Your giving brain: Are humans 'hardwired' for generosity?

Our brains nudge us toward altruism, scientists have discovered.

As the year winds to a close, gifts and giving are foremost in many people's minds. And now, two new neuroscience studies suggest that our brains prompt us to act more like Santa than Scrooge.

In one study, researchers scanned participants' brains to identify connections between generous behavior and brain activity. In the other, scientists dampened activity in areas of the brain associated with impulse control, to see if that would alter a person's empathetic actions.

The findings from both studies led the researchers to conclude that human behavior is guided more by empathy and generosity than by selfishness.

In addition, the findings suggest a path toward treating people with conditions that lower their ability to understand others: Someday, people whose social cognition is impaired could be helped by treatments that regulate the neural pathways that enhance or restrict their empathetic feelings, said Dr. Marco Iacoboni, a co-author of both studies and a professor of psychiatry at the David Geffen School of Medicine at the University of California at Los Angeles.

Seeing brain activity

In the first study, the neuroscientists used imaging to look at brain activity while study participants performed an activity that tested their generosity. First, the scientists imaged participants' brains as they watched footage of a hand being jabbed with a pin, and then as they mimicked facial expressions shown to them in photos. This allowed the researchers to note which of the participants showed greater activity in brain regions associated with recognizing pain in others .

Next, the participants were given money, which they could distribute however they chose among people represented by profiles on a computer.

The researchers expected to "see correlations between the amount of money subjects are willing to share, and the response of their brains in the scanner while they're watching people in pain — and we got that," Iacoboni explained.

The scientists found that the scans of the stingiest participants showed the most activity in the prefrontal cortex, which regulates impulses.

Meanwhile, the most generous subjects showed heightened brain activity in regions linked to recognizing pain and emotion, and to mirroring others' behavior, according to the study, which was published online Feb. 1 in the journal Human Brain Mapping .

"It’s almost like these areas of the brain behave according to a neural Golden Rule," study co-author Leonardo Christov-Moore, a neuroscientist at the University of California in Los Angeles, said in a statement. "The more we tend to vicariously experience the states of others, the more we appear to be inclined to treat them as we would ourselves."

Disabling impulse control

In the second study, the researchers used brain stimulation to look at the question of whether human nature is essentially generous, with selfishness only emerging through civilization and learned behavior, Iacoboni told Live Science. Electrical stimulation can restrict or heighten the activity in specific brain areas.

"We can knock out an area in the brain for a while and see what happens when it goes offline, or we can increase activity in a brain region to see if things change," Iacoboni told Live Science.

In the study, the scientists temporarily disabled parts of the brain's prefrontal cortex that they suspected normally restrict people's generosity. In other words, they expected that "turning off" parts of the prefrontal cortex should mean that the subjects would give away more money, Iacoboni said.

The study participants experienced 40 seconds of theta-burst Transcranial Magnetic Stimulation (TMS), in which a magnetic coil placed near the head sends electrical currents to specific brain regions.

In this case, the scientists targeted two areas in the prefrontal cortex , temporarily removing their ability to block impulses. Then, as in the first study, the participants were given money to distribute among a group of people via computer profiles.

The results showed that temporarily shutting down the prefrontal cortex did wonders for people's generosity — they were about 50 percent more generous with their money than participants in the control group, according to the study published online March 21 in the journal Social Neuroscience .

"Knocking out these areas appears to free your ability to feel for others," Christov-Moore said in a statement. "The cornerstone of social cognition is empathy. So, in principle, by increasing empathy one could increase social cognition in people. You could modulate control areas for social behavior. That would be a big deal," Iacoboni said.

Original article on Live Science .