Children can be trained for IQ tests. Your original claim seems to be much stronger than that. It was my impression that you were asserting that children are tr

Children can be trained for IQ tests. Your original claim seems to be much stronger than that. It was my impression that you were asserting that children are trained for IQ tests accidentally, merely by living in an enriched home and school environment. There is no evidence for that and twin and adoption studies show evidence to the contrary: that adopted children and especially twins raised separately over/underperform their adoptive families and perform similarly to their biological relatives. The only thing we know that can overwhelm innate ability is crushing poverty and the malnutrition and other extreme stresses that come with it. Otherwise, the effect of home environment on IQ is minimal. It’s different, of course, with language acquisition. Kids learn more vocabulary the more you speak to them and read to them. Kids with wealthy upbringings can have much more opportunity to acquire language than otherwise. The extent to which that helps with abstract pattern recognition, mental rotation, etc is limited. And we have plenty of examples of kids with logical and spatial reasoning that far exceeds their language skills. It’s such a common phenomenon that we have a name for these kids: nerd.