MRI scans like this one can detect which areas receive oxygen (and are thus active). These scans have shed light on our sense of altruism.

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Altruism, a Biological Imperative?

Whenever researchers use magnetic resonance imaging (MRI) to observe test subjects as they perform a particular task, it seems that some new secret of our brains is unlocked. Altruism is no exception.

One 2006 study focused on anonymous charitable donations, which are pretty specific altruistic acts: The giver receives no tangible reward, he or she gives away hard-earned money to benefit a total stranger, and he or she cannot expect any thanks, since the donation is anonymous. It’s altruism at its purest.

But researchers found that the subjects that contributed to charities did receive some benefit: the warm-fuzzies. In the study, 19 female volunteers had a choice: They could keep money or donate it to charities of differing ideologies. The researchers found that giving money activated the same reward center in the brain that was activated when the participants received money [source: Moll, et al.].

Another study the following year also used MRI to study the phenomenon of altruism. The researchers in this study, however, concluded that people aren’t altruistic because they receive a good feeling when they perform a selfless act, but because they perceive others are like them. The researchers found that the area of the brain that is activated when people analyze social bonds indicates that before we do something nice for someone else, we might first examine whether or not that person would reciprocate if the shoe were on the other foot [source: Duke University]. If we think someone else would act altruistically toward us, the study suggests, we would be more likely to act altruistically toward that person.

But why would we possess such a trait?

According to evolutionary theory, behaviors develop when they help living things to survive. Animals feel discomfort when they're hungry, signaling it’s time to eat. A plant might shed its leaves in the fall to create a protective mulch barrier for the winter. Flora and fauna survive by looking out for themselves. By this logic, altruism shouldn’t even exist.

“For any behavior to survive natural selection, it needs to help an animal or its genetic material,” writes author Sophie F. Dingfelder [source: APA]. So the idea that we have a natural imperative to help others at our own detriment flies in the face of evolutionary theory. Altruism must serve some unseen purpose that favors our survival. So what is it?

One of the more commonly cited examples of altruism is a mother risking her own life to save her child’s. “To an evolutionary theorist this is an obvious case of kin selection,” writes the University of Michigan’s Daniel J. Kruger [source: Kruger]. The belief that altruism is kinship-based, meaning our blood relatives are generally the beneficiaries of our altruism, lends itself to an extension that altruism exists to protect the genetic line.

Author Richard Dawkins, in his book, “The Selfish Gene,” considers humans as mere “vehicles” for a genetic line [source: Swerdlow]. Since we pass on half of our genes, when we protect our offspring or blood relatives at the risk of our own lives, our altruistic behavior is merely our genes acting to protect their lineage.

There are other interpretations of altruism within the sciences, however. One explanation posits that altruism lies not within some genetic urge, but outside ourselves. Read about the social implications of altruism on the next page.