Is Human Nature Fundamentally Selfish or Altruistic? Did selfishness - or sharing - drive human evolution? Evolutionary theorists have traditionally focused on competition and the ruthlessness of natural selection, but often they have failed to consider a critical fact: that humans could not have survived in nature without the charity and social reciprocity of a group. Last week on Slate, evolutionary anthropologist Eric Michael Johnson explored the question against the backdrop of two cultural events in 1957 - the consequences of the rogue, selfish activities of a pygmy hunter in a Congo forest, who used the group's collective hunting efforts to benefit only himself, and in New York City, the publication of Ayn Rand's novel Atlas Shrugged, whose protagonist champions the author's notion that human nature is fundamentally selfish and that each man "exists for his own sake, and the achievement of his own happiness is his highest moral purpose." Atlas Shrugged counts many politicians as admirers, perhaps most notably Republican vice presidential candidate, Paul Ryan, who cites the book as one of his main inspirations for entering politics and is known to give Rand's books frequently to his interns. MORE: "Paradise Built in Hell:" How Disaster Brings Out the Best in People So, does Rand's theory comport with current evolutionary theory? The data is not exactly kind to her position. For example, Johnson describes an anthropologist's account of the pygmy tribesman, Cephu, in the Congo who lived by the Randian ideal that selfishness is the highest morality. Cephu was part of the Mbuti tribe for whom "hunts were collective efforts in which each hunter's success belonged to everybody else," Johnson writes, detailing how the tribe "employed long nets of twined liana bark to catch their prey, sometimes stretching the nets for 300 feet. Once the nets were hung, women and children began shouting, yelling, and beating the ground to frighten animals toward the trap. It was a group effort, for most: But one man, a rugged individualist named Cephu, had other ideas. When no one was looking, Cephu slipped away to set up his own net in front of the others. Soon caught in this blatant attempt to steal meat, Cephu was brought in front of the whole tribe: At an impromptu trial, Cephu defended himself with arguments for individual initiative and personal responsibility. "He felt he deserved a better place in the line of nets," [the anthropologist Colin] Turnbull wrote. After all, was he not an important man, a chief, in fact, of his own band? But if that were the case, replied a respected member of the camp, Cephu should leave and never return. The Mbuti have no chiefs, they are a society of equals in which redistribution governs everyone's livelihood. The rest of the camp sat in silent agreement. Faced with banishment, a punishment nearly equivalent to a death sentence, Cephu relented. He apologized, handed over his meat to the tribe and then, essentially, was sent to bed without dinner. As Johnson explains, selfishness is considered far from a virtue in such tribal groups, which still live in ways similar to our hunter-gatherer ancestors. Indeed, every such group ever studied has been found to idealize altruism and punish selfishness, in everything from their mythologies to their mating practices. (MORE: How Economic Inequality Is (Literally) Making Us Sick) Although Rand accepted that early human life was a collective effort, she failed to realize how this shaped our brains. In most societies, for example, a man like Cephu would be seen as the opposite of a good catch for a woman wanting a partner. A good mate - and one whose genes were likely selected for and passed on in our earliest evolutionary history - would have been a cooperative hunter, one who didn't put his own goals ahead of those of the tribe. He would have been altruistic in battle too, particularly when warring with other groups. A selfish soldier, after all, is known as a coward, not a hero. The evidence for altruism as a critical part of human nature isn't limited to anthropology. Studies of 18-month-old toddlers show that they will almost always try to help an adult who is visibly struggling with a task, without being asked to do so: if the adult is reaching for something, the toddler will try to hand it to them, or if they see an adult drop something accidentally, they will pick it up. However, if the same adult forcefully throws something to the ground, toddlers won't try to retrieve it: they understand that the action was deliberate and that the object is unwanted. These very young children will even assist (or refrain from helping) with a book-stacking task depending on what they perceive to be the adult's intention. If the adult clumsily knocks the last book off the top of the stack, the toddler will try to put it back; if the adult deliberately takes the last book off, however, toddlers won't intervene. Even before kids are taught to chip in - perhaps especially before they are told it's an obligation - children are less selfish than often presumed. Another study found that 3- to 5-year-olds tend to give a greater share of a reward (stickers, in this case) to a partner who has done more work on a task - again, without being asked - even if it means they get to keep less for themselves. And those cries of "That's not fair!" that plague sibling relationships: they're not only selfish; they reflect children's apparently innate desire for equity. MORE: The Upside of Gossip: Social and Psychological Benefits Fundamental tendencies toward altruism aren't only seen in children, either. Worldwide, the aftermath of natural disasters are typically characterized by heroism and a sharing of resources - within the affected community and in others farther way - not selfish panics. During the terrorist attacks of 9/11, for example, there were no accounts of people being trampled rushing out of the World Trade Center towers; rather, those who needed assistance descending were cared for, and calm mainly prevailed. The same occurred after the earthquake, tsunami and nuclear meltdown in Japan in 2011. The cases in which people stampede or look out only for themselves tend to be rare and involve very specific circumstances that mitigate against helpfulness. Moreover, our stress systems themselves seem to be designed to connect us to others. They calm down when we are feeling close to people we care about - whether related to us or not - and spike during isolation and loneliness. Even short periods of solitary confinement can derange the mind and damage the body because of the stress they create. And having no social support can be as destructive to health as cigarette smoking. Of course, none of this is to say that humans are never selfish or that we don't have a grasping, greedy part of our nature. But to claim, as Rand does, that "altruistic morality" is a "disease" is to misrepresent reality. Share the love and read the rest of Johnson's fascinating feature here. MORE: An Evolutionary Explanation for Altruism: Girls Find It Sexy