This might be confusing the cart with the horse though, since this doesn't control for IQ. A person with a high IQ might be more attracted to math because of it's relative ease and also be able to pick up specific cognitive skills faster (i.e. being able to play snakebird well). In other words, correlation doesn't imply causation.

Transfer learning isn't what is controversial, it is far and/or general transfer to many different domains which is controversial. There is no verified method of raising general intelligence, for example.