We demonstrate a significant positive relationship between absolute latitude and human orbital volume, an index of eyeball size. Owing to tight scaling between visual system components, this will translate into enlarged visual cortices at higher latitudes.Bigger brains, and by usual (though not in this case) inference, higher intelligence ranks at least as high on the list of taboos as race does. Telling someone they are less intelligent is one of the worst things one can say about another. As a consequence, research into intelligence is under more scrutiny than most other disciplines, and freely voicing hypotheticals can get researchers fired.
In the world of bats, saying someone has substandard echolocation is not politically correct. Among snails, calling someone fast is frowned upon. Elephants are known to ostracize those claiming to have longer trunks that others. Because if a bat or snail or elephant is substandard in the prime measure of worth, then the fear is that they will be treated badly by those with better echolocation, speed, and trunks.
But luckily (eh?), the study does not suggest any difference in intelligence after all. Just that we Scandinavians have bigger brains because we need to be more sensitive to light, because there is less of it. Phew! Perhaps now we can even use this data to cancel out any differences in intelligence? After all, that there should be any systematic variation in intelligence among human populations is, unlike many other traits, just unthinkable!!!
Pearce, E., & Dunbar, R. (2011). Latitudinal variation in light levels drives human visual system size Biology Letters DOI: 10.1098/rsbl.2011.0570