This paper resolves a fundamental paradox in legal evolution: how self-interested actors create and maintain cooperative legal orders without centralized enforcement. Drawing on Dawkins' analysis of biological altruism, we demonstrate that commercial law emerges through three mechanisms that parallel biological evolution: kin selection (generating trust networks in early merchant communities), reciprocal altruism (creating self-enforcing contracts and trade customs), and costly signaling (establishing reputational systems that enable anonymous exchange). Historical analysis of merchant law from ancient Mesopotamia through medieval Europe to modern international commerce reveals that cooperative legal orders consistently emerge through evolutionary pressures rather than sovereign imposition. The lex mercatoria, Jewish diamond merchants, Islamic hawala networks, and contemporary international arbitration all exhibit the same evolutionary pattern: cooperation emerges from iterated interactions among self-interested traders who develop legal norms as extended phenotypes of their survival strategies. We formalize these dynamics through evolutionary game theory, showing that legal cooperation represents an evolutionary stable strategy (ESS) under conditions of repeated interaction, reputation tracking, and network exclusion. The paper challenges both Hobbesian assumptions about the necessity of sovereign enforcement and romantic notions about merchant virtue, demonstrating instead that commercial law represents an extended phenotype of human reciprocal altruism. These findings explain why commercial law shows remarkable consistency across cultures and millennia, why merchant communities resist state intervention in their dispute resolution, and why reputational sanctions often exceed legal penalties in effectiveness. The implications extend beyond commercial law to any legal domain where repeated interactions among identifiable actors create conditions for reciprocal altruism to evolve.This research employs computational literature analysis and AI-assisted synthesis tools, disclosed in accordance with transparency standards for AI use in academic research. All theoretical frameworks, legal interpretations, and scholarly arguments are original work by the author.
Ignacio Adrian LERER (Tue,) studied this question.