Being good to other people isn't just something we choose to do. New research shows that our brains may be wired to be generous, and it's thanks to our ability to imagine ourselves in the place of others.
Leonardo Christov-Moore and Marco Iacoboni, of UCLA, carried out two clever experiments to see if we are "hardwired for altruism." One showed participants a video of a pin spiking a human hand (with a control image of a hand being jabbed with a Q-tip), and the other tested participants to see how much money they were willing to share with people. During the experiments, the brains of the participants were monitored by an fMRI brain-scanning machine.
In our brains, the amygdala, somatosensory cortex, and anterior insula are associated with—among other things—pain, emotion, and also with emulating others. They "contribute to our evaluations of others’ beliefs, internal states, and intentions," say the researchers.
To test the connection between empathy and generosity, they first measured the brains of 20 participants while they watched the hand being spiked. Then, in a second test, they evaluated generosity by inviting participants to play the "dictator game," a well-known game with one simple rule—participants decide how to split an endowment (in this case, $10) between themselves and another person. In the experiment, the other people were represented by photographs depicting high- and low-income individuals. Further, the subjects were told (truthfully) that at least some of these people would receive a portion of the cash rewards.
By manipulating and/or measuring parts of the brain, Christov-Moore and Iacoboni found that those who showed the most empathy for the people getting jabbed with a needle were also more likely to give generously in the second test.
"Participants with the most activity in the prefrontal cortex proved to be the stingiest," says UCLA's Meg Sullivan, "giving away an average of only $1 to $3 per round." The prefrontal cortext is "responsible for regulating behavior and controlling impulses."
But those who were found to be the most empathic, that is, those who showed the most activity in the parts of the brain associated with perceiving pain and emotion, and with imitating others, gave away the most—around 75% of the money.
A follow-up study actually knocked out parts of the brain temporarily, using a technique called theta-burst transcranial magnetic stimulation. Depending on which part of the brain was suppressed, the subjects changed their giving behavior. By dampening the dorsomedial prefrontal cortex, participants got more generous, but when the dorsolateral prefrontal cortex was suppressed, they "tended to be more generous to recipients with higher incomes."
"Normally, participants would have been expected to give according to need, but with that area of the brain dampened, they temporarily lost the ability for social judgments to affect their behavior," Christov-Moore told the UCLA newsroom. "By dampening this area, we believe we laid bare how altruistic each study participant naturally was.
Christov-Moore and Iacoboni conclude that humans use the same part of the brain for both kinds of tasks, so that a person who feels strong empathy for other people will also be predisposed to generosity when "making conscious decisions about the welfare of others." And while the study doesn't offer any theories as to why we might be wired this way, it does point out that specific parts of the brain could be targeted to help treat people with mental conditions.
The knowledge can also be useful for us. Having read about this study, we can now try to be more empathetic—and hope that makes us more generous as well.