The development of g rests on that assumption, but the measured correlations vary, and the correlations are lower for music & painting than between, e.g., STEM subjects.
Also interesting - the cross-subject correlations g measures actually decrease as intelligence increases. The smarter someone is (as measured by psychometric tests), the more likely they are to be “smart” in a single subject and not all subjects. This is an interesting self-contradiction in the whole theory.
> It makes perfect sense to me that socio-economics would correlate.
Yeah, I totally agree. But, it’s very important to know that the people like Spearman and others who developed IQ and g and other concepts of intelligence in the 1920s were specifically looking for the innate biological component of intelligence that explains “gifted” ability in the absence of nurture and environmental factors. That’s where this use of “gifted” came from - it’s pre-supposing that intelligence was not heavily influenced by the wealth of your parents, and they didn’t know how important nutrition and pollution were at the time. This is why I think using “gifted” is problematic. From that paper I linked to: “Reframing ‘gifts’ as ‘talents’ underscores both the domain-specific nature of these abilities and that their extent should be viewed as dynamic rather than static or preordained.”
One question that occurs to me - who are these gifts bestowed by? There are two obvious answers: nature and God. I think nature is historically what is meant by ‘gifted’ in the context of education, but I’ll speculate there’s at least a little bit of historical religious influence on the choice of that word. Given that we know that SES, nutrition, environment, education, parenting and many other factors have real measurable influences on both intelligence and outcomes for people, the nature & God explanations are somewhat lacking, right?