About Rationally Speaking

Rationally Speaking is a blog maintained by Prof. Massimo Pigliucci, a philosopher at the City University of New York. The blog reflects the Enlightenment figure Marquis de Condorcet's idea of what a public intellectual (yes, we know, that's such a bad word) ought to be: someone who devotes himself to "the tracking down of prejudices in the hiding places where priests, the schools, the government, and all long-established institutions had gathered and protected them." You're welcome. Please notice that the contents of this blog can be reprinted under the standard Creative Commons license.

Thursday, February 02, 2006

A good sense of humor will get you a date...

A recent article by Eric Bressler and Sigal Balshine published in Evolution and Human Behavior (vol. 27, pp. 29-39, 2006) found that a sense of humor increases your chances of going on a date, if you are a man. The authors tested a couple of hundreds psychology students at McMaster University (ok, not exactly a random sample of the population) for their preferences concerning people who expressed a sense of humor or produced rather humor-neutral statements in an allegedly autobiographical (but in fact prepared by the investigators) statement.

Bressler and Balshine found that women were paying attention to the perceived sense of humor of potential male partners, preferring those with humorous autobiographical statements. Men, on the other hand, did not express a preference for witty women, thereby confirming yet another stereotype about gender differences. Interestingly, however, humor did not have what psychologists call a “halo effect,” like, for example, physical attractiveness. In the latter case, people who are found to be more attractive are also rated higher on character and intelligence scales, even when no information has been provided to participants about either aspect. Instead, humorous males in the Bressler and Balshine study were judged to be less honest and less intelligent, tough they were also considered to be more socially adept. Hey, whatever happened to the idea that women chose mates based on trustworthiness and intellectual prowess? I don't mind been outclassed by Groucho Marx or Jon Stewart, but not the Three Stooges!

So far so good, as far as this type of study goes. The problem with Bressler and Balshine's paper is that it actually set out to test a hypothesis about the evolution of humor in humans. The hypothesis was proposed by evolutionary psychologist G. Miller, who suggested that a sense of humor has been selected because it is an indicator of good genes, sort of like the peacock's tail. Moreover, Miller claimed that men and women should both prefer funny individuals of opposite sex, since the long, monogamous relationships humans typically engage in make for symmetrical sexual selection.

To begin with, it isn't clear on what grounds one would think that humor is correlated with genes that confer higher reproductive fitness; for that matter, the very claim that there are genes affecting a complex behavioral and culturally-influenced trait like humor is dubious (it is possible, but there is no evidence whatsoever to back it up). Moreover, Bressler and Balshine's results actually contradict Miller's hypothesis on two counts. First, because they found gender-related differences in the evaluation of humor as a sexual attractor – contrary to Miller's prediction; second, because there was a negative relation between humor and trustworthiness or intelligence – the latter being traits usually thought to be under sexual selection in primates. So much for sense of humor = good genes theory.

Ah, but there lies the beauty of a quasi-scientific discipline such as evolutionary psychology: it takes just a bit of imagination to concoct an alternative explanation that rescues the original hypothesis. Bressler and Balshine do just that, and I'll leave to the curious reader to go through their paper for some additional amusement. The point is that this sort of post hoc rescue is precisely what makes evolutionary psychology a good, possibly even largely correct, form of narrative about human cognitive evolution. But it ain't no science.


  1. I disagree on both counts.

    Bressler & Balshine (B&B) provided an a priori prediction about sexual dimorphism in the attractiveness of humor that diverged from Miller's theory, and provided references supporting their prediction. They then verified their prediction. What's wrong with that?

    Furthermore, results often conflict with theory, particularly when the theory is new. B&B offered two explanations for why their results concerning the intelligence of humorous individuals conflicted with Miller's prediction: A) the theory is wrong, or B) the study didn't provide a critical test of the theory. These are the standard explanations, aren't they? Granted, they spent more time describing the latter possibility, but in so doing offered testable explanations for their results (e.g., if more "intelligent" forms of humor are used in future studies, that negative relationship between humor and intelligence should disappear). The possibility that Miller is wrong seems to require little additional elaboration.

    I don't understand how either of these makes evolutionary psychology a pseudo-science. Do you know of a scientific discipline that doesn't progress through theory, prediction, test, and comparison? Or one in which the theories never require revision? All sciences have uncertainty, and this is particularly true in a new topic of investigation. Seems to me that the appropriate response to this uncertainty is to discuss what the data show, and what they merely suggest (as B&B did). The inappropriate response is to throw everything away because it wasn't perfect from the beginning.

  2. Anonymous,

    of course you don't throw everything away because it isn't perfect. My point is that evo-psych is an extremely weak science because its basic assumption is that current human behavior evolved under Pleistocene conditions.

    While this is reasonable, we don't have access to fitness measures, or behavior patterns, from the Pleistocene. Any test based on current conditions is irrelevant, because the idea is that modern cultural environments are evolutionarily novel.

    That is what distinguishes psychology from evolutionary psychology, but it also constitutes the major disadvantage, in this case, of the evolutionary approach.

    Finally, we can't use the comparative approach, because there are very few species of closely related primates, they have been separated form us for millions of years, and they behave in completely different ways (just compare the chimpanzees with the bonobos: they are equally distant from us phylogenetically, but have evolved entirely different patterns of social behavior).

  3. The fact that the modern environment may be different from the ancestral environment is hardly specific to Homo sapiens. It's a problem in the analysis of ultimate function of all presumed adaptations in all species. Yes, the modern environment is likely more different than the EEA for humans than many nonhuman species, but that's a difference of degree, not kind. It seems that if that's the reason you think of evolutionary psych as a weak science, then you should also think of evolutionary biology (and a good portion of physics, for that matter) as weak, since the presumed cause in all cases is temporally distal and cannot be replicated. I disagree, and think that even without the ability to evaluate past fitness consequences, we can still use approaches like reverse engineering to gather evidence.

    And while the comparative approach isn't available for phylogenetically rare behaviors (such as humor), it can be employed for behaviors that we share in common with other animals. Chimps and bonobos may show some difference in social behavior (although not "entirely different"), but they also show many of the same behaviors. One of the strengths of the comparative approach is that - through phylogenetic control - it can account for the problem of common ancestry when evaluating whether a given phenotype has arisen due to selection from a shared environmental feature. How are humans exempt from this logic?

  4. Is positive skepticism scientific?


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