The new genetics of intelligence

Abstract

Intelligence — the ability to learn, reason and solve problems — is at the forefront of behavioural genetic research. Intelligence is highly heritable and predicts important educational, occupational and health outcomes better than any other trait. Recent genome-wide association studies have successfully identified inherited genome sequence differences that account for 20% of the 50% heritability of intelligence. These findings open new avenues for research into the causes and consequences of intelligence using genome-wide polygenic scores that aggregate the effects of thousands of genetic variants. In this Review, we highlight the latest innovations and insights from the genetics of intelligence and their applications and implications for science and society.

Accounting for the shared environment in cognitive abilities and academic achievement with measured socioecological contexts

“…Genome-wide association studies are identifying an increasing number of specific genetic variants that account for non-trivial proportions of variance in cognitive abilities (Davies et al, 2011;Deary et al, 2012;Okbay et al, 2016;Sniekers et al, 2017;Trzaskowski, Yang, Visscher, & Plomin, 2014), with the discrepancy between the latent estimate of heritability from twin and family studies and the proportion of variance accounted for by measured genetic variants commonly referred to as the 'missing heritability gap' (Manolio et al, 2009). As more variants related to cognitive ability are discovered, the missing heritability gap for cognitive ability narrows (Plomin & von Stumm, 2018). Thus, just as genetic association studies aim to identify specific, measurable constituents of latent heritable variance in a phenotype, the current project aims to identify measurable characteristics of children's environments that account for latent shared environmental variance in cognitive abilities and academic achievement.…”

A genome‐wide association study‐derived polygenic score for interleukin‐1β is associated with hippocampal volume in two samples

“…Third, the IL-1β GWAS only included 3,309 individuals, which limits the power to identify all meaningfully associated SNPs. As has been observed with other phenotypes (e.g., educational attainment; Plomin & von Stumm, 2018), vastly larger GWASs will be needed to develop more precise polygenic scores for IL-1β. Lastly, as cytokine levels were not measured in our samples, we were not able to validate the functionality of the IL-1β polygenic score or examine how it correlates with other pro-inflammatory markers.…”

Translating Research Findings in Genetics of Learning Disabilities to Special Education Instruction

“…Parents need to be ensured that no “genetic score” is an equivalent to genetic programming from birth. An illustrative example can be taken from the Plomin and von Stumm's () study in which a young person with the second highest genome‐wide polygenic score for intelligence only performed slightly above average on the end of the high school high stakes achievement test. Conversely, an individual with the eighth‐lowest “genetic score” had an achievement score above the 75th percentile.…”