Coffee with Coworkers helps productivity
News Release

Coffee with Coworkers Is More Productive and Feels Better, UC Davis Study Finds
First research on the effects of caffeine on group work

It’s well known that a cup of joe can make you feel more awake, alert and may improve your acuity. Now, a new study from UC Davis on the effects of caffeine from coffee confirms that drinking moderate amounts can enhance your performance working in teams and boost your perceptions of others in group activities.

At least four decades of research have been dedicated to coffee. Studies have so thoroughly covered this topic that they’ve gained a reputation for contradicting each other and for even leading to court-ordered advisories. Yet historical research has focused on the effects on individuals, not groups.

“We see coffee being served in many meetings but found very little research on how coffee might affect group dynamics,” Adjunct Assistant Professor Vasu Unnava said in an interview with PsyPost. She co-authored the study with her husband, Rao Unnava, dean of the UC Davis Graduate School of Management, 


The Unnavas and their research partner, Amit Singh, a graduate student at Ohio State University, designed experiments involving about 70 undergraduates students who were already participating in a tasting of a new brand of coffee scheduled for launch in the United States.

The researchers developed a point system for coding statements from the group conversations into usable data for tabulating the results. This led the observers to note that caffeinated volunteers delivered a higher quality of arguments when working through simple group activities, and they had more of them.

Their findings showed that caffeine was found to increase a group’s focus and encourage each person to participate more in discussions. Of greater interest, those who consumed caffeinated coffee before a group task evaluated their own and the group’s performances more positively than those who did not consume coffee.

The Unnavas paper, “Coffee with Co-workers: Role of Caffeine on Evaluations of the Self and Others in Group Settings,” has been published in the Journal of Psychopharmacology. It’s the first research study from management school professors to be published in the international scientific journal.

“As business school faculty,” says Rao Unnava, “we were very excited to get it accepted in a journal of a different discipline.”

“Is it the caffeine in the coffee or the simple act of consuming coffee together that made people feel positive?”


One question about the act of drinking coffee itself still nagged the researchers.

“Is it the caffeine in the coffee or the simple act of consuming coffee together that made people feel positive?” wondered Vasu Unnava.

She refined the experiment so that all the participants instead enjoyed a cup of Joe together. The effects were the same.

“They are very intriguing results,” she says. “There is a strong difference between the number of arguments and a strong difference between the quality of arguments.”

Rather than proclaiming caffeine as the ultimate catalyst for better group work, the researchers pointed to the increased level of alertness as being the mechanism behind their findings.

“If you look at where coffee’s being consumed, a significant amount happens in group settings… You don’t ask them if they want juice!”

Vasu Unnava pointed out to PsyPost that the study does have its caveats: 

“Our coffee drinkers came to the study after staying away from coffee for a few hours,” she said. “So, we do not know if the coffee they consumed in the study increased their alertness or it is the decreased alertness in those who consumed decaffeinated coffee that caused the effects reported in the study. Second, we used a topic that the participants generally agreed on. What the results might be if there is disagreement is an interesting issue to study further. Finally, we used only one type of task—group discussion. How coffee may affect people’s performance in other kinds of tasks (e.g., group problem solving, group physical work) is not known.”


The new study adds to the body of research being done at the new UC Davis Coffee Center, the first multidisciplinary university research center to address the challenges and needs of the coffee industry through a holistic approach to coffee science and education.

“The Coffee Center is poised to do for coffee what UC Davis did for wine and beer: to become the leading source of scientific expertise in the study of coffee,” says Professor William Ristenpart, director of the center.

According to David Kyle, an associate professor in sociology affiliated with the Coffee Center, the study by Rao and Vasu Unnava gives proof to what has long been a mainstay of North American coffee culture. 

“For centuries, coffee rituals were as much about the gathering of friends and not just the drink,” he said in a California Aggie article on the study. “For example, soon after arrival in London in the 1600s, there were already 2,000 coffee shops in 1700. They were known as penny universities because for a penny a cup you could engage people from all walks of life in sustained discussion about any topic. I’m happy to see that UC Davis researchers are turning to the social dimensions of coffee consumption and culture.”