So please stop offering yourself as a counter-example of the trend (also, the key is to look within families, because the signal here is going to be swamped by other factors when you compare across populations). Height is a highly heritable trait where most of the variation within the population is due to variation as numerous genes.Third, a friend has sent me another paper which does confirm that even within sibling cohorts there does seem to be a correlation between height and I. The problem is that it is a very small one, so you need large data sets with a lot of power to see it. In other words, there isn’t a “tall” or “short” gene, but thousands and thousands of variants which shape the variation of the trait across the population.
Geoffrey Miller’s The Mating Mind: How Sexual Choice Shaped the Evolution of Human Nature, was predicated on this logic.Both traits were highly heritable, although there was greater evidence for non-additive genetic effects in males.After accounting for assortative mating, the correlation between height and IQ was found to be almost entirely genetic in nature.In general estimates for the heritability of intelligence tend to be somewhat lower, on the order of ~50% rather than 80-90%.It is due to the highly polygenic nature that both of these traits have been posited as candidates for a “good genes” model of sexual selection.This is what you have to do in discussions, but I’m not sure it really adds any value.