#heritability

Highlights

Specific cognitive abilities (SCA) are 56% heritable, similar to g.

Some SCA are significantly more heritable than others, 39% to 64%.

Independent of g (‘SCA.g’), SCA remain substantially heritable (∼50%).

SCA do not show the dramatic developmental increase in heritability seen for g.

Genomic research on SCA.g is needed to create profiles of strengths and weaknesses.

Abstract

Most research on individual differences in performance on tests of cognitive ability focuses on general cognitive ability (g), the highest level in the three-level Cattell-Horn-Carroll (CHC) hierarchical model of intelligence. About 50% of the variance of g is due to inherited DNA differences (heritability) which increases across development. Much less is known about the genetics of the middle level of the CHC model, which includes 16 broad factors such as fluid reasoning, processing speed, and quantitative knowledge. We provide a meta-analytic review of 747,567 monozygotic-dizygotic twin comparisons from 77 publications for these middle-level factors, which we refer to as specific cognitive abilities (SCA), even though these factors are not independent of g. Twin comparisons were available for 11 of the 16 CHC domains. The average heritability across all SCA is 56%, similar to that of g. However, there is substantial differential heritability across SCA and SCA do not show the developmental increase in heritability seen for g. We also investigated SCA independent of g (SCA.g). A surprising finding is that SCA.g remain substantially heritable (53% on average), even though 25% of the variance of SCA that covaries with g has been removed. Our review highlights the need for more research on SCA and especially on SCA.g. Despite limitations of SCA research, our review frames expectations for genomic research that will use polygenic scores to predict SCA and SCA.g. Genome-wide association studies of SCA.g are needed to create polygenic scores that can predict SCA profiles of cognitive abilities and disabilities independent of g.

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also is there a such thing as entire families having ADHD?? cause after hearing the symptoms and taking an online test (not yet the more "official" one) I'm wondering if my parents and brother (even some extended family members) also have it and/or some form

Sent April 9, 2024

ADHD is highly heritable, so I would not be surprised if a family had multiple people who met the criteria and many others who came close.

Followers, how many people in your family have been diagnosed with ADHD? How many probably meet the criteria but aren’t diagnosed? How many have a bunch of traits but don’t quite hit the diagnostic threshold?

My great grandma had my grandpa when she was 43 and my great grandpa was 54 (in 1921!). Then my parents had me when my mom was 40 and my dad was 43. So if me and my sister's genes are a little wonky. Like. Duh.

This isn't to say older adults shouldn't have children, but it's important to know the risks and be on the lookout for potential symptoms of genetic disorders in your kids. Some mutations are harmless, even beneficial, but some are debilitating and/or life-threatening.

Artificial Selection -- humans changing a species by breeding for certain traits

Heritability -- ability of a trait to be passed down from one generation to the next

Natural Selection -- mechanism by which individuals inheriting beneficial adaptations produce more offspring than others

Population -- all individuals of a species in an area

Fitness -- ability to survive and produce offspring

Variation -- difference in physical traits of an individual compared to others in its group

Adaptation -- feature that allows an organism to better survive

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ABSTRACT