The genetics of specific cognitive abilities.

Area of Science:

• Behavioral Genetics
• Cognitive Psychology
• Psychometrics

Background:

• Research on cognitive ability differences often centers on general cognitive ability (g).
• The genetic underpinnings of specific cognitive abilities (SCA) within the Cattell-Horn-Carroll (CHC) model are less understood.
• Heritability of g increases with development, but developmental trends for SCA are unclear.

Purpose of the Study:

• To conduct a meta-analytic review of the heritability of specific cognitive abilities (SCA).
• To investigate the heritability of SCA independent of general cognitive ability (SCA.g).
• To inform future genomic research on cognitive abilities.

Main Methods:

• Meta-analysis of 747,567 twin comparisons from 77 publications.
• Analysis focused on 11 of the 16 middle-level CHC factors (SCA).
• Investigation of SCA variance independent of g (SCA.g).

Main Results:

• Average heritability for SCA is 56%, comparable to g.
• SCA exhibit differential heritability and do not show the developmental increase seen in g.
• SCA.g remain substantially heritable (average 53%) even after accounting for shared variance with g.

Conclusions:

• Specific cognitive abilities (SCA) are significantly heritable.
• SCA independent of general cognitive ability (g) also demonstrate considerable heritability.
• Further research, including genome-wide association studies, is needed to understand the genetic basis of SCA and SCA.g.