" Stick recording electrodes into numerous species’ amygdalaefn9 and see when neurons there have action potentials; this turns out to be when the animal is being aggressive.fn10 In a related approach, determine which brain regions consume extra oxygen or glucose, or synthesize certain activity-related proteins, during aggression—the amygdala tops the list. "

― Robert M. Sapolsky , Behave: The Biology of Humans at Our Best and Worst