A whole lot of people don’t seem to grasp what IQ is about. And I don’t even mean that defining or measuring intelligence is a bitch, but that the concept of IQ is often misunderstood. It’s not an absolute measure in the way that height or weight (or rather mass, if we’re being picky – and we are) are, but relative. It’s called ”intelligence quotient” for a reason. Failing to understand this basic premise results in sentences like the ones found in an article on gene manipulation on the Guardian Weekend (3.5.2003).

An ex-editor on Science is quoted in the article as saying If a child destined to have a permanently low IQ could be cured by replacing a gene, would anyone really argue with that? It is a short step from that decision to improving a normal IQ. Errors of this ilk are quite common but it gets worse.

A passage such as Of course, the problem is that if everyone’s adding 30 IQ points, then having an IQ of 150 won’t get you any closer to an elite university than you were at the outset shows exactly what the confusion is about. For IQ is defined in such a way that the median of all people will have an IQ of 100, meaning that if ”everyone adds 30 IQ points”, the resulting median still won’t be 130 but 100 and therefore talk of IQ points is quite useless, even misleading.

There is a possibility that this could be understood to be analogous to percentage points, but this theory can be easily debunked. Note how the author writes about adding 30 IQ points and thus resulting in an IQ of 150, not 150 IQ points. It’s the same as saying ”by adding 20 percentage points, the result is 150 percentages”, which is utter nonsense.

I’m not worried about possible mistakes I’ve made with statistical terms and concepts here, for I know I have an avid reader who’ll surely point out my possible shortcomings in no time.