Some human acts, like donating a kidney to a stranger, seem to be genuinely altruistic, motivated by no other reason than wanting to help someone else in need. At the same time, a lot of human behavior seems to be entirely selfish. So are we by nature altruistic, or selfish? And what role did our evolutionary past play in shaping our moral outlook? The answer is darker than you might think, writes Barry Lam. We evolved to recognize what’s morally good, but not to be motivated by it.

Between two hundred and four hundred people a year annually in the US donate a kidney to a stranger, many without ever meeting the recipient. About 4000 people give to effective altruism organizations totaling $260 million annually. Billions of dollars in estate wealth are bequeathed to charitable organizations upon the death of the donor.

On the other hand, even more billions of dollars in excess wealth are placed in trusts to benefit only a person’s descendants, sometimes for an indefinite number of generations. The amount spent annually on effective altruism is dwarfed by the $382 billion a year humans spend on cosmetics. Approximately 299,999,700 people in the US do not donate a kidney while 100,000 wait, often until death. If true altruism is self-sacrificial activity on behalf of strangers, we will find millions of small acts of altruism in human life, as well as billions of missed opportunities to act selflessly. So, are humans by nature altruistic, or selfish? Did we evolve to be good Samaritans, or self-interested bastards?

Evolutionary theorists have offered interesting competing answers to this question. One option is to explain away altruism as ultimately self-interest in disguise. Like everything else in the plant and animal kingdom, the story goes, humans have a drive for self-sacrificial behavior only when it benefits the reproduction of their own genes.  Or maybe humans are truly exceptional in the natural world, having developed thought processes motivating them to act self-sacrificially to no reproductive advantage to their genes. However, it’s a third, more provocative hypothesis about human altruism that I think is the most probable. Humans have evolved to be neither truly altruistic nor fundamentally self-interested. They have evolved to be hypocrites. Having developed a liking for the altruistic behavior of others, humans, at the same time, did not evolve to be themselves motivated by true altruism.

Beyond nature’s version of  altruism?

In his recent book, Kindness to Strangers, evolutionary psychologist Michael McCullough surveys recent human history to make the case that human altruism has now evolved to be different in kind, not just degree, to animal altruism. Self-sacrificial activity that is regularly observable in the natural world can always be explained in terms that ultimately benefit a creature’s genes. For McCullough, if humans were solely motivated to act altruistically by these same mechanisms, we would never see the rise of the welfare state, foreign aid, effective altruism, or altruistic kidney donation. Instead, argues McCullough, the origins of these kinds of activity in people who participate in and endorse them, are found in arguments appealing to impartial moral principles aimed at the common good for humanity. For McCullough, it is the mind’s capacity for prudential and moral reasoning that explains the recognition of such moral principles, and therefore the actions motivated by those principles. And this capacity for reasoning is the result of evolution: “I think it's a mistake to think of our evolved instincts for reciprocity and favoritism for kin as the evolutionary explanation, and reasoning as the sort of non-evolutionary explanation, the non-naturalistic ” says McCullough to me in an interview, “I think they're ultimately both reducible to the action of natural selection building design into the human mind. Our capacity for reasoning is in itself a direct product of natural selection's action on the human mind. Reasoning is every bit as naturally selected as any of those things.”

Self-sacrificial activity that is regularly observable in the natural world can always be explained in terms that ultimately benefit a creature’s genes.

It is undeniable that moral and prudential reasoning plays a role in motivating the truly altruistic acts we see, like altruistic kidney donation. The reason altruistic kidney donors give a kidney is because someone needs a kidney to survive, and the donor herself does not need two to survive and live well. But to turn this observation into an argument that natural selection can explain acts of true altruism is a stretch.

Consider the example that many people, particularly in wealthier countries, decide to have no children. There are a variety of explanations for this phenomenon. One very natural place to look is human reason. For prudential reasons, given the availability of birth control and quality of life considerations, people have decided against procreating. One place it would be questionable to look for an explanation of this phenomenon is evolution by natural selection. For one, the existence of some people who have no children does not make this particular trait prevalent enough to demand an evolutionary explanation. It is not true that humans, by nature, are not having children. In fact, the opposite is true. Secondly, evolutionary explanations are the wrong place to look for explaining why some people don’t have children. Evolution explains the sexual drive to have children, not the outlier cases of the refusal to have children. Whatever explains why people refuse to have children, it is a rather safe theoretical assumption that such a trait runs contrary to evolutionary explanations. Thus, even if there is an explanation of the origins of human reason, and human reasoning is responsible for a decision not to have children, it does not follow that we thereby have an evolutionary explanation for decisions not to have children.

We evolved to select altruists

I see human altruism, true altruism that is irreducible to self-interested behavior, in very similar ways. Acts of true altruism are generally contrary to the drives selected for naturally. But it does not follow that McCullough doesn’t have a point. The ideal of true altruism might very well be naturally selected for, but not in the way McCullough thinks. If we are supposed to explain the exhibition of truly altruistic behavior, there is nothing for evolution to explain. But if we are supposed to explain the endorsement and admiration of truly altruistic behavior in humans, that is a far more widespread feature of human beings, and far more conducive to evolutionary explanation. We are not, generally and by nature, altruistic. But we are, generally and maybe by nature, praising of the altruistic.

We are not, generally and by nature, altruistic. But we are, generally and maybe by nature, praising of the altruistic.

Philosopher Kieran Setiya makes this point in my recent podcast episode of Hi-Phi Nation, and in his book Knowing Right from Wrong. Setiya holds the view that a person’s moral values concern what a person finds admirable, morally worthy, and praiseworthy in others, and not necessarily the reasons that form the basis of their own actions. For Setiya, moral knowledge and moral values are not necessarily about figuring out what I should do. Nor are they things that are supposed to explain my own motivations in action. Rather, my moral values are about what moral characteristics I find obligatory or admirable in other people, the people I must live with in the same world. Setiya argues that, if this is what moral values are, a very good case can be made that humans are disposed, by their very nature, to know right from wrong. This is because humans are disposed, by their very nature, to see as morally virtuous those traits that make a person someone they want to live and commune with. And everyone, from the lowliest gangster to the saintliest servant will want to live amongst and commune with someone who will sacrifice a kidney to save their life. It makes perfect sense that humans evolved a moral sense that altruism is a good thing. Valuing altruism in other people means we will be more apt to praise, admire, and want to be around people who exhibit such a trait. That’s because it is far more advantageous to us than surrounding ourselves with wholly self-interested, self-serving people who are only thinking about propagating their own genes.

It makes perfect sense that humans evolved a moral sense that altruism is a good thing.

According to this evolutionary picture, human beings are hypocrites par excellence, developing one set of standards for the evaluation of others, while adopting a set of behaviors completely contrary to those standards. The most advantageous circumstance for the propagation of my genes is that I be allowed to be self-centered amongst the truly altruistic, so that they will aid me at great cost to themselves. This kind of moral hypocrisy, however, is not a stable trait to have in a population. Not everyone can be a free rider. You cannot have populations of people only admiring altruism but not being altruistic, for it would then be impossible to surround yourself with truly altruistic people, and the advantage to having altruistic moral standards disappears.  It is also not a perfectly comfortable position to be in, always advocating for others to abide by standards you do not satisfy yourself. Thus a number of people will have to be truly altruistic people both in their acts and their moral standards.

In a population of nothing but hypocrites, it does not pay to be a hypocrite. But in a population of nothing but altruists, the hypocrite reproduces like crazy.

On the other hand, a population of true altruists cannot survive the invasion of free-riding mutants, who demand self-sacrificial acts from the true altruists, but give nothing back, thereby reaping all benefits and paying no costs. They will reproduce like crazy and crowd out the true altruists. The result is that in a population of nothing but hypocrites, it does not pay to be a hypocrite. But in a population of nothing but altruists, the hypocrite reproduces like crazy. It follows that, within a large enough population, there is going to be an equilibrium of true altruists and true hypocrites. Let us hope, for the sake of everyone that needs a kidney, that we have not reached that equilibrium yet.

Season 5 of the Hi-Phi Nation podcast contains an episode about altruistic kidney donation, which forms the basis of this essay.