Facebook’s new feature has produced some mixed Reactions — namely love, haha, wow, sad and angry — thanks to input from UC Berkeley researchers.

Facebook Reactions, globally rolled out Wednesday, allow users to interact with Facebook posts through the five emoticons. Dacher Keltner — the founder and director of UC Berkeley’s Greater Good Science Center and campus psychology professor — and his team helped Facebook create the extension of the old “like” button, which remains intact.

According to Emiliana Simon-Thomas, science director of the center and collaborator on the project, the idea for Reactions had been in the making for about two years. She and Keltner were approached by Facebook because of their experience with studying human emotion.

“All of the iterative thinking and wireframing and designing and revising has been going on for that long,” Simon-Thomas said. “I think it’s a wonderfully big step in the right direction.”

Keltner’s research indicates that there are more than 20 emotions studied by scientists. Keltner worked with Matt Jones, an illustrator from Pixar, to draw more than 50 emotions that were then sent to the Facebook Reactions team.

According to an email from Alan Cowen, a campus doctoral student of psychology, Keltner’s research has helped demonstrate that a larger number of facial expressions are recognizable across cultures than previously thought — particularly awe, similar to the “wow” emoticon that Facebook has introduced.

Keltner and his team have a history of working with Facebook — in 2013, they collaborated on the site’s stickers project with a sketch artist, creating drawings consistent with Charles Darwin’s original expressions of human emotions. The stickers project eventually helped inspire Reactions, according to Simon-Thomas.

Prior to its global roll-out, Reactions had been tested in select markets since last year, according to a Facebook press release.

“I feel like (Reactions) was a way for Facebook to get around putting a dislike button,” said Sharon Chen, a campus junior.

Campus media studies lecturer Edward Timke said the new emoticons could be another tactic by Facebook to help marketers get information about users, thereby making Facebook a more attractive platform to advertisers.

Some UC Berkeley students, such as freshman Annie Tran, were critical of Facebook’s new feature, citing a potential for its misuse.

“For example, if someone posts something really serious and meaningful to them, it’s really easy for people on the Internet to misuse or abuse the purpose of (Reactions),” Tran said.

Keltner’s team will be available to Facebook to provide its scientific expertise on improving the quality of people’s experiences on the site, Simon-Thomas said.