Sexually selected Peacock's tail

I observed that prison society is arranged vertically and that the core interaction is dominance and submission. I clearly remember when my first major insight struck me. I was at a routine meeting with a group of inmates, heatedly discussing a recent incident. I suddenly recognized that it was as if I was sitting inside a functioning mind. One inmate was acting out the role of id, another the role of superego, and I was the mediating ego. The insight was that by means of some evolutionary process, the interactively dynamic human mind (superego-id, thinker-thinkee) was the result of the internalization into a single individual of the dominance-submission social relationship so emblematic of all primate species.

            I subsequently became fascinated with Darwin’s observation of sexual selection. He was less interested in intrasexual selection—males competing with each other for access to females—so much as in inter- or “epigamic” sexual selection, in which females select traits in males that have no apparent survival value. He goes on about these spectacularly curious male traits in birds:

They charm the female by vocal or instrumental music of the most varied kinds. They are ornamented by all sorts of combs, wattles, protuberances, horns, air-distended sacs, topknots, naked shafts, plumes and lengthened feathers gracefully springing from all parts of the body. The males sometimes pay their court by dancing, or by fantastic antics performed either on the ground or in the air.

Darwin just made the observation that females selected these apparently useless traits, but gave no explanation as to how or why this could happen. Then in the 1920s a brilliant English polymath named Ronald Fisher grappled directly with this odd phenomenon, and realized something that has had a central influence on my own thinking. He faced squarely that the females in this scenario were actually competing with each other for the ability to select these odd traits in males.

His revolutionary insight was that the wholly mental capacity within these females to select traits in males was itself subject to natural selection. He further proposed that the reason that these odd traits were selected was that they were indications, or what I like to call advertisements, of the male’s fitness. He then theorized that once this cycle got going, the daughters of such competitive mating would possess ever-stronger inclinations to select these odd traits, and furthermore that these newly “sexy” traits in their sons would become ever more extreme in an accelerated evolutionary cycle. This cycle would be broken only when the trait became so outlandishly cumbersome (as in the classic example of the peacock’s tail) that it began to hamper the male’s actual fitness (such as the ability to get around and fly). The proper term for the showing off to females these sexually attractive traits is “sexual display.”

            I have remained enamored by the concept of sexual selection to this day. First of all this was selection taking place in the mental and emotional ability to select. This is my territory as a psychiatrist. I had learned from Freud that humans are characterized by hyper-sexuality. It would be decades before the mental illness of mania would finally convince me that Darwin’s concept of sexual display would largely distinguish human behavior from that of our hominid forbears. Moreover in retrospect, at that time in my own life, examples abounded of flagrant sexual display: a white Harley motorcycle with a red cross roaring around Manhattan during my surgical residency, then in Washington, a huge old limousine, the engine of which I painted baby-blue; the single-handed construction of a Wimbledon-grade grass tennis court in my back yard, among many other such stunts.

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