Scientists study generosity

People can be generous to strangers — say giving money to a homeless person — but for some it comes easier than for others.

Some people are using all their self-control to be a good Samaritan, when they really just want to be a Scrooge, according to research from a California scientist.

Cendri Hutcherson, a researcher from the California Institute of Technology in Pasadena, Calif., presented the results of a study she led on generosity, as part of the Neuroscience 2012 conference, held in October in New Orleans.

“My research tries to understand why people are generous and why some people are more generous than others,” Hutcherson told reporters at one of several press conferences offered at the event.

The Neuroscience gathering, held this year at New Orleans’ Ernest N. Morial Convention Center, is described in its literature as “the world’s largest source of emerging news about brain science and health.”

It’s the annual meeting of the Society for Neuroscience, an organization of more than 42,000 basic scientists and clinicians who study the brain and nervous system.

Hutcherson spoke as one of four researchers at a press conference called “The Social Brain.”

“We see people behaving generously all the time, with money or donating their time, but we don’t know what motivates people to do that,” she said in a phone interview a few days after the presentation.

“Do they really like helping people? Or mom told them they’d be a bad person if they didn’t,” said Hutcherson, who’s a postdoctoral scholar in neuroeconomics.

“Generous behavior makes society function,” she said.

She wanted to learn more about it.

For her study, 50 people, ages 18 to 30, were recruited to take part in a roughly 45-minute exercise in which they lay in a type of MRI (magnetic resonance imaging) scanner and, watching a computer screen above their head, made choices about money for themselves — and an anonymous partner.

Those anonymous partners were 50 other, real people who got to spend their part of the study just hanging out, Hutcherson explained.

Each of the partners walked away from the experiment with some cash, she said.

On the computer screen, the person in the MRI machine would see dollar amounts posted, two at a time, with one intended for themselves and one for their anonymous partner.

Sometimes there was great disparity between the two amounts, sometimes they were close, Hutcherson said.

For example, a person could choose to get $90 for themselves and just have their partner get $5 by saying “yes” to that particular arrangement.

If they didn’t like the choice they saw and said “no,” both parties got $50.

These choices came up 180 times, and at the end of the trial one choice for each subject was chosen randomly to go into the research, she said.

Using a type of MRI that uses functional magnetic resonance imaging that shows blood flow, reflecting brain activity, here’s what the researchers found:

More generous people use a part of their brain to make their decision about giving, called the temporoparietal junction “an area typically implicated in empathy,” Hutcherson said.

Less generous people use a part of their brain called the prefrontal cortex, the area of self control.

“It’s as if more selfish people have to work hard to force themselves to do the right thing,” Hutcherson said.

The empathy mechanism “seems to be a little more effective in producing generosity,” Hutcherson said, but both self-control and empathy can lead to generosity.

Researchers also watched a part of the brain called the ventromedial prefrontal cortex, in which activity is high when someone gets something they want and low when they don’t.

“When we looked at the most generous folks, their brain responded to a reversal of a generous choice as if they were genuinely disappointed,” Hutcherson said.

Can people, then, not help whether they’re naturally generous or not?

Hutcherson said she doesn’t believe that’s the way it works.

“I think it’s probably not biological. I imagine that this is something people can change. It may depend on context or depend on people’s moods,” she said.

“I wouldn’t be ready to say it’s hard-wired,” Hutcherson said.

“We’re trying to figure out how this can be useful” through further research, she said. This initial study was supported with funds from the National Science Foundation and the California-based Gordon and Betty Moore Foundation, which is devoted to “positive outcomes for future generations.”

“When (people) use the empathy-related impulse, that correlates with people being more generous,” Hutcherson said.

She wonders if people could be educated to think more about others but said, “I think the jury’s out on that.”

Hutcherson gave a little laugh when asked if any particular organization had contacted her about how the research could be used to get people to be more generous benefactors.

“I think that, like lots of things, knowledge like this” can be used for good or “it can also be exploited,” she said.

“No one’s talked to us” about any particular use for the findings, she added.

Hutcherson was a bit surprised by the findings of her study.

“Going into it, we thought that self-controlled (people) would be more generous,” she said.

“We’ve seen in other paradigms that they are more likely to make healthy choices,” Hutcherson said.

But, as it turned out, if someone’s using self control to be generous “that means it’s harder” to be so, she said.

“We were sort of expecting that people who were good at resisting temptations would be good at being generous,” Hutcherson said.