Pleasurable Altruism
Jorge Moll and Jordan Grafman scanned the brains of volunteers as they were asked to think about a scenario involving either donating a sum of money to charity or keeping it for themselves.
When the volunteers placed the interests of others before their own, the generosity activated a primitive part of the brain that usually lights up in response to food or sex. Altruism, the experiment suggested, is basic to the brain, hard-wired and pleasurable.
Non-human animals sometimes sacrifice their own interests: One experiment found that if each time a rat is given food, its neighbor receives an electric shock, the first rat will eventually forgo eating.
Antonio R. Damasio has shown that patients with damage to the ventromedial prefrontal cortex lack the ability to feel their way to moral answers.
When confronted with moral dilemmas, the brain-damaged patients coldly came up with “end-justifies-the-means” answers. When confronted by a difficult issue — such as whether to shoot down a passenger plane hijacked by terrorists before it hits a major city — these patients appear to reach decisions without the anguish that afflicts those with normally functioning brains.
According to Joshua D. Greene, moral decision-making often involves competing brain networks vying for supremacy.
In one 2004 brain-imaging experiment, Greene asked volunteers to imagine that they were hiding in a cellar of a village as enemy soldiers came looking to kill all the inhabitants. If a baby was crying in the cellar was it right to smother the child to keep the soldiers from discovering the cellar and killing everyone?
The reason people are slow to answer such an awful question is that emotion-linked circuits automatically signaling that killing a baby is wrong clash with areas of the brain that involve cooler aspects of cognition. One brain region activated when people process such difficult choices is the inferior parietal lobe, which has been shown to be active in more impersonal decision-making. This part of the brain was “arguing” with brain networks that reacted with visceral horror.
Marc Hauser has found that people all over the world process moral questions in the same way. Different cultures build on that framework in much the way children in different cultures learn different languages using the same neural machinery.
“If It Feels Good to Be Good, It Might Be Only Natural,” by Shankar Vedantam