Rationally Dumb?

Robert Frank wonders why there are so many jokes about dumb blondes and dumb athletes:

Despite the Dumb Jokes, Stereotypes May Reflect Some Smart Choices, by Robert H. Frank, Economic Scene, NY Times: A quick Web search identifies thousands of jokes about dumb blondes... There are almost as many jokes poking fun at the supposed mental deficiencies of athletes. ... [jokes in full version]

Since there is no persuasive evidence that blondes and athletes are less intelligent than others, such jokes pose a puzzle. Where do the underlying stereotypes come from? Definitive answers remain elusive, but an armchair economic analysis suggests some intriguing possibilities.

Let’s begin with the dumb blonde stereotype... [I]n Western countries, at least, blondness is viewed as a positive characteristic in women. The upshot, according to a recent paper by two sociologists, Satoshi Kanazawa of the London School of Economics and Jody L. Kovar of Indiana University of Pennsylvania, is that blondes should actually be more intelligent, on average, than others.

Their claim follows from four plausible propositions. ... (1) men generally place greater emphasis on looks; (2) women generally place greater emphasis on income and status. The point is not that men don’t care about a woman’s income or status, or that women don’t care about a man’s appearance. Rather, it is that the relative strengths of these concerns differ for men and women. The authors cite extensive evidence in support of both claims.

Their third and fourth propositions also appear to be solid: (3) more-intelligent men tend to achieve higher income and status; (4) both intelligence and physical attractiveness are traits with significant inheritable components. If the first three propositions are true, it follows logically that relatively attractive women will pair up disproportionately with relatively intelligent men. And if both beauty and intelligence are inheritable, then the offspring of such unions will tend to display above-average values of both traits.

In short, ... if gentlemen prefer blondes, fair-haired women should pair more often with intelligent, more successful men, and since hair color is at least weakly inheritable, a positive correlation should also emerge between blondness and intelligence.

What, then, accounts for the pervasiveness of dumb blonde jokes? The logic that governs decisions about investment in education and training suggests a possible answer. How intelligent you appear to others depends not only on your native mental abilities, but also on ... investment in education and training. ...

If blondes are perceived as more attractive, then being blond may create valuable opportunities that do not require onerous investments in education and training. The dumb blonde stereotype may thus stem from the fact that blondes rationally choose to invest less than others in education and other forms of human capital.

This interpretation is consistent with research documenting a positive link between earnings and physical attractiveness. In a 1993 paper, for example, two economists, Daniel Hamermesh of the University of Texas and Jeff E. Biddle of Michigan State University, reported that people described as good-looking earned more than 10 percent more than those described as plain. The authors also found that plain women were more likely to marry men with limited education.

The human capital story suggests a similar rationale for the dumb athlete stereotype. Contrary to popular impressions, intelligence and athletic ability may be slightly positively correlated in the population as a whole. ... But because gifted athletes enjoy many attractive social and employment opportunities that others do not, they may rationally choose to invest less, on average, in human capital.

The dumb athlete stereotype is further reinforced by the fact that varsity athletes at any given university are actually less intelligent than their classmates, since many were admitted primarily on the strength of their athletic skills, not because of their academic achievements. If each university admitted people whose last name begins with the letter “M” with SAT scores 400 points lower that those of other applicants, the false impression would quickly form that people with names like Martin and McDermott were mentally deficient. It is the same with athletes.

The bottom line is that popular perceptions about the intelligence of blondes and athletes may stem more from the academic choices made by members of these groups and from choices that others make about them than from any innate differences in mental ability.

Or perhaps jealous brunettes and nonathletes with time on their hands simply sit around making up jokes about their rivals.