Is it possible to raise your IQ (best correlate for g I know of)? Does brain training help?
I have never taken a psychologist administered IQ test before, but I did take a reputable online IQ test and experienced a shift of 20+ IQ points over a two/three year period.
I didn't do the tests incessantly, did it once, then revisited the test a few years later, and I was testing 20+ points higher than my previous score.