[An inspiring passage from Adam Grant's book, Give and Take.]

For nearly forty years, two of the world's most distinguished psychologists have locked horns over whether the decision to give can be purely altruistic, or whether it's always ultimately selfish. Rather than debate philosophy, each has come to battle wielding a deadlier weapon: the psychological experiment. The defendant of pure altruism is C. Daniel Batson, who believes that we engage in truly selfless giving when we feel empathy for another person in need. The greater the need, and the stronger our attachment to the person experiencing it, the more we empathize. When we empathize with a person, we focus our energy and attention on helping him or her -- not because it will make us feel good but because we genuinely care. Batson believes that although some people feel empathy more intensely and frequently than others, virtually all humans have the capacity for empathy -- even the most disagreeable of takers.

As Adam Smith put it centuries ago: "the emotion which we feel for the misery of others . . . is by no means confined to the virtuous and humane, though they perhaps may feel it with the most exquisite sensibility. The greatest ruffian, the most hardened violator of the laws of society, is not altogether without it." The devil's advocate is Robert Cialdini, who argues that there's no such thing as pure altruism. He believes that human beings are frequently generous, giving, and caring. But he doesn't think these behaviors are entirely altruistic in origin. He believes that when others hurt, we hurt—and this motivates us to help. Cialdini's first challenge to Batson's claims was that when empathy leads us to help, it's not because our ultimate goal is to benefit the other person. He proposed that when others are in need, we feel distressed, sad, or guilty. To reduce our own negative feelings, we help. Cialdini accumulated an impressive body of studies suggesting that when people feel distressed, guilty, or sad toward another person in need, they help.

Batson's rebuttal: it's true that people sometimes help to reduce negative feelings, but this isn't the only reason. And negative feelings don't always lead to helping. When we feel distressed, sad, or guilty, our ultimate goal is to reduce these negative feelings. In some cases, helping is the strategy that we choose. But in many cases, we can reduce our negative feelings in other ways, such as distracting our-selves or escaping the situation altogether. Batson figured out a clever way to tease apart whether empathy drives us to help because we want to reduce another person's distress or our own distress. If the goal is to reduce our own distress, we should choose whatever course of action makes us feel better. If the goal is to reduce another person's distress, we should help even when it's costly and other courses of action would make us feel good. In one experiment, Batson and colleagues gave people a choice: watch a woman receive electric shocks or leave the experiment to avoid the distress. Not surprisingly, 75 percent left. But when they felt empathy for the woman, only 14 percent left; the other 86 percent stayed and offered to take the shocks in her place. And of the people who stayed to help, the ones who empathized the most strongly were willing to endure four times as many shocks as those who felt less empathy.

Batson and colleagues demonstrated this pattern in more than half a dozen experiments. Even when people can reduce their negative feelings by escaping the situation, if they're feeling empathy, they stay and help anyway, at a personal cost of time and pain. On the basis of this evidence, Batson concluded that reducing bad feelings is not the only reason people help, and a comprehensive analysis of eighty-five different studies backed him up. But Cialdini, one of the greatest social thinkers of our time, wasn't done yet. He acknowledged that empathy can drive helping. Feelings of concern and compassion certainly motivate us to act for the benefit of others at a personal cost. But he wasn't convinced that this reflects pure altruism. He argued that when we empathize with a victim in need, we become so emotionally attached that we experience a sense of oneness with the victim. We merge the victim into our sense of self. We see more of ourselves in the victim. And this is why we help: we're really helping ourselves. Quoting Adam Smith again, "By the imagination we place ourselves in his situation, we conceive ourselves enduring all the same torments, we enter as it were into his body,. and become in some measure the same person with him, and thence form some idea of his sensations, and even feel something."

Cialdini and colleagues conducted numerous experiments supporting this idea. Empathy leads to a sense of oneness, or self-other overlap, and this leads to greater helping. Batson's team came back with another rebuttal: that is altruism. If we empathize with other people to the point of merging our own identities with theirs, we care about them as much as we care about ourselves. Because we no longer place our interests above theirs, helping them is purely altruistic.

Stalemate. Both camps agree that empathy leads to helping. Both camps agree that a sense of oneness is a key reason why.  But they fundamentally differ about whether oneness is selfish or altruist— believe there’s a middle ground here, and it's one that Deron Beal discovered early on. When he started Freecycle, he wanted to keep used goods out of landfills by giving them away to people who wanted them. But he also had some personal interests at stake. In his recycling pro-gram, he had a warehouse full of stuff he couldn't use or recycle, and his boss wanted the warehouse emptied. In addition, Beal was hoping to get rid of an old mattress that he owned. None of his friends needed it, and it was too big to throw away. To dump it, he would need to borrow a truck and drive the mattress to a landfill, where he would be charged for disposal. Beal realized it would be easier and cheaper if he could just give it away to someone on Freecycle.

This is why many takers and matchers started giving on Freecycle It's an efficient way to get rid of things they don't want and probably can't sell on Craigslist. But soon, Beal knows from personal experience, people who initially give things away for selfish reasons begin to care about the people they're helping. When the recipient arranged to pick up his mattress, Beal was thrilled. "I thought I was getting away with giving a mattress away, that I was the one benefiting," he says. "But when the person showed up at my door and thanked me, I felt good. It was only partially a selfish act: I was helping someone else in a way that made me happy. I felt so darn good about it that I started giving away other items." After a decade of research, I've come to the conclusion that Beal's experience is the norm rather than the exception. Oneness is otherish. Most of the time that we give, it's based on a cocktail of mixed motives to benefit others and ourselves. Takers and matchers may be most likely to give when they feel they can advance others' interests and their own at the same time. As the primatologist Frans de Waal writes in The Age of Empathy, "The selfish/unselfish divide may be a red herring. Why try to extract the self from the other, or the other from the self, if the merging of the two is the secret behind our cooperative nature?;)