The Old Mammalian Brain or Limbic System evolved with the rise of the mammals. It is the layer or area of the human brain that houses our perceptual or emotional level of intelligence. This mind-processing center responds to perceptual inputs and controls emotional responses. Our perceptual level of intelligence receives inputs and communicates responses through facial expressions, body language, gestures, touch, and nonverbal vocal cues. While, in general, perceptual communication involves the transfer of emotional information at a subconscious level between two people, for lovers, the emotional communication is usually much deeper and incorporates vital messages about the balance of the relationship. When a line of connection moves out of balance, it is through perceptual communication that we disclose the associated pain and disappointment. Interestingly, in a true love relationship, where nearly all lines of connection are at equilibrium, any disconnect or movement from balance stands out like a sore thumb.
Around 150 million years ago, the foundation of the Limbic System or “emotional brain” or “Old Mammalian Brain” evolved in mammals. Highly specialized memory combined with emotions to produce what might have been the first true feelings. The physical structure of the Limbic System consists of the Amygdala, Hippocampus, Hypothalamus, and the Thalamus. As with the evolution of the earlier Hindbrain, the Limbic System most likely grew in layers over the next 100 million years, whereby, with the addition of each new emotional communication ability and group social dynamic, a new physical layer of growth was recorded. Although instinctual intelligence continued to make snap judgments on survival and mating behaviors, acceptance of dominance, cooperation, recognition of individuals, and expressions of intentions, complex learning, and teaching were all new behaviors processed in the Limbic System and enacted through perceptual intelligence.
We humans communicate with each other through our advanced level of perceptual intelligence on a continual basis and nowhere are these communications more prevalent than in the realm of romantic love. Our emotions connect with others and relay tremendous amounts of information without evoking conscious thought.
With these new rooms in the house of the brain, perceptual intelligence advanced for over 50 million years in dramatic fashion and produced more complex emotional and social based behaviors until, within the primate family, one animal stood up to be counted, the Hominid.