Social Psychology and the Law

Abstract

Virtually every aspect of legal rules and procedures relies on assumptions about human psychology— about how individuals think, feel, and make decisions. Economics focuses on how people behave and interact as economic agents; psychology also focuses on human behavior and interaction, with specific attention to the influence of social and mental processes. Sometimes the law implicitly or explicitly incorporates findings from psychological science. For example, the law of negligence accounts for some of the limitations of human judgment in hindsight (Rachlinski, 1998). Because the hindsight bias is part of folk wisdom, legal rules have responded accordingly, such as in patent law where non- obviousness is determined by reference to secondary considerations like commercial success to “guard against slipping into the use of hindsight” (Rachlinski, 1998). But sometimes folk wisdom misunderstands human behavior and decision- making processes. Thus, for example, most people deem it unthinkable that an innocent person would confess to a crime she did not commit, in the absence of physical torture. And when folk wisdom misses the mark, it is more likely that judges, legislators, and other legal actors will fail to account for what psychological science might tell us about the human behavior in question. As one pioneer of the field of law and psychology observed over a century ago, “[Jurists] go on thinking that their legal instinct and their common sense supplies them with all that is needed” (Munsterberg, 1908). This chapter examines some of the implicit psychological assumptions about human behavior embedded in legal rules and practices. We narrow our focus specifically to social psychology, which we define as the scientific study of the ways in which individuals’ thoughts, feelings, and behaviors are influenced by the real, implied, or imagined presence of others (Allport, 1924).