Ian Deary, Lars Penke and Wendy Johnson

The neuroscience of human intelligence differences

Nature Reviews Neuroscience

Neuroscience is contributing to an understanding of the biological bases of human intelligence differences. This work is principally being conducted along two empirical fronts: genetics - quantitative and molecular - and brain imaging. Quantitative genetic studies have established that there are additive genetic contributions to different aspects of cognitive ability - especially general intelligence - and how they change through the lifespan. Molecular genetic studies have yet to identify reliably reproducible contributions from individual genes. Structural and functional brain-imaging studies have identified differences in brain pathways, especially parieto-frontal pathways, that contribute to intelligence differences. There is also evidence that brain efficiency correlates positively with intelligence.