Researchers have tested this many times, in different places, over many years, and they keep finding the same result. This one is safe to trust.
A sociologist spent over two years embedded inside elite professional firms, banks, law firms, consultancies, watching how they actually chose new hires. She sat in on interviews, read evaluations, listened to how recruiters described the candidates they wanted. One phrase came up constantly: culture fit. On paper it sounds reasonable, hiring people who will work well with the team. But when she looked at what culture fit meant in practice, it turned out to mean shared leisure activities and background. Interviewers gravitated to candidates who played the same sports, enjoyed the same kinds of travel, came from the same sort of upbringing, people they would enjoy being stuck in an airport with. In other words, culture fit largely meant hiring people from the same social and economic class as the interviewer, dressed up as a judgment about values.
Culture fit, the criterion that feels most like protecting your team, is often just comfort in disguise, and comfort tracks background more than ability. When you hire the person who feels like one of us, you are frequently hiring the person who reminds you of yourself, which narrows your team and screens out difference without you noticing. Real fit is about shared standards and how someone works, not shared hobbies or upbringing. Before you reject someone as not a culture fit, ask whether you mean they will not do good work here, or simply that they are not familiar, because those are very different things.
Source: Rivera, 2012, American Sociological Review.
Lauren Rivera, 2015
Rivera's full study, on how elite firms mistake social similarity for merit.
Draw your own card. It does not take long, and it rewards taking your time.