*facepalm*

Just got linked to this article over at some blog. The article is essentially about g, the neurophysical substrate of intelligence, and its correlations with other beneficial qualities or events (like income, beauty and height). While I appriciate the idea of g, there's a bit of a mantra I have that I feel is appropriate in this situation.

Correlation is not causation!

Rinse and repeat. Y'see, while it's quite true there is a positive correlation between looks, height and intelligence, there's two itty bitty factors that are getting neglected here- there's also a correlation between those factors and nutrition and hygiene, and between good nutrition and good education.

I'd like to think that the conclusion is a bit obvious, but I'll say it anyway. Just because you're tall doesn't mean you're smart; counter-intuitively, the more global your sample becomes, the more biased it will be in this situation, since first world citizens will on average be taller and smarter than third world citizens, even if the tallest of the first worlders are not also the smartest.

Furthermore, the measurement of correlation is not expressed for the vaunted intelligence tests; I'm explicitly not disagreeing with the concept of g, but statistics are hard to get right. If the test is measuring aggregate rather than individual correlation, there's a huge problem right there. If people who do very well on one section of the test do very well on slightly over half the test and moderately well on the rest, and there's at least a little bit of distribution on which sections individuals score well on, the aggregate result will report that anyone who does well in one section will do well in all sections.

Both in addition and important on it's own, since we can assume that the areas being measured on the intelligence tests do overlap at least a little, it would be highly unlikely for someone to do well in one section of the test and not do well in 'adjoining' segments. This doesn't necessarily mean that they're not something of a savant; rather, it means that they've learned coping strategies which allow them to apply their strengths to related areas (for instance, someone with a heavily visual aptitude might be good at string repetition by processing the data as a visual sequence- a series of individually meaningless squiggles on the page or screen- whereas someone with a heavily verbal aptitude might be good in the same area because they've learned to process the data as a semantic sequence). After all, one confronts a problem with one's greatest available strength, not one's mediocrity or weakness.