Posted on May 24, 2017, 6 a.m.
Researchers have discovered 52 genes linked to human intelligence, 40 of which have been identified as such for the very first time.
A group of geneticists from around the world have teamed up to analyze 13 studies with extensive genetic profiles. They also studied IQ test results for nearly 80,000 individuals with European descent. Their work was recently published in the popular journal Nature Genetics.
The Study Results
The above-referenced research team found 52 gene variants tied to intelligence. 40 of these variants were not accounted for in previous studies. The 40 new genes they pinpointed were involved in neuron differentiation and the creation of synapses that lead to comparably high intelligence. The research team reports these specific genetic factors might explain upwards of 20 percent of variance in human intelligence based on standardized intelligence tests.
Why the Findings Matter
Danielle Posthuma, a researcher with the Center for Neurogenomics and Cognitive Research, served as one of the study's main authors. She reports the team's findings are important as it is the first time a considerable number of genetic effects in human intelligence have been pinpointed. The finding held water even following the correlation of IQ with the recently identified gene variants within an extensive database that was not utilized in the study. It will be a while until the massive level of data and computing power necessary to sort through millions of genomes to pinpoint relevant genes is available.
Posthuma states that there are thousands of genes involved in human intelligence. Yet her team has identified the 52 most essential genes. Plenty more will be identified as time progresses.
Geneticists have estimated that about half of measured intelligence is determined by genetics. Yet it will be difficult to create a simple IQ test centered on an extensive list of DNA bits. At the moment, researchers like Posthuma are examining genetic effects in a completely isolated manner. Perhaps there is a specific pattern of genetic variants that makes an individual more intelligent.
Points of Interest
It is interesting to note that individuals with the so-called “smart genes” were much more likely to spend more time in school. These individuals were also more likely to be taller and have a larger cranium in infancy. They were also more likely to be autistic. Those with “smart genes” were less likely to be depressed, develop Alzheimer’s and smoke. Those without the “smart genes” suffered schizophrenia at particularly high rates. They were also more likely to be obese.
Suzanne Sniekers et al, Genome-wide association meta-analysis of 78,308 individuals identifies new loci and genes influencing human intelligence, Nature Genetics (2017). DOI: 10.1038/ng.3869