By Alex Fradera

In theory, our personal traits and interests should affect the jobs we pursue and where we thrive the most. This assumption is baked into the Work Psychology theory of “person-environment fit” and it’s an idea that is foundational to services we depend on like vocational guidance and career planning. But one of its key implications has until now been untested: that people who share the same job role will also have similar job interests. Now a surprising new study in the Journal of Vocational Behavior suggests that for many jobs, this simply isn’t true.

The Michigan State University research team led by Christopher Nye used the Strong Interest Inventory (that measures interest in six areas: Realistic, Investigative, Artistic, Social, Enterprising and Conventional) to determine whether people in the same occupation were similar in terms of which was their top-ranked interest.

Among their sample of 67,000 people, across 211 jobs, those in the same occupational role did sometimes show a strong tendency to share the same primary interest – the strongest example being for fine artists, auto mechanics and carpenters, where in each case, 82 per cent of role holders shared the same focus – Artistic for the first and Realistic for the latter two.

But people in other occupations showed much less similarity in interests. For instance, in almost half of the occupations, only the thinnest of majorities tended to share the same interest, meaning that a lot of the time two people in the exact same job often had very different occupational interests.

Could the results be skewed by the sample being stacked with people trapped in jobs that they hate? This isn’t plausible, as the study only involved people who were reasonably satisfied in their role and had worked there at least three years.

It’s possible the variability was exaggerated by only focusing on the top interest. So in a second study using different occupational samples (58 datasets in total), the research team tried a more sophisticated statistical angle that looked for the degree of alignment between a person’s top three interests and the three interests conventionally considered to characterise the job. Nye’s team found that just over half the jobs showed more alignment than you would expect to see at random, but the remaining 45 per cent were the same or less. What this means is that a sizeable minority of occupations are filled by people who aren’t especially interested in the type of work their role is understood to require.

Defenders of person-environment fit could rustle up some retorts. You might find people with a poor fit in jobs with low barriers to entry, which are easy to fall into without any forethought. Perhaps if analysis were restricted to challenging vocations with higher barriers to entry, or people staying in jobs for a long time, there would be far more congruence between interests and job roles? In fact, the first study showed no effect of occupational tenure – people longer in jobs did not have a better fit than newer incumbents. And the second study showed that employees in several jobs that require extensive preparation or specialist education also had diverse interests, such as secondary school teacher and even clergy.

This suggests we should reconsider the assumption that people are primarily drawn to jobs because of the types of things they want to do. In some cases this is sure to be true, but exceptions abound. Some people chase a job not for what it involves but for the money, or security, or the company they get to keep. And people may find ways to shape jobs around their own interests – called job crafting – or be able to draw from it rewards that may not be obvious to everyone, such as the London Tube station assistant who wrote a book on how the experience delivered to his philosophical, Investigative interests.

This work may give some careers advisors pause for thought – occupational interests are often used as the easy shorthand to determine recommendations, but a multi-level approach considering personality and broader life goals is preferable. And for ourselves, we should allow our curiosity to be roused. When you’re next at work, why not ask your colleagues what led them to the work they are doing, and what they get from it. The answer is likely to surprise you.

—Do ornithologists flock together? Examining the homogeneity of interests in occupations

Alex Fradera (@alexfradera) is Staff Writer at BPS Research Digest