> And some people have microencephaly. We're not talking about outliers. We're talking about the vast majority of people.
No, you specifically said "people without a disability". Unless you're going to expand the meaning of "disability", various permutations within the range of "normal" physical characteristics will impose different limits on athletic abilities, and analogously, the range of cognitive qualities (memory, focus, spatial reasoning, etc.) will do the same for cognitive tasks.
The fact that these qualities can be improved via training doesn't change the basic fact that those limits will be quite different for different people, even within the normal range. We can quibble all day about whether college algebra falls under that category, but this basic fact won't change.
> the range of cognitive qualities (memory, focus, spatial reasoning, etc.) will do the same for cognitive tasks.
And that range is smaller than the difference between your ability to perform cognitive tasks and the average high school dropout's ability to perform those tasks. Education makes a much larger difference.
I disagree. Education boosts IQ scores by 1-5 points [1], where 1 standard deviation from the mean IQ score is +/-15 points. The spread on cognitive abilities is clearly broader than education can cover.
Education has improved the average IQ of multiple East Asian countries by 15 points over two decades. That's an entire standard deviation improvement for the whole population. One-on-one tutoring has been shown to make a two standard deviation difference. That's the difference between median intelligence and genius. https://en.wikipedia.org/wiki/Bloom%27s_2_sigma_problem
Your study is about the effect of an extra year of badly done education on people who drop out of school, which is worth 1 IQ point. That same study shows that the effect of mediocre education on people who don't drop out of school is an increase of 5 IQ points.
No, you specifically said "people without a disability". Unless you're going to expand the meaning of "disability", various permutations within the range of "normal" physical characteristics will impose different limits on athletic abilities, and analogously, the range of cognitive qualities (memory, focus, spatial reasoning, etc.) will do the same for cognitive tasks.
The fact that these qualities can be improved via training doesn't change the basic fact that those limits will be quite different for different people, even within the normal range. We can quibble all day about whether college algebra falls under that category, but this basic fact won't change.