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August 5, 2005
Dennis the Denver dentist and Laura the Louisiana lawyer
Susan referred me to an article by Brett Pelham, Matthew Mirenberg, and John Jones, called "Why Susie sells seashells by the seashore: implicit egotism and major life decisions." Here's the abstract of the paper:
Because most people possess positive associations about themselves, most people prefer things that are connected to the self (e.g., the letters in one’s name). The authors refer to such preferences as implicit egotism. Ten studies assessed the role of implicit egotism in 2 major life decisions: where people choose to live and what people choose to do for a living. Studies 1–5 showed that people are disproportionately likely to live in places whose names resemble their own first or last names (e.g., people named Louis are disproportionately likely to live in St. Louis). Study 6 extended this finding to birthday number preferences. People were disproportionately likely to live in cities whose names began with their birthday numbers (e.g., Two Harbors, MN). Studies 7–10 suggested that people disproportionately choose careers whose labels resemble their names (e.g., people named Dennis or Denise are overrepresented among dentists). Implicit egotism appears to influence major life decisions. This idea stands in sharp contrast to many models of rational choice and attests to the importance of understanding implicit beliefs.
First off, I'm impressed that they did 10 different studies. Psychologists really take their work seriously! Lots of interesting tidbits (see end of this entry for a few).
Some order-of-magnitude calculations
I'd like now to take the next step and estimate the prevalence of this ego-naming phenomenon. Here are the data for female and male dentists and lawyers (for each category, the count (with expected counts, based on independence of the 2-way table, in parentheses):
| Den names | La names | ||
| Female dentists | 30 (21.4) | 64 (72.6) | |
| Female lawyers | 434 (442.6) | 1512 (1503.4) |
| Den names | La names | ||
| Male dentists | 247 (229.7) | 515 (532.3) | |
| Male lawyers | 1565 (1582.3) | 3685 (3667.7) |
Of the 1576 men in the study with names beginning with "Den," an extra 17.3 (that's 247-229.7) became dentists. That would suggest that the name effect changed the career decisions of 17.3/1576=1.1% of these "Den" guys. But that's an overestimate, since the denominator should be much larger--it should be all the "Den" guys, not just the dentists and lawyers.
According to the article, 0.415% of Americans in 1990 were named Dennis. Multiplying by approx 150 million in the labor force yields 620,000 Dennises. Pelham et al. report, "Taken together, the names Jerry and Walter have an average frequency of 0.416%, compared with a frequency of 0.415% for the name Dennis. Thus, if people named Dennis are more likely than people named Jerry or Walter to work as dentists, this would suggest that people named Dennis do, in fact, gravitate toward dentistry. A nationwide search focusing on each of these specific first names revealed 482 dentists named Dennis, 257 dentists named Walter, and 270 dentists named Jerry." If we assume that 482-(257+270)/2=221 of these Dennises are "extra" dentists--choosing the profession just based on their name--that gives 221/620000= .035% of Dennises choosing their career using this rule.
How to estimate a total effect?
It's an interesting example of conditional probability. If we accept the basic results of the study--the authors are pretty thorough at handing potential objections--if you meet a dentist named Dennis, it's quite likely that he picked the profession because of his name. But, an extremely low proportion of Dennises pick a career based on the name.
But, then again, there are other D careers. Presumably there are first-letter effects which are weaker than first-3-letter effects, but are still there. So, Dennises could also become doctors, dogcatchers, etc. It would be interesting to set up a simple model and try to estimate the total effect.
OK, now some more cool results from the Pelham et al. paper:
. . . whether people named George or Geoffrey (the two most common American first names beginning with Geo) were disproportionately likely to be published in the geosciences. We did not include additional names in the list because there simply are no such usable names. We consulted 1990 census data to identify the four European American male first names that were most similar in overall frequency to these two target names (using an expanded version of the procedure described in the supplemental portion of Study 7). The control names for George were Daniel, Kenneth, Donald, and Mark. The control names for Geoffrey were Pete, Randolph, Jonathon, and Bennie. . . . On the basis of the observed frequencies for the eight control names, there should have been 65.5 geoscientists named George or Geoffrey in Study 8. The observed number was 93, or about 42% more than the expected value.
Hardware store owners were about 80% more likely to have names beginning with the letter H as compared with R. In contrast, roofers showed the reverse pattern. They were about 70% more likely to have names beginning with R as compared with H.
Expected values dictated that 308.8 of the 45,908 women sampled should have resided in cities named after Saints who happened to share their first names. The actual number of women who showed this name–city matching effect was 445, which is 44% greater than the chance value. On the basis of expected values, 3,476.0 out of 594,305 men should have lived in Saint cities bearing their first names. The actual number of men who did so was 3,956, which is 14% greater than the chance value.
Just to repeat: this is me quoting the Pelham et al. paper; it's not my own work.
P.S. See here for more on this matter (including a reference to the paper that shows that people are disproportionately likely to marry others whose surnames begin with the same letter as their own). And here is my calculation that estimates that approximately 1% of Americans' career choices are influenced by the sound of their first name.
Posted by Andrew at August 5, 2005 12:35 AM
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» Frequencies of first and last names: a good example to illustrate the assumption of statistical independence and its problems from Statistical Modeling, Causal Inference, and Social Science
Gueorgi pointed us to this website on name frequencies. Gueorgi writes, Given a first and last name, it estimates the number of people in the US with the same name. They take the data from the 1990 Census and make... [Read More]
Tracked on December 4, 2006 7:17 AM
Comments
I'm often asked at meetings if I'm a biologist or a statistician, and have always been a bit unsure about how to answer. But, now I finally know.
Bob the statistician
Posted by: Bob O'H at August 6, 2005 3:26 AM.
Just discovered this old item because I only recently discovered this blog. The finding in the study I liked best was the huge disproportion of Florences living in Florida. Egotism, as the authors imply? Or ethnicity? Apparently Pelham et. al. are not familiar with the old Carnak-style joke.
The answer is: Venice, Rome, and Florence.
The question: name two Italian cities and the president of Hadassah
Posted by: JL at November 10, 2006 9:58 AM.
Posted by: Andrew ![[TypeKey Profile Page]](http://www.stat.columbia.edu/~cook/movabletype/mlm/nav-commenters.gif)
at November 10, 2006 10:55 AM.