To alloparent is to provide care for offspring that are not your own. It is a behavior that is unimaginable for most species (few of which even care for their own offspring), rare even among relatively nurturant classes of animals like birds and mammals, and central to the existence of humankind. The vigor and promiscuity with which humans in every culture around the world alloparent stands in stark contrast to widespread misconceptions about who we are and how we should raise our children.

Humans’ survival as a species over the last 200,000 years has depended on our motivation and ability to care for one another’s children. Our babies are born as helpless and needy as it is possible for a living creature to be. The actress Angelina Jolie was once derided for describing her newborn as a “blob,” but she wasn’t far off. Human infants arrive into the world unable to provide the smallest semblance of care for themselves. Worse, over a decade will pass before a human child becomes self-sufficient—a decade during which that child requires intensive, around-the-clock feeding, cleaning, transport, protection, and training in hundreds or thousands of skills. No other species is on the hook for anywhere near the amount of care that we humans must provide our children.

Luckily, evolution never meant for us to do it alone. As the anthropologist Sarah Hrdy has described, among foraging cultures that best approximate our ancestral conditions, human babies never rely on only one person, or even two people, for care. Instead they are played with, protected, cleaned, transported, and fed (even nursed) by a wide array of relatives and other group members—as many as twenty different individuals every day, in some cases. And the more alloparenting children get, the more likely they are to survive and flourish.

You would never know any of this from reading most modern books on child development or childrearing. Attachment to and responsive care from a single primary caregiver (invariably the mother) is nearly always portrayed as the critical ingredient for a child’s optimal development. When fathers or other caregivers are mentioned at all, their impact is described as neutral at best. The implicit message is that for a baby to spend significant time apart from the mother in the care of other caregivers, like babysitters or daycare providers, is unnatural and potentially harmful.

But the opposite is more likely true. As the historian Stephanie Coontz has put it, human children “do best in societies where childrearing is considered too important to be left entirely to parents.” When children receive care from a network of loving caregivers, not only are mothers relieved of the nearly impossible burden of caring for and rearing a needy human infant alone, but their children gain the opportunity to learn from an array of supportive adults, to form bonds with them, and to learn to love and trust widely rather than narrowly.

Children are not the only beneficiaries of humans’ fulsome alloparenting capacities. Across primate species, the prevalence of alloparenting is also the single best predictor of a behavior that theories portraying human nature as motivated strictly by rational self-interest struggle to explain: altruism. Not reciprocal altruism or altruism toward close kin (which are self-interested) but costly acts of altruism for unrelated others, even strangers. This sort of altruism can seem inexplicable according to dominant accounts of altruism like reciprocity and kin selection. But it is perfectly consistent with the idea that, as alloparents sine qua non, humans are designed to be attuned to and motivated to care for a wide array of needy and vulnerable others. Altruism for one another is likely an exaptation of evolved neural mechanisms that equip us to alloparent.

Remember this if you are ever tempted to write off all humanity as a lost cause. We have our flaws, without a doubt, but we can also lay claim to being the species shaped by evolution to possess the most open hearts and the most abundant capacity for care on earth.