Researchers made a new breakthrough that could one day lead to a pill that makes one more compassionate.

The drug would change the neurochemical balance in the prefrontal cortex, which would make the patient more likely to engage in prosocial behaviors, such as giving spare change to someone in need, the University of California - Berkeley reported. The findings could also provide insight into the connection between dopamine-brain mechanisms and mental illnesses such as schizophrenia and addiction.

"Our study shows how studying basic scientific questions about human nature can, in fact, provide important insights into diagnosis and treatment of social dysfunctions," said Ming Hsu, a co-principal investigator and assistant professor at UC Berkeley's Haas School of Business.

To make their findings, researchers gave 35 study participants either a pill containing tolcapone, which prolongs the effects of dopamine or a placebo. The researchers then conducted an economic game in which the participants were asked to divide money between themselves and an anonymous person. After receiving tolcapon, the study subjects proved to divide the money in a fairer manner than when they were given a placebo. Computational modeling also revealed tolcapone's influence on social behavior.

"We typically think of fair-mindedness as a stable characteristic, part of one's personality," Hsu said. "Our study doesn't reject this notion, but it does show how that trait can be systematically affected by targeting specific neurochemical pathways in the human brain."

The researchers connected their new research with previous studies on the effect of dopamine, and believe collectively this research will help them determine exactly how prosocial behaviors are spurred by the brain.

"We have taken an important step toward learning how our aversion to inequity is influenced by our brain chemistry," said the study's first author, Ignacio Sáez, a postdoctoral researcher at the Haas School of Business. "Studies in the past decade have shed light on the neural circuits that govern how we behave in social situations. What we show here is one brain 'switch' we can affect."

The findings were published in a recent edition of the journal Current Biology.