> alternate hypothesis that mutability of IQ is neutral with respect to evolution but evolving brain structures whose performance in certain tasks can be radica

> alternate hypothesis that mutability of IQ is neutral with respect to evolution but evolving brain structures whose performance in certain tasks can be radically improved in adulthood is difficult, period. Merely 'difficult' is not much of a counter-argument - almost every component of a human being is at least 'difficult' to design. There doesn't seem to be reason to believe creating higher intelligence is especially more costly, in comparison to the already achieved intelligence.