The place of the rational actor model in the analysis of individual and social behavior relevant to law remains unresolved. In recent years, scholars have sought frameworks to explain: a) disjunctions between seemingly rational behavior and seemingly irrational behavior; b) the origins of and influences on law-relevant preferences, and c) the nonrandom development of norms. This Article explains two components of an evolutionary framework that, building from accessible insights of behavioral biology, can encompass all three. The components are: "time-shifted rationality" and "the law of law's leverage."