Earlier this month, social psychologist Leonard Berkowitz passed away. You can read his obituary here. It is practically impossible to be an aggression researcher and not encounter his influence. Much of his work focused on media violence and cognitive cues on aggressive behavior. He also was well known for his efforts to advance theory and research on the relationship between frustration and aggression. His own theoretical model, the Cognitive Neoassociation Model, shared quite a bit in common with the theoretical model that has guided much of my own research. Berkowitz was a solid methodologist, and one who wrote quite extensively in defense of the lab experiment - a research approach that was at one point under attack (look up the "crisis" in social psychology). When I was initially admitted to the University of Missouri's Social Psychology doctoral program, my summer reading list included work by Berkowitz, and I was strongly encouraged to get a hold of a copy of his then-current textbook on aggression. One of Mizzou's Social Psychology faculty members, Russ Geen, was in fact one of Berkowitz's students, and Berkowitz was an informal mentor to one of my friends and a current collaborator, Brad Bushman (one of Russ Geen's students).
Leonard Berkowitz continued to publish long after he retired, and although I did not know him particularly well, we did share some correspondence periodically with regard to the weapons effect, a phenomenon that he is credited (along with Anthony LePage) with discovering. His work will undoubtedly continue to be influential for many decades to come. Any aggression researcher studying the weapons effect will be citing his famous article that established the phenomenon. Many of us studying media violence or provocation effects will be citing Berkowitz's key research articles or his theoretical work for the foreseeable future. He has left an impressive legacy. That said, he will be tremendously missed in my particular corner of social psychology.