A phenomenon wherein the decisions and opinions of people in a group setting become more extreme than their actual, privately held beliefs.
Example: After a discussion about racism, members of the group who are racist will defend their attitudes far more strongly than they would have beforehand.
Grinnell, R. (2009). Group Polarization. Psych Central. Retrieved on May 22, 2015, from http://psychcentral.com/encyclopedia/2009/group-polarization/