Jeannette Haviland-Jones, Rutgers University psychology professor and lead researcher on the study, admitted she was initially cynical about the project, assuming the study would find people simply like flowers because they associate them with happy events.

“I thought that it wasn’t really a psychological phenomenon,” she said. “But it turned out that nobody could be more wrong than I was.”

Flowers just make you smile

During a series of exercises used for a controlled study, Haviland-Jones and her students delivered several gift packages, one being a bouquet of flowers, to a wide range of women.

“One hundred and fifty subjects later, data showed 100 percent of them had a Duchenne smile,” Haviland-Jones said. The Duchenne smile, often called a “genuine” smile, includes crinkles by the eye. “One of the few things I know that gives a 100 percent reaction is if you drop a snake on somebody, which incites 100 percent fear in people. So I thought this was amazing.”

A similar study was conducted on men. What this round of data showed, Haviland-Jones said, is that “it’s every bit as true for men as it is for women.”