Well I happen to have a phd in that broader domain. It's not censorship, as you imply, but IQ is just way fuzzier a concept than people outside of this area of research think. The popular view is IQ is an objective thing, exactly measurable and so on (the metaphor of brains being computers, essentially). In reality you can put a 14 year old from a bad environment into an optimal environment and their IQ increases by up to 20 points over a view years.