Study Reveals Role of Dopamine and Serotonin in Social Behavior, Decision-Making

February 26, 2024

Research Shows Human Behavior Guided by Fast Changes in Dopamine LevelsA new international study is shedding light on how certain brain chemicals influence social behavior.

The study, which published online today in Nature Human Behavior, provides evidence that dopamine and serotonin play distinct roles in processing social context and value signals during decision-making. 

Dopamine and serotonin are neurotransmitters that affect how people think, feel and act. These chemical messengers are used by the nervous system to regulate functions and processes in the body. 

In the study, four patients receiving deep brain stimulation surgery for Parkinson’s disease were immersed in the take-it-or-leave-it ultimatum game, a scenario where they had to accept or reject varying monetary offers up to $20 from both human and computer players. To detect and record serotonin and dopamine released from neurons, carbon-fiber microelectrodes were inserted deep into the brain.

The researchers found that study participants were more likely to accept offers from computers while rejecting identical offers from human players.

The idea that people make decisions based on fairness is not a new one in neural economic games. But now, for the first time, researchers show the social context may be built on the dynamic interactions of dopamine and serotonin.

When people make decisions, dopamine seems to closely follow and react to whether the current offer is better or worse than the previous one, as if it were a continuous tracking system. Serotonin, meanwhile, appears to focus only on the current value of the specific offer at hand, suggesting a more case-by-case evaluation. This fast dance happens against a slower backdrop, where dopamine is overall higher when people play a human being – in other words, when fairness comes into play. Together, these signals contribute to our brain’s overall assessment of value during social interactions.

The research team included Kenneth Kishida, Ph.D., a co-author of the study and an associate professor of translational neuroscience and neurosurgery at Wake Forest University School of Medicine; Read Montague, Ph.D., professor of the Fralin Biomedical Research Institute at Virginia Tech Carilion and the senior author; and shared first authors Dan Bang, associate professor of clinical medicine and Lundbeck Foundation Fellow at Aarhus University in Denmark; and Seth Batten, a senior research associate in Montague’s lab.

For more than 15 years, Kishida has studied the human brain and how these neurotransmitters impact decision-making. 

“We are particularly interested in how these processes are altered in brain disorders such as Parkinson’s disease, epilepsy, depression or substance abuse disorder,” Kishida said. “This work could potentially result in advancements in medications or treatments.”

Read the full release from Virginia Tech.

Media Contact: Myra Wright,