The Group: On George Price
Hamilton was neither the first nor the last to try to understand altruism through family relationships; the term "kin selection" was actually coined by John Maynard Smith, and the legendary population geneticist J.B.S. Haldane is said to have been deep into his cups at a pub when he exclaimed, "I'll jump into a river for two brothers and eight cousins!" But it was Hamilton's rule that became the standard in the field. His simple equation, rB > C, postulated that behavior that appears to disadvantage the individual (C) could emerge were it outweighed by the fitness benefit (B) it conferred to kin depending on the closeness of their relation (r) or, more basically, on the proportion of genes shared by both parties. Hamilton's theory of inclusive fitness was a riposte to what he considered the naïve and "wooly" group selectionism in vogue until the late 1960s, which explained altruistic behaviors with vague gestures toward "the good of the species."
Price was frightened by the implications of Hamilton's theory: that there must be a genetic tendency toward altruism, one that could have evolved only in favorable conditions, and that human altruism might be merely a jest played by genes, a fiction written by nature to conceal its own selfish ends. He wrote to Hamilton requesting a reprint of the paper; Hamilton hadn't any left, and he would soon be departing to study multiqueen wasps in Brazil, which put their correspondence on hiatus. Price read, in the meantime, and worked, sorting through his ideas: kin selection could explain the instinct to care for offspring and relatives, but what about sacrifice and cooperation within a herd or a pack? Could unrelated altruists somehow find one another and work together to propagate their kind?
Price considered the group selection maligned by Hamilton and his contemporaries. Hamilton's reasoning, he decided, was flawed: natural selection could operate on groups whether or not they were family, and in order to map mathematically the conditions for the emergence of altruism, one needed a tool that sorted group association without measuring common ancestry. The result was a covariance equation that showed how selection could work on any two levels at the same time—gene and individual, individual and group, and so on. Its utility was in its simplicity; it was a mathematical tautology that showed that altruism could evolve when groups developed a certain character, altruistic or selfish, provided that selection was stronger between groups than within them; selfish individuals might get the better of selfless ones, but altruists working together could best a group of uncooperative alphas.
In 1969, after Hamilton returned from Brazil with two adopted children in tow, Price wrote to him again. He explained how he had tried to rederive Hamilton's equation for kin selection and had come up with his own formula; after showing it to Cedric Smith, Hamilton's former supervisor, he had been given an office and an honorarium at the Galton Laboratory, the storied institute for the study of human genetics that was named for Darwin's cousin, the eugenicist Sir Francis Galton. Price wanted to alert Hamilton to his finding that kin selection couldn't account for altruistic acts toward lesser relatives or groups as a whole, and to give Hamilton a chance to publish a correction. On the phone the next day, Price told Hamilton that the covariance equation had taken him by surprise—that it was "quite a miracle." "Have you seen how my formula works for group selection?" Price asked, in a voice Hamilton would recollect as "squeaky and condescending." Hamilton didn't recall exactly how he responded: "I told him, of course, no, and may have added something like: 'So you actually believe in that do you?'"
After several months had passed, Hamilton was moved to write a letter to Price. "I am enchanted with your formula," he declared. "I really have a clearer picture of the selection process as a result. In its general form I can see how we might use your formula to investigate 'group selection.'" Hamilton devised a plan to ensure that Price's equation would be published in Nature, which had previously rejected his inquiry: Hamilton would send a related article to the editor and wait for a response. When it was accepted, Hamilton would withdraw the paper, saying he could not in good conscience allow it to be published while the matter of Price's paper, upon whose math Hamilton had relied, was unresolved. Hamilton's generous and ingenious ploy was successful; Nature published Price's "Selection and Covariance" in August 1970.
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Price's equation had been a revelation, to himself and then to Hamilton, but it was only the first of many. "About the beginning of June," Price wrote to his brother in the autumn of 1970, "I happened to notice one surprising coincidence in my life, and this started me searching back through my calendar books and letters and other material, and noticing a long succession of other improbabilities, until the improbability level became astronomical." He calculated the odds that all the coincidences in his life should occur: they were 1/1030, of a magnitude so shocking that he had to "give in and admit that God existed." On June 14, Price left his apartment and walked into All Souls Church. He was an eager and extreme convert, pumping the pastor and Scriptures for answers. When he discovered that his father had been a Jew, it only deepened his conviction that he and everyone else were living according to God's master plan. He was also certain that if in all the years of evolutionary research, he rather than the great minds of the profession had discovered his equation, God must have chosen him to do so.
He read feverishly, discovering discrepancies in the Gospels and filling in holes: the maternal lineage of Jesus; the true meaning of the number 666. Finally he deduced that the days of the Holy Week had been twelve rather than the traditional eight, and thus the date of Christ's resurrection was entirely wrong. He used his privileged access to such secrets to woo several women who didn't want him, including, eventually, Julia, his former wife.
While in the grip of his religious mania, Price made two other significant contributions to evolutionary theory. He helped Maynard Smith, who had spent some time working with faculty at the University of Chicago, develop the application of game theory. Price also solved Fisher's Fundamental Theorem, which states that "the rate of increase in fitness of any organism at any time is equal to its genetic variance in fitness at that time." Students puzzling over the theorem since its publication in 1930 had understood it to mean that natural selection would always increase the fitness of a given population; Price showed that, despite the infelicities of R.A. Fisher's math, the theorem was basically correct but limited to genes that interacted neither with each other nor with the environment. The theorem was far less important than Fisher had thought, but no matter: Price was busy arguing with Henry Morris, "the father of creationism," about whether the Flood had indeed covered the whole of the earth.
Yet his religious discussions were leading him, paradoxically, away from the Word. Convinced that if God meant him to live, He would care for his servant, Price began to relinquish worldly concerns: he failed to renew his grant or his visa, stopped taking his thyroid medication and ate as little as possible. In October 1972 he wrote gleefully to Maynard Smith that he was down to his last 15 pence and looking forward to the day it would disappear. By December he was in the hospital, recovering from a collapse; he was pale and feeble, his brittle fingernails darkening to black.
Despite his infirmity, Price was elated to have survived God's test, and soon underwent a second conversion. He had been a "Christian Pharisee," he wrote to Hamilton. He now understood that it didn't matter what the true date of Easter was, only when people observed it; it was people who mattered to God, not the Book. He dropped his work in the Scriptures, and in March ventured into the streets seeking vagrants in need. "My name is George," he'd tell them. "Is there any way I can help you?" But a quid here and there or a cup of hot cider proved not nearly enough; Smoky and Peg Leg Pete were among the drunk and downtrodden who soon took up residence in his flat.