Brain Wiring Efficiency Links Our Genes to Intelligence

Intelligence is a potent predictor of life outcomes, yet the biological mechanisms translating our DNA into cognitive prowess have long been a black box. While scientists know that genetics play a substantial role, the specific neural pathways bridging the gap between our genome and our behaviour have been harder to pinpoint. A new study involving 434 young and older adults offers fresh insight into this complex relationship.

Researchers calculated ‘polygenic scores’—aggregate estimates of genetic predisposition—for each participant and recorded their brain activity using electroencephalography (EEG) while they were at rest. To analyse these complex signals, the team employed graph theory, a mathematical framework that quantifies the architecture of communication networks. They specifically measured metrics like ‘efficiency’ and ‘clustering’ to see how well different brain areas integrated information.

The findings revealed a clear chain of influence. Higher polygenic scores predicted distinct patterns of functional connectivity, particularly in the parieto-frontal regions of the brain. This optimised neural wiring was, in turn, strongly associated with higher general intelligence. Essentially, the study suggests that genetic variation shapes intelligence by fine-tuning the efficiency of information transfer across the brain’s networks.

This represents the first research to link polygenic scores to intelligence using EEG-derived graph metrics. By identifying these candidate pathways, scientists have laid a foundation for future hypothesis-driven investigations into the biological roots of human cognition.