Sunday, January 03, 2010

How I Read This Kind of “News” Article by Anthony McCarthy

Among the ideas promoted in the “Ideas” section of the Boston Globe this week, is this little curiosity.

Do tattoos mean good genes? Tattoos and unusual piercings carry the stereotype of nonconformity. Just ask yourself: How often do you see them on business managers or government officials? However, a new study from anthropologists in Poland suggests that, for men, tattoos and piercings are actually signals of biological quality. The researchers compared the body symmetry - specifically, measurements of the right and left hands - of people with tattoos and piercings to a similar group of people without tattoos and piercings. Symmetry has been established in previous research as a good indicator of biological quality (i.e., “good genes”). Men with tattoos and piercings were significantly more symmetrical than men without tattoos and piercings. The authors theorize that, given the pain and risk of infection from getting tattoos and piercings, only stronger men will get them.

Koziel, S. et al., “Tattoo and Piercing as Signals of Biological Quality,” Evolution and Human Behavior (forthcoming).

For the love of Mike, non-pathological biometrics as an indication of “biological quality” in 2010, if the real news wasn’t bad enough. Sixty-five years after the fall of Naziism and Imperial Japan, this published as science.

As so often in the “Surprising insights from the social sciences” by Kevin Lewis the reported study is forthcoming, and no numbers are given and hardly any methodology so we skeptics of this kind of tripe can get a sense of the validity of the alleged study. So we can’t judge the “insight” on that basis. We could look up the basis of their assumption that “Symmetry has been established in previous research as a good indicator of biological quality (i.e., “good genes”).” I assume they mean the stuff that says that people express a preference for photographs or artificial images of people with marginally more symmetrical measurements. Which, as I recall, seems to assume that because of that these people would produce more offspring. If that’s the case the theory of the authors faces a major hurdle, I’ve seldom seen tattoos that are done in conformity with body symmetry. They tend to destroy any visual symmetry. And, while I can’t speak for anyone else, even the few attempts to symmetrically tattoo the face creep me out entirely.

And, I don’t know about the folks these people measured, but I’ve known plenty of men and, more recently, women with tattoos who, otherwise symmetrical or not, were anything but desirable spouses. Some of the men, in particular, I’ve observed who indulged the art are notably rotten parents. Rest assured, I’ve also known people with tattoos who were perfectly fine and attractive, the tattoo didn’t make the person, though when it gets out of hand it generally makes you wonder.

The lack of measurements of the variation in “symmetry” also is a problem to understanding this. I get the feeling we are not talking about huge numbers. What body parts were measured and what role could non-genetic factors, different occupations, habits, recreation, could account for the difference in the measurements? I can tell you from personal experience that something like not switching hands when sawing wood or playing the violin instead of the piano can lead to a noticeable difference in body symmetry. If those possibilities weren’t taken into sufficient account, the results could be entirely useless.

I don’t know if it’s of relevance to present day conditions or to the study population, but many of the men I know who have them, were tattooed while they were in the military, I’d assume for purposes that were anything but nonconformist and in a display of macho daring. I suspect that could skew the “fittness” differential in the study for quite non-genetic reasons.

But the real insight I had reading this had nothing to do with the farfetched study and its farther fetched conclusion, it was in the matter of our assumption that what might be considered a statistically significant indication in something such as a chemical or physical process, can reveal anything about something as variable as human preference, thought and the decision to act on those.

Is there any real reason to believe that the expressed preference for fleetingly viewed images has any real effect on something such as the decision to marry and have children with a specific individual? People in their social interactions aren’t anywhere near as reliably superficial as the “social sciences” would find convenient. I’m skeptical about the consistent meaning of statistical significance in something so complex and unknown as human volition. Especially in the very complex, very little known and enormously variable ‘behaviors’ that are the intended subjects of these folks. My suspicion is that the whole enterprise is based more on a desire to publish something, anything, than it is in the importance of either the topic of the conclusions reached. Just off hand, I’d really like to know how many recently published papers in these journals DON’T end up supporting the presently fashionable genetically deterministic orthodoxy that rules in the soc-sci world.

There is no reason I’m aware of to accept the notion that peoples’ behavior can be reliably understood on the basis of statistical analysis. To take that kind of analysis, mixed with previous assumptions and to start talking about something as real as physical genes, becomes indistinguishable from fundamentalist faith, religious or political.

So, do folks with tattoos have more children who live to reproduce than those without? Are they healthier by some objective measurement? If someone can cite reliable studies of sufficient size to show that the marginally more “symmetrical” have more reproductive success and rear their children to adulthood more successfully than the slightly “asymmetrical”, please, give us the citations. Just include the numbers so we can have some idea if it’s convincing.

But even more interesting, read the item just below this one which concludes:
The authors theorize that the sensation of hunger, as a survival cue, prompts men to seek hardier females, and prompts women to seek more protective men.

Does that mean the social convention of going to a restaurant on a date leads to less fitness in the general population? Horrors! Just think of the biological implications.