History belongs above all to the active and powerful man, to him who fights a great fight, who requires models, teachers and comforters and cannot find them among his associates and contemporaries.”
The limbic brain is an emotional magnet. Attractors activate compatible aspects of relatedness and emotionality in others, leaving dormant the incompatible pebbles. We all embody an emotional force field that acts on the people we love, evoking the relationship attributes we know best. Our minds are in turn pulled by the emotional magnets of those close to us, transforming any landscape we happen to contemplate and painting it with the colors and textures they see.
The young man with a fondness for faultfinding lovers is in even more trouble than he thinks. First, he must contend with the mental mechanism that leads him with uncanny precision to a woman who is herself critical. Second, his presence will magnify whatever minatory tendencies his current paramour may possess. Ditto for her: she has chosen her man because he matches an Attractor of hers, and she will enhance the matching virtues and vices.”
Because loving is reciprocal physiologic influence, it entails a deeper and more literal connection than most realize. Limbic regulation affords lovers the ability to modulate each other’s emotions, neurophysiology, hormonal status, immune function, sleep rhythms, and stability. If one leaves on a trip, the other may suffer insomnia, a delayed menstrual cycle, a cold that would have been fought off in the fortified state of togetherness.
The neurally ingrained Attractors of one lover warp the emotional virtuality of the other, shifting emotional perceptions—what he feels, sees, knows. When somebody loses his partner and says a part of him is gone, he is more right than he thinks. A portion of his neural activity depends on the presence of that other living brain. Without it, the electric interplay that makes up him has changed. Lovers hold keys to each other’s identities, and they write neurostructural alterations into each other’s networks. Their limbic tie allows each to influence who the other is and becomes.”
The human body constantly fine-tunes many thousands of physiologic parameters—heart rate and blood pressure, body temperature, immune function, oxygen saturation, levels of sugars, hormones, salts, ions, metabolites. In a closed-loop design, each body would self-monitor levels and self-administer correctives, keeping its solitary system in continuous harmonious balance.
But because human physiology is (at least in part) an open-loop arrangement, an individual does not direct all of his own functions. A second person transmits regulatory information that can alter hormone levels, cardiovascular function, sleep rhythms, immune function, and more—inside the body of the first. The reciprocal process occurs simultaneously: the first person regulates the physiology of the second, even as he himself is regulated. Neither is a functioning whole on his own; each has open loops that only somebody else can complete. Together they create a stable, properly balanced pair of organisms. And the two trade their complementary data through the open channel their limbic connection provides.
[…] That open-loop design means that in some important ways, people cannot be stable on their own—not should or shouldn’t be, but can’t be. This prospect is disconcerting to many, especially in a society that prizes individuality as ours does. Total self-sufficiency turns out to be a daydream whose bubble is burst by the sharp edge of the limbic brain. Stability means finding people who regulate you well and staying near them.”
Everything a person is and everything he knows resides in the tangled thicket of his intertwined neurons. These fateful, tiny bridges number in the quadrillions, but they spring from just two sources: DNA and daily life. The genetic code calls some synapses into being, while experience engenders and modifies others.
The brain thus takes shape as a compromise between unyielding limits and nearly infinite freedom. It is like a snowflake or a sonnet, whose innumerable members remain bound to an eternal integer. The polarity of water molecules constrains a snowflake to be a six-sided polyhedron, and a sonnet comprises fourteen lines. The universe does not contain a seven-sided snowflake or a sonnet with five quatrains. But within the expanse of these restrictions lie endless permutations of beauty.
In the brain, a genetic blueprint directs the raising of rough neural scaffolds that serve as the cores of various subsystems. DNA thus reins in the riotous proliferation of designs that a hundred billion cells could freely generate. One brain, one plan: no brain sports three temporal lobes, and none registers anger with an upward turn to the lips. But, as in a topiary, variety flourishes within walls. Early experience trims a scaffold’s semiadjustable outline into a neural template: an assemblage of neurons and connections fine-tuned for function in a particular environment. Genetic information lays down the brain’s basic macro- and microanatomy; experience then narrows still-expansive possibilities into an outcome. Out of many, several; out of several, one.
After the template takes form, neural flexibility wanes, but often not to zero. And here the brain is like a sonnet that undergoes eternal editorial correction or a snowflake that follows a perpetual tumbling path, always adding crystals to hexagonal wings. Ongoing experience continues to mold neural connections, ensuring that one’s personality never rests. As Heracleitus wrote several thousand years ago, “We do and do not step into the same river. We are, and are not.””
Safety, conformity, belonging. Such are the feelings of a sheep within the herd. Such is the way of the herd animal.