By comparing brain maps of identical twins (same genes) with fraternal twins (which share about half their genes), UCLA scientists calculated that myelin integrity (related to the speed of nerve impulses) is genetically determined in many brain areas important for intelligence.

Identifying the genes that promote high-integrity myelin could lead to ways to enhance the genes’ activity or artificially add the proteins they code for. This may in turn provide therapies for multiple sclerosis, autism and attention deficit disorder, which are associated with degraded myelin, or for intelligence enhancement in anyone.