Photo: Pascal Rondeau

So many of the scenes coming out of the ongoing refugee crisis in Europe have been chilling: the 71 men, women, and children whose decomposing bodies were found in an abandoned truck; the 34 who drowned when their boat capsized near a Greek island; the heart-stopping image of 3-year-old Aylan Kurdi’s lifeless body washed up on the shore of a Turkish beach.

And yet amid the horror, there’s a glimpse every now and then of incredible human kindness. In Iceland, for example, thousands have volunteered to host Syrian families, or simply to provide them with some companionship. (“I can cook for people and show them friendship and warmth,”one Icelander wrote.) And in Turkey, Fethullah Üzümcüoğlu and Esra Polat spent the money that was meant for their wedding reception on food for 4,000 Syrians. At the national level, taking in refugees is expensive — at least in the near-term — but Germany has already pledged to accept 800,000, and many of the early arrivals were met with gifts at the train station. Many other Western European countries are having intense public debates, weighing the needs of desperate foreigners against the needs of existing citizens.

Not long ago, even the consideration of such altruistic acts would have mostly mystified evolutionary biologists, as they run contrary to the idea of the “selfish gene,” the theory of natural selection that prizes self-interest over self-sacrifice for the benefit of another. The strictest understanding of the notion of “survival of the fittest” posited a simple, difficult question: How would sacrificing your own resources to help someone else provide any benefit to you? If humans are inherently selfish, it’s only because the instinct has long helped the species survive.

But a more sophisticated understanding of altruism has recently taken hold among evolutionary biologists, including David Sloan Wilson, the distinguished SUNY professor of biology and anthropology who earlier this year published the book Does Altruism Exist? (Spoiler: His answer is a resounding yes.) It’s one of many (many) books out this year exploring the subject of altruism, and one of two by scientists who argue that humans are naturally good.

Throughout much of the 20th century, altruism was often dismissed by scientists as being too rare to matter, Wilson writes. Altruistic acts were aberrations, exceptions that ultimately proved the rule. And when scientists considered it at all, the explanation would usually come back to self-interest — namely, kin selection. If you do sacrifice something of your own in order to help someone else, it’s only to protect your bloodline. The obvious example from nature here is the mama bear putting her own life at risk as she fights off a hungry coyote that’s after her young cubs.

But in his book, Wilson argues that this way of thinking about altruism is much too narrow. “I think we’ve all been brainwashed to think that everyone is selfish,” he said in a phone interview with Science of Us. “And it’s against that background that we’re surprised by altruism. I think that if we consult our everyday lives, in our everyday experiences, we experience altruism and generosity all the time.” Wilson broadens the idea of natural selection to a group level, something he calls multilevel selection. His argument is that selfishness actually undermines the common good.

His reasoning makes intuitive sense: Yes, behaving selfishly does unquestionably benefit the individual. But it doesn’t benefit the group as a whole. As evidence, Wilson references a study of water striders, those long-legged bugs that skip along the surfaces of ponds and marshes. Some of the males in the study, which Wilson refers to as “gentlemen,” would only mate with receptive females. But other males would also routinely mate with non-receptive females, a group Wilson refers to as “rapists” (a term that, while not exactly inaccurate, is definitely jarring to see applied to bug behavior).

Wilson explains the study, conducted by his former Ph.D. student Omar Elkadar:

Within each group containing both types, the rapists outcompeted the gentlemen for mates. If within-group selection were the only evolutionary force, the gentlemen would quickly go extinct. However, rapists prevented females from feeding and therefore caused them to lay fewer eggs. This effect was so large that females in groups with all gentlemen laid over twice as many eggs as females in groups with all rapists.

So this suggests, Wilson argues, that when speaking of individuals, selfish behavior does, of course, win out. But at the group level, altruism prevails. Self-interest may benefit the individual, but it often doesn’t benefit the group as a whole, and so a group that includes more individuals that act altruistically will ultimately have greater odds of survival than a group made up of more individuals that act selfishly. It’s an expansion of the idea of kin selection, then, one that includes the community at large.

But this doesn’t quite get us all the way there. According to this mode of thinking, you’re not acting explicitly for your own good, true, but your good deed does help your community; you are part of that community, and so, in that way, you (and your kin) ultimately benefit, too. “It doesn’t seem to be puzzling as to why a mother would help their child — or their extended family, or their community,” said Larissa MacFarquhar, author of the upcoming book Strangers Drowning, which is out later this month. “But it’s always your people, in some way, people who are expected — maybe not directly, but in some larger sense — to reciprocate, and to boost your own well-being somehow.” The examples I listed earlier from the migrant crisis in Europe don’t quite fit this mold; by opening up their homes, those Icelanders aren’t really acting for the good of their own group. So where do acts like these fit in, when one person reaches out to help someone else who is not a part of their community or culture?

Here’s a theory: Maybe there are a few among us who consider pretty much everyone to be part of their “group”; maybe they genuinely perceive the world as a kind of global community. The question of how people perceive others to be within their own group or outside of it is a complicated one, something political psychologists believe comes down to how authoritarian the individual is. But in her book, MacFarquhar asks the extreme do-gooders themselves, including a couple that opened a clinic to treat leprosy in rural India, or the couple that adopted 22 children (and whose story was featured in a recent New Yorker article). The difference, MacFarquhar said, seems to be that the people she profiles in her book don’t see a distinction between their own families, or their own communities, and the rest of the world. “Most of us feel that we want to give all that we can to our families,” MacFarquhar said. “And not only do we not think that’s a bad thing, we think that’s a good thing.”

So extreme altruists love their own little tribes, yes, but they also don’t believe that they deserve any more or any less than anyone else. “Most of us not only are not able, but don’t even want to come to the point where we’re willing to value strangers as much as members of our own family,” MacFarquhar said. It’s a question each person — or, in the broader case of the refugee crisis, each Western European nation — must wrestle with individually. How much good are you willing to do for a stranger, and at what potential cost to yourself?