There is one grand design for the brains of all mammals, fish, birds, amphibians, and reptiles, which was established nearly 300 million years ago and has been evolving ever since. Just as cars have evolved into different versions, sedans, SUVs, sports cars, etc., that rely on many of the same underlying parts, all vertebrate brains have similar parts that do similar things but that are well adapted to the needs of their own particular species. For example, birds have superior occipital lobes because they need to spot prey (and predators) from great heights. While we humans think of ourselves as superior overall because we overemphasize the importance of our own advantages, other species could justifiably make the same claims on their own behalf, birds for flight, eyesight, and instinctual magnetic navigation; most animals for smell; and several for appearing to have particularly enjoyable sex.
This “universal brain” has evolved from the bottom up, meaning that its lower parts are evolutionarily the oldest and the top parts are the newest. The brainstem controls the subconscious processes that keep us and other species alive, heartbeat, breathing, nervous system, and our degree of arousal and alertness. The next layer up, the cerebellum, gives us the ability to control our limb movements by coordinating sensory input with our muscles. Then comes the cerebrum, which includes the basal ganglia (which controls habit) and other parts of the limbic system (which controls emotional responses and some movement) and the cerebral cortex (which is where our memories, thoughts, and sense of consciousness reside). The newest and most advanced part of the cortex, that wrinkled mass of gray matter that looks like a bunch of intestines, is called the neocortex, which is where learning, planning, imagination, and other higher-level thoughts come from. It accounts for a significantly higher ratio of the brain’s gray matter than is found in the brains of other species.
Meaningful work and meaningful relationships aren’t just nice things we chose for ourselves, they are genetically programmed into us.
Neuroscientists, psychologists, and evolutionists agree the human brain comes pre-programmed with the need for and enjoyment of social cooperation. Our brains want it and develop better when we have it. The meaningful relationships we get from social cooperation make us happier, healthier, and more productive; social cooperation is also integral to effective work. It is one of the defining characteristics of being human.
Leonard Mlodinow, in his excellent book Subliminal, writes, “We usually assume that what distinguishes us [from other species] is IQ. But it is our social IQ that ought to be the principal quality that differentiates us.” He points out that humans have a unique ability to understand what other people are like and how they are likely to behave. The brain comes programmed to develop this ability; by the time they are four years old, most children are able to read others’ mental states. This sort of human understanding and cooperation is what makes us so accomplished as a species. As Mlodinow explains, “Building a car for example requires the participation of thousands of people with diverse skills, in diverse lands, performing diverse tasks. Metals like iron must be extracted from the ground and processed; glass, rubber, and plastics must be created from numerous chemical precursors and molded; batteries, radiators and countless other parts must be produced; electronic and mechanical systems must be designed; and it all must come together, coordinated from far and wide, in one factory so that the car can be assembled. Today, even the coffee and bagel you might consume while driving to work in the morning is the result of the activities of people all over the world.”
In his book The Meaning of Human Existence, Pulitzer Prize–winning author Edward O. Wilson surmises that between one million and two million years ago, when our ancestors were somewhere between chimpanzees and modern homo sapiens, the brain evolved in ways supporting cooperation so man could hunt and do other activities. This led the centers of memory and reasoning in the prefrontal cortex to develop beyond those of our primate relatives. As groups became more powerful than individuals and our brains evolved in ways that made larger groups manageable, competition between groups became more important than competition between individuals and groups that had more cooperative individuals did better than those without them. This evolution led to the development of altruism, morality, and the sense of conscience and honor. Wilson explains that man is perpetually suspended between the two extreme forces that created us: “Individual selection [which] prompted sin and group selection [which] promoted virtue.”