Immersion in a group to the point that one loses a sense of self-awareness and feels lessened responsibility for one’s actions.
Example: Groups of excited, rioting sports fans celebrating a big win can end up commiting acts they would never do alone, such as vandalism or arson.
Grinnell, R. (2008). Deindividuation. Psych Central. Retrieved on May 29, 2015, from http://psychcentral.com/encyclopedia/2008/deindividuation/