> Since they don't know if these are MZ or DZ, usually the estimate is made they are about 50-50 (for same-sex, because 67% twins are DZs, but only 50% of those are same-sex)
In Europeans, hopefully? I understood that the rate of MZ twins was more or less constant cross-racially, but the rate of DZ twins is not.
"Mento" at the Marginal Revolution blog summarises Scott Alexander's post as:
"Scott Alexander thinks the “heritability gap” is real but mostly on the measurement side. He thinks classical twin/pedigree/adoption numbers (~0.5–0.7 for IQ) will hold but that somehow molecular biology tools and methods are today not yet able to evidence it, so it’s still an open question. More progress is needed."
You mentioned adjustments for Reliability, which I think means how close someone's score is when he takes a test over again the next day. When people talk about heritability estimates for IQ, is it standard to adjust for reliability? (it should be)
"For example, studies on the WAIS-R showed test-retest reliability coefficients of 0.86, 0.85, and 0.90 for Verbal, Performance, and Full-Scale IQs respectively, in a sample of older individuals. "
I may be missing something big, but I'll just ask anyway: Does this mean we shouldn't expect measured IQ to be more than 90% "heritable"?
Looking at the table even the composite based on two scores is more heritable in 8th grade than 9th(correlation between the two subtests is virtually the same .680 vs .681). Perhaps the finality of the 9th grade tests means outside pressure has a slightly greater influence.
Thanks for providing the analysis. In what is an easy to understand and interpret formula. As suspected genetics do matter, as some of us have come to realise over time. It's not just, or primarily physiological environmental factors that determine how well we do, though obviously physiological environmental evolutionary adaptations do make a difference. I'm thinking psychological and sociological environmental adaptations too. Not just the physiological ones. It would seem from the studies that "Like seeks like" from an evolutionary adaptive sense and benefits the offspring and future generations in an adaptive way in the main.
> Since they don't know if these are MZ or DZ, usually the estimate is made they are about 50-50 (for same-sex, because 67% twins are DZs, but only 50% of those are same-sex)
In Europeans, hopefully? I understood that the rate of MZ twins was more or less constant cross-racially, but the rate of DZ twins is not.
Hey, kicker guard I have a question.I know you've written studies in the past about mental health.But I found a recent study claiming that the disparity between conservatism liberals disappears.When you account for things like mood is this true https://sites.tufts.edu/cooperativeelectionstudy/2024/04/09/do-conservatives-really-have-better-mental-health-perhaps-not/
"Mento" at the Marginal Revolution blog summarises Scott Alexander's post as:
"Scott Alexander thinks the “heritability gap” is real but mostly on the measurement side. He thinks classical twin/pedigree/adoption numbers (~0.5–0.7 for IQ) will hold but that somehow molecular biology tools and methods are today not yet able to evidence it, so it’s still an open question. More progress is needed."
So, no need to read the SA wall of text.
I can't like this without subscribing, but I can comment, so this comment means "like"
sqrt(0.852*0.852)=1.174?
only the top mind here
You mentioned adjustments for Reliability, which I think means how close someone's score is when he takes a test over again the next day. When people talk about heritability estimates for IQ, is it standard to adjust for reliability? (it should be)
"For example, studies on the WAIS-R showed test-retest reliability coefficients of 0.86, 0.85, and 0.90 for Verbal, Performance, and Full-Scale IQs respectively, in a sample of older individuals. "
I may be missing something big, but I'll just ask anyway: Does this mean we shouldn't expect measured IQ to be more than 90% "heritable"?
Those are my thoughts exactly. It seems that puts a ceiling on heritability, but maybe someone else knows better.
That’s test-retest reliability, but I believe the post is referring to internal reliability.
Looking at the table even the composite based on two scores is more heritable in 8th grade than 9th(correlation between the two subtests is virtually the same .680 vs .681). Perhaps the finality of the 9th grade tests means outside pressure has a slightly greater influence.
Thanks for providing the analysis. In what is an easy to understand and interpret formula. As suspected genetics do matter, as some of us have come to realise over time. It's not just, or primarily physiological environmental factors that determine how well we do, though obviously physiological environmental evolutionary adaptations do make a difference. I'm thinking psychological and sociological environmental adaptations too. Not just the physiological ones. It would seem from the studies that "Like seeks like" from an evolutionary adaptive sense and benefits the offspring and future generations in an adaptive way in the main.