There are papers that support the ability to change IQ or “fluid intelligence.” I don’t know what depression is like, in the case of antanarchy’s comment, but you can clearly lower someone’s IQ with drugs–why not long term environmental changes? I don’t know to what extent. I think Marian Diamond used to get significant changes in rats by changing developmental conditions.
It’s also good not to go crazy about IQ. I don’t see how anyone could care or argue about a few points in either direction, especially once you’re ~3 SD’s above average. I remember there was a chess knight problem on one of the Hoeflin tests. Someone smart, but who has never played chess, could get the problem, but it’d take longer than for someone smart who does play. Does that mean chess increases IQ? …Probably better to just say experience affects IQ.
There is no “innate intelligence” or innate overall mental ability, which some people associate with IQ. I think IQ has lots of carryover, but it is technically testing ability only in certain problems.
James Flynn is an acquaintance of mine. You can look him up on Wikipedia if you like. He would disagree with you that IQ measures only test taking ability.
IQ also has .42 with brain size on MRI, and there is also a good correlation with reaction time tests. Yes, people with higher IQ’s have faster reaction times. There is also a correlation with a test on the ability of the brain to utilize glucose. People with higher IQ’s utilize glucose in the brain in a more efficient way.
Also the man in the US with one of the highest IQ’s ever recorded has a massive head. Only one in 3 million people has a head as big as his. He had to have a motorcycle helmet specially made for him.
