Taming foxes for six generations shrank their aggression neurons

From wild to mild: Friendly foxes show changes in brain region

Cornell researchers compared brain tissue from tame, aggressive, and wild silver foxes bred in a Siberian experiment that began in the late 1950s. In the ventromedial hypothalamus, a region linked to aggression, the tame foxes had fewer neurons expressing estrogen receptor alpha — the same cells that trigger attack behavior when activated in mice. The finding suggests domestication can rewire brain structure within just a few generations.