It's not impossible that these tests measure something other than general intelligence, that just happens to correlate with social outcomes (like historical, relative familial wealth).
IIRC general intelligence also doesn't simply measure speed of cognition, but also ability to choose what to focus on ("intuition"), which these tests do not measure.
Adoptees have IQs in line with their biological parents, not their adoptive ones. It’s heritable like every other psychological variable I’m aware of.
Speed of cognition is absolutely correlated with IQ but the difference in speed doesn’t cause the differences in results. Both are downstream of being more intelligent.
> Speed of information processing and general intelligence
> One hundred university students were given five tests of speed-of-processing, measuring their speed of encoding, short-term memory scanning, long-term memory retrieval, efficiency of short-term memory storage and processing, and simple and choice reaction time or decision-making speed. They were also given the Wechsler Adult Intelligence Scale and the Raven Advanced Progression Matrices. A number of multiple regression analyses show that the cognitive processing measures are significantly related to IQ scores. Other analyses indicate that this relationship cannot be attributed to the common content shared by the reaction time and the intelligence tests, nor to the fact that parts of the WAIS are timed. It is concluded that the reaction time tests measure basic cognitive operations which are involved in many forms of intellectual behavior, and that individual differences in intelligence can be attributed, to a moderate extent, to variance in the speed or efficiency with which individuals can execute these operations
There is no evidence connecting IQ to hereditary traits. This has been demonstrably proven false multiple times. What you are arguing is eugenics and that is patently false.
> Substantial genetic influence on cognitive abilities in twins 80 or more years old.
> General and specific cognitive abilities were studied in intact Swedish same-sex twin pairs 80 or more years old for whom neither twin had major cognitive, sensory, or motor impairment. Resemblance for 110 identical twin pairs significantly exceeded resemblance for 130 fraternal same-sex twin pairs for all abilities. Maximum-likelihood model-fitting estimates of heritability were 62 percent for general cognitive ability, 55 percent for verbal ability, 32 percent for spatial ability, 62 percent for speed of processing, and 52 percent for …
This is great for Swedish people. The problem is that humanity consists largely of not-Swedish people. Same for most studies of this kind, which are largely concerned with populations that are already genetically closely related; it stands to reason that the differences between people who are closely related will be more attributable to their inborn differences, than the differences between people who are not closely related. They haven't been able to do an interracial, intercultural comparison on this because socioeconomic circumstances are so substantially different between groups (and have been so since the rise of modern empirical research) that it's impossible to set up a decent comparative study.
So if intelligence is inherited, then children of geniuses should be uber-geniuses. And if intelligence is a desired trait, then people can breed for that. And that's eugenics, so I believe you're agreeing with me.
Or intelligence is correlated with familial wealth because it is hereditary and smarter people tend to end up in more complex cognitively demanding professions which tend to pay more.
Maybe? The confounding factors are many. How to account for war (which often accrues wealth to the most brutal among the reasonably intelligent), disease (where selection is based on behavior, e.g., adherence to cultural norms, not necessarily intelligence), disparities in wealth across geography and culture (relative shifts in the normal distribution of IQ across demographics are reflected exactly in measures of wealth)? Let alone that procreation necessarily requires the joining of individuals who might have disparities in wealth, or intelligence, or both.
I tend to err on the side of caution with this one.
IIRC general intelligence also doesn't simply measure speed of cognition, but also ability to choose what to focus on ("intuition"), which these tests do not measure.