As neuroscience strives for generalizability and equity, understanding human brain diversity across populations is crucial. To uncover how ethnicity/race-related differences in the brain functional connectome arise without falling into biological essentialism, Prof. Tianyi Yan and Prof. Guoyuan Yang’s team from the Beijing Institute of Technology recently published a study in Research. Using multimodal and behavioral data from the Human Connectome Project (HCP), they constructed a multi-layered framework to systematically reveal the driving mechanisms behind this population diversity.

Anatomy acts as the "baton" for function. The researchers found that ethnicity/race-related differences in brain functional topography and functional connectivity patterns follow a hierarchical sensorimotor–association (S–A) axis. More importantly, these functional variations are strictly constrained by the brain's physical anatomy, indicating that macroscale functional diversity is deeply rooted within the brain's fundamental structural architecture.

Lifestyle serves as a bridge shaping population differences. Through structural equation modelling, the team discovered that lifestyle factors—particularly educational level and substance use—significantly mediate the associations between ethnic/racial groups and brain functional connectivity. These social experiences "physically" embed into and reshape the brain's functional connectome, specifically modulating top-down control hubs like the insula, prefrontal, and anterior cingulate cortices.

Gene expression draws the "underlying logic" at the microscale. Using the Allen Human Brain Atlas, the team revealed that the spatial distribution of these functional variations highly correlates with specific cortical gene expression patterns (enriched in synaptic signaling and nervous system development). Interestingly, these genes exhibit minimal overlap with known genetic ancestry-driven profiles, implying that the observed macroscopic differences are largely driven by postnatal environmental exposures rather than purely innate genetic determinism.

Towards a more equitable neuroscience. This study demonstrates that trans-ethnic differences in brain function are not a singular biological destiny. Instead, they are dynamic products founded on anatomy, supported by genes, and heavily sculpted by social environments. This framework helps future research avoid essentialist biases against marginalized groups and lays a solid theoretical foundation for developing truly equitable precision medicine.

The complete study is accessible via DOI: 10.34133/research.1143