Five personality traits or any other non-cognitive variable.
2. The Highest and Lowest Ranking Professions by IQ
The second graph shows the 15 occupations with the highest average IQ scores, and the 15 occupations with the lowest. As we might expect, cognitively demanding professions (such as physicist, lawyer, and financial manager) occupy the top spots, whereas manual and service-oriented roles cluster at the bottom.
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3. The Highest and Lowest Ranking Professions by Personality
Graph number three shows the occupations with the highest scores and lowest scores on the Big Five personality traits, delayed gratification, mental health, risk-taking, and self-efficacy. Again, the rankings make intuitive sense. For example, childminders score high in agreeableness, hairdressers score high in extraversion, and musicians score high in openness.
4. IQ and Personality Predict Job Status and Income
The fourth graph reveals how IQ and the non-cognitive variables correlate with occupational status and income. IQ is a strong predictor of both, with delayed gratification coming in a close second. Other significant predictors include conscientiousness, openness, risk tolerance, and self-efficacy. Meanwhile, agreeableness, extraversion, neuroticism, and mental health show weak or even slightly negative associations with job status and income.

5. The Higher a Field’s Average IQ, the Less Its IQ Variation
The fifth and final graph shows that professions with higher average IQs tend to have less variation in IQ among their employees. This is because high-IQ individuals can do low-IQ jobs, but low-IQ individuals can’t do high-IQ ones. As a result, high-IQ professions inevitably draw from a narrower band of the IQ spectrum.
And what goes for IQ goes as well for conscientiousness, delayed gratification, openness, mental health, risk-taking, and self-efficacy: Jobs with higher average scores on these traits show less variability. Interestingly, the opposite is true for extraversion and neuroticism: Jobs with higher average scores on these traits show more variability.
Why It Matters
Wolfram’s research sheds valuable light on the psychological variables determining which careers we end up in, and the prestige and pay of those careers. Intelligence is particularly important, but personality traits and other non-cognitive variables also play their part. Taken together, these factors not only help shape people’s career trajectories, but also the structure of the modern working world.
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If you want to dig deeper into the details, you can access the paper here. If you hit a paywall, you can request a free copy from the author here.
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Coming Soon to the Nature-Nurture-Nietzsche Newsletter…
Could Women Learn to Find Househusbands Sexy? Why Status Might Always Win Over Dishes
The Science of Controversial Science, Part I: How People React to Research on Sex Differences
The Twin Pillars of Success: Two Papers Explore the Links Between Intelligence and Personality… and Some Tips on Reading Research in Psychology
Think I found the comparatively low relevance of parental education the most surprising. Runs counter to the current commonly held / popular view.
Thanks!