Four scholars examined discrimination and hate through the lens of social psychology — the study of interpersonal behavior and individual behavior in group contexts — during a panel discussion Tuesday night.

The panel was the second in a series of four talks planned by administrators last semester after inflammatory graffiti appeared on campus walls in November. Four Yale psychology professors, moderated by Yale College Dean Peter Salovey, spoke for an hour and a half on all forms of prejudice in an attempt to illuminate its underlying psychological causes.

The panelists said psychology is behind much hateful behavior in today’s society.

“We all have these unconscious biases that can give us the potential to behave in racist ways,” said panelist John Dovidio, a psychology professor who specializes in social power relations. “One of the first things we do in human perception is categorize people.”

The panel also included psychology professors Marianne LaFrance and Valerie Purdie-Vaughns, as well as Betsy Paluck ’00 GRD ’07, a scholar from Harvard’s Weatherhead Center of International Affairs.

LaFrance discussed the role of humor in perpetuating discrimination, particularly in sexist and homophobic contexts. “Hate speech,” she explained, “takes a variety of forms.” Since it is not illegal, people often fail to object to it — allowing it to become habituated to its attitudes. This can leave individuals so numbed that normal coping methods are not effective in situations where a legitimate danger is posed, she said

Purdie-Vaughns introduced a topic that sparked vigorous response from the audience during the question-and-answer session. Discrimination in the classroom may reduce the academic performance of those targeted, she said. As example of a phenomenon she called “stereotype threat,” she referenced a study in which men and women were given a math test to complete. Women performed considerably worse when they were told the exam would measure their “mathematical intellect,”playing on the stereotype that women underperform men in the sciences.

Paluck spoke last about research she had done in Rwanda and the role of media and narrative both as tools of hate and to promote inter-group harmony. After observing the crucial role of propagandist radio in the origin of Rwanda’s genocide, she worked to create a radio soap opera designed to teach listeners how to avoid and deflect discriminatory situations.

A point of some contention among panelists and audience members was a suggestion from one student in the audience to require students to take a class examining diversity and ethnicity.

LaFrance said such a requirement would exacerbate racial tensions.

“A mandatory course is the death nail for sensitivity,” she said.

Paluck agreed, noting that her research indicated that people need to be inspired to revise social norms, not subjected to reeducation.

But Purdie-Vaughns took a somewhat different stance. A specific, well thought-out program, she asserted, could have a positive impact, particularly in terms of redirecting social norms.

The sentiments among students interviewed were equally mixed. Robert Klipper ’11 said students would not be receptive to a requirement.

“People are averse to things that are forced on them,” he said.

Two more panels, exploring the politics of hate and the sociology of hate, will take place later this semester.