Lee David Ross (August 25, 1942 – May 14, 2021) was a Canadian-American professor who held the title of the Stanford Federal Credit Union Professor of Humanities and Sciences at Stanford University and was an influential social psychologist who studied attributional biases, shortcomings in judgment and decision making, and barriers to conflict resolution, often with longtime collaborator Mark Lepper. Ross was known for his identification and explication of the fundamental attribution error and for the demonstration and analysis of other phenomena and shortcomings that have become standard topics in textbooks and in some cases, even popular media. His interests included ongoing societal problems, in particular protracted inter-group conflicts, the individual and collective rationalization o