Somebody recently pointed out to me a striking fact: being named Dennis makes people more likely to become dentists. The idea is utterly splendid. It’s also untrue, and has been known to be untrue for five years. The fact that the claim is repeated by knowledgeable people tells us something important about the way that ideas spread.
Back in 1994, New Scientist magazine drew attention to the author of a book about the polar regions, Daniel Snowman. An avalanche of apt names followed: the incontinence experts JW Splatt and D Weedon; Manchester Ship Canal scholar Sue Grimditch; highly paid bankers Rich Ricci and Bob Diamond; prison reformer Frances Crook; and, of course, the former Lord Chief Justice, Lord Judge. The idea of nominative determinism — that your name determines your fate — spread because it was fun.
But then social psychologists started to take the idea seriously. The theory of “implicit egotism” is that people are unconsciously attracted by things that remind them of themselves — and, in particular, to echoes of their own names. Dennis would tend to pursue dentistry, while Laura would be tempted to become a lawyer. Georgina would move to Georgia, and Erica would be more likely to accept a proposal of marriage from Eric than from Bob.
The source of the Dennis/dentist claim is not some urban myth: it’s a peer-reviewed article published in 2002 in the Journal of Personality and Social Psychology. That article found that although Dennis, Walter and Jerry are equally popular names, there are almost twice as many people named “Dennis” working as dentists as there are people named Walter or Jerry. Other studies found that people were disproportionately likely to marry someone with a similar last name, and to move to areas resembling their name. These findings are not only recycled among casual consumers of pop psychology, they’re in leading psychology textbooks.
But, in 2011, the psychologist Uri Simonsohn published a review of the evidence for nominative determinism. Simonsohn, an important researcher in his own right, is increasingly carving out territory as a debunker of shaky ideas in psychology.
Simonsohn found that the Dennis/dentist connection is a statistical artefact — as can clearly be seen by the fact that Dennis is a more popular name than Walter, not only for dentists but for lawyers. This is because while Walter is just as common a name as Dennis, it is particularly common among elderly gentlemen who have passed retirement age. Dennis is not just more likely than Walter to be a dentist; he’s more likely than Walter to have any job at all.
Another curious finding is that George and Geoffrey seem oddly likely to do doctoral research in geosciences. Evidence for nominative determinism? No. These genteel Geo names are even more over-represented in other sciences.
What about marriage? Do people with the same or similar names tend to marry each other? Yes — but not necessarily because the name itself is attractive.
The first thing to understand is that if people married totally at random, we would expect only a few same-surname matches to occur. Because the baseline is low, a few extra matches are enough to provide (possibly spurious) evidence for the implicit egotism theory. What might explain those extra matches? Looking at data drawn from Texas, Simonsohn finds over 200 same-surname marriages based on just four names: Patel, Nguyen, Tran and Kim. These 200 marriages are easily enough to skew the data, and it’s clear enough that what is going on is simply marriage within immigrant communities.
Then there’s the tale of Candi Nehring, who married Stephen Nehring in 2001. The unconscious attraction of the Nehring name? Hardly. It seems that Candi and Stephen had been married before, divorced and remarried. Whatever the emotional dynamic might have been, I am confident that Candi Nehring didn’t marry her ex-husband because she really liked his surname. Other women marry their former brothers-in-law. And clerical errors can also create false cases of matched-surname marriages.
Enough. Reading Simonsohn’s paper, the big picture emerges long before he has finished his patient dissection of eight separate findings of nominative determinism, and shown that all eight of them appear to be correlations with a more straightforward explanation. The theory of implicit egotism is pleasing nonsense.
So why do people still tell me that Dennis is likely to become a dentist? I think the truth is that nominative determinism hits a mental sweet spot. We chuckle when we hear that a senior judge is called Igor Judge. We’re astonished and delighted to hear that the boffins have gone out and discovered that people really do seek out professions and spouses that echo their own names. It’s a finding that is simple to remember, faintly intuitive and yet surprising enough to talk about to other people. It spreads.
Old ideas die hard — especially when they are interesting and fun. I am told that we live in a post-factual age, and perhaps there are more important things to worry about than whether Dennis is likely to become a dentist. Still, even when the myth is delightful and the truth is dull, the truth still matters.
Written for and first published in the Financial Times.