Hell is knowing the truth and not accepting it.
George R. Price
Price had set himself the ‘problem’ of explaining why humans lived in families – particularly what fatherhood was for, scientifically speaking. This, in turn, led him to the question of how altruism had evolved, and it was while studying new theories around this topic that he derived what is now called the Price equation, almost by accident.
This is what it looked like: wΔz=Cov(wi,zi). It captured the essence of evolution by natural selection in one simple formula. It describes how in a population of reproducing individuals, be they people, plants or self-replicating robots, any trait (z) that increases fitness (w) will increase in the population with each new generation; if a trait decreases fitness, it will decrease. It’s a type of statistical relationship called covariance, and it was so elegant that Price couldn’t quite believe no one had stumbled across it before.
So in September 1968, this obscure middle-aged American scientist walked in off the street to the Galton Laboratory, the home of human genetics at University College London. No one there knew who he was – he had no credentials, held no academic position and had no appointment. All he had was an equation. When he confidently proclaimed in his condescending, high-pitched voice that his equation could explain the evolution of altruism, they probably thought he was a crank. Nevertheless, when he walked out 90 minutes later, Price had a job and the keys to his own office.
He continued to hone his equation there, but at the same time began giving away his possessions. He would seek out the homeless in Soho Square or at the nearest railway stations, Euston and King’s Cross, and give them anything they asked for, from the money out of his pay packet right down to the clothes off his back. If they needed a place to sleep, he would invite them back to his flat indefinitely. Eventually he had given away so much that he became as destitute as the men he was helping. When the lease ran out on his flat, he took to squatting, moving often, somehow continuing to do research as well.
By the end of 1974, Price had given up everything. Some time before dawn on 6 January 1975, in a squat not far from Euston, he killed himself.
Told like that, it seems obvious that everything was connected – he studied the concept of family because of the way he’d left his wife and daughters; his subsequent altruism was related to the equation he discovered; his suicide was a result of his extreme altruism. But as Farnworth discovered, nothing in Price’s story is that simple.
It’s inconceivable that his choice of family as a topic was not bound up with his relationship with his children, but the evolution of social behavior – and of altruism in particular – was also one of the biggest scientific questions of the age. It was threatening to undermine Darwin’s whole theory of evolution by natural selection, which made it more than worthy of Price’s obsessive attention.
Altruism has always been a bit of a problem. Every altruist has their own motives, of course – some are emotional, responding to fellow humans in desperate straits, while others are more rational, thinking about the kind of society they’d like to live in and acting accordingly. Does that imply a level of self-interest? Even if it did, it shouldn’t undo the goodness of altruism, and yet people can be deeply suspicious of those who apparently willingly put others’ interests before their own. Selfless acts often attract accusations of hidden selfishness, suggesting they’re not really altruistic at all.
This wasn’t the problem for Darwinism. After all, humans have culture and religion and moral codes to live by – maybe our altruism was more to do with that than biology. Unfortunately, altruism was not only a human trait – it was everywhere. There were birds that nurtured other pairs’ fledglings, vampire bats that regurgitated blood for those who’d failed to feed in the night, monkeys that put themselves in danger by raising the alarm when a predator approached the rest of their troop.
It was altruistic ants that posed a particular problem for Charles Darwin. Natural selection is often described as ‘survival of the fittest’, where fitness means how successful an individual is at reproducing. If one individual has a trait that gives them a fitness advantage, they will tend to have more offspring than the others; because the advantage is likely to be passed on to their offspring, that trait will then spread through the population. A fundamental part of this idea is that individuals are competing for the resources they need to reproduce, and fitness includes anything that helps an individual reproduce more than the competition.
But as Darwin observed, ants and other social insects are not in competition. They are cooperative, to the extent that worker ants are sterile and so have literally zero fitness. They ought to be extinct, yet there they are in every generation sacrificing their own reproductive ambitions to serve the fertile queen and her drones. Darwin suggested that competition between groups of ants – queen, drones and workers together – might be driving natural selection in this case. What was good for a nest competing against other nests would then outweigh what was good for any individual ant.
Group selection, as this idea was known, was not a very good solution, though. It didn’t explain how the cooperative behavior evolved in the first place. The first altruistic ant would have been at such a huge disadvantage compared to the rest of its group that it would never have got the chance to breed more altruistic ants. The same was true of humans – natural selection was intrinsically stacked against any altruistic individual surviving long enough to pass on their altruism.
This left a rather embarrassing paradox: the evolution of altruism was impossible, yet clearly altruism had evolved. If the biologists couldn’t resolve this, would they have to throw out the whole idea of natural selection?
A young man called Bill Hamilton spared biology’s blushes with a slightly different solution in 1964. He proposed that altruism could have evolved within family groups – yes, an individual altruist would seem to be at a disadvantage, but that was not the whole picture because other individuals who shared the same genes associated with altruism would all influence each other’s ‘inclusive fitness’.
Discussions of human altruism are often framed in terms of someone drowning in a pond. Do you put your own life at risk to try and save them? If you do, that’s altruism. Hamilton’s idea, which became known as kin selection, acknowledged that compared to a selfish person who never got their feet wet, someone who went around jumping into ponds to save drowning people would be at a greater risk of dying before they managed to reproduce and pass their altruistic genes on to their children. However, if they happened to save a relative who shared the same genes, our altruist would have indirectly helped to get those genes passed on to the next generation after all. If the total benefit derived from having altruistic genes in the family, so to speak, was greater than the cost, then the evolution of altruism was no longer paradoxical.
hen George Price stumbled across Hamilton’s work in the Senate House Library in 1968, he was shocked. He was forced to confront the relationship between morality and family, the biological imperative he should have felt to sacrifice his selfish ambitions in favor of supporting his kin. He immediately set to work to challenge, even disprove Hamilton’s theory. But he could only confirm it. Along the way, he derived his equation of natural selection, which helped to prove that altruism was not selfless and moral, but rather selfish and genetic.
Here’s what the next version looked like: wΔz=Cov(wi,zi)+E(wiΔzi). The new bit on the right-hand side accounts for any effects the trait in question might have on its own transmission – if it has properties that make it more likely to be passed on than other traits. Having this extra term opened up the process to allow for more than the simple story of ‘survival of the fittest’ – this was where Hamilton’s ideas of inclusive fitness and kin selection could start to influence the course of evolution. It even allowed group selection more broadly; indeed, Price thought it meant natural selection could occur at many levels simultaneously. He wrote to Hamilton at once.
In June 1970, just a few months after Hamilton had written to say how “enchanted” he was with the equation, Price had a profound religious experience (he refused to tell his friend the details, sensing that Hamilton would be as unbelieving of such things as Price himself would have been until that point). Depressed, apparently by his role in confirming that altruism had selfish origins – though it is just as likely that he had stopped taking his thyroxine pills again – he had become obsessed with coincidences in his life, not least the sheer improbability that he, who hadn’t known “a covariance from a coconut”, should have discovered that equation. All at once, despite a lifetime of hardline atheism, he became convinced that a higher power had been at work.
The nearest church was All Souls, just above Regent Street in central London. He walked in and started praying. By the time he walked out again, he had given himself to Jesus.
At first, he brought the full weight of his intellect to bear on the Bible – he concluded that Easter week had taken 12 days, not eight, and was determined to persuade others of this truth, writing arguments as rigorous and detailed as his scientific research. Typical Price: start from first principles, take nobody else’s word for it, test it obsessively and try to find your own way to the truth.
Then, at the end of 1972, he had a second conversion. He had already decided to trust in Jesus completely. He’d stopped taking his thyroxine pills and by now his insurance money was starting to run out – but if Jesus wanted him to save him, Jesus would find a way. Around Christmas, he collapsed, close to death. A neighbor found him and he was rushed to hospital where the doctors saved his life. For Price, this was a sign that Jesus did want him to live, but also to change his ways and stop worrying about the length of Holy Week. He told Hamilton he had “sort of ‘encountered’ Jesus”. He had had a vision, in other words, and heard Jesus whisper, “Give to everyone who asks of you.”
For him, the most rational explanation available was that he had been chosen by God to discover the Price equation and to become an extreme altruist. He was happy to tell people about it, too – if he is remembered at all, one of the first things people tell you about him is that he ran through the corridors of University College London shouting that he had “a hotline to Jesus”. In some ways his life had become extremely complicated, but it was also much more simple to be willing to give up anything and everything and put all his faith in Jesus.
Of course, that isn’t the end of the story. As Farnworth sees it, Price had a third conversion shortly before he died. He finally stopped helping others. He didn’t have much more to give by this point, it’s true, but he began to pay more attention to his own wellbeing. He had realized that he needed to help himself first if he was going to be any use to anyone else. Rebuilding his life from the bottom up was a daunting task, however. Despite getting a job as a cleaner at a bank, he knew he was struggling. He made an appointment to see a psychiatrist. But then, just days before his appointment, he killed himself.
“Although the house was awaiting demolition the electricity was still on: it mightn’t have been too freezing for George when he was there all alone over Christmas,” Hamilton wrote in his memoirs. “As I tidied what was worth taking into the suitcase, his dried blood crackled on the linoleum under my shoes: a basically tidy man, he had chosen to die on the open floor, not on his bed.