In his scheme, the limbic system evolved alongside the developing social complexity of the mammals.
The middle region, the limbic system, controls docile, loving emotions.
limbic system n.
A group of deep brain structures, common to all mammals and including the hippocampus, amygdala, gyrus fornicatus, and connecting structures, associated with olfaction, emotion, motivation, behavior, and various autonomic functions.
A group of interconnected structures of the brain including the hypothalamus, amydala, and hippocampus that are located beneath the cortex, are common to all mammals, and are associated with emotions such as fear and pleasure, memory, motivation, and various autonomic functions.