Evolutionary theories of norms converge on two explanations for their origin and persistence: the adaptation-for-cooperation hypothesis (Boyd, Richerson, Henrich) and the uncertainty-reduction hypothesis (Sterelny and Brusse, 2026). Both accounts leave open a specific explanatory gap: why do patently dysfunctional norms, ones whose costs are visible to all actors, remain entrenched across multiple governmental cycles rather than being corrected? This paper proposes a mechanism that closes that gap. I argue that structurally unenforceable norms, those whose compliance is technically or economically impossible for the regulated population, evolve a secondary function through a process of cultural exaptation: they systematically suppress the political voice of regulated agents who are permanently in violation. I term this the Lateral Silencing Exaptation (LSE). The mechanism operates as follows: chronic non-compliance generates a standing vulnerability to discretionary enforcement; that vulnerability imposes an asymmetric cost on protest or political demand; rational agents therefore reduce or suppress regulatory contestation even on matters unrelated to the original norm. The paper develops a two-case typology: intentional LSE, where the silencing function is selected by design or by deliberate tolerance (illustrated by the Georgian regulatory apparatus under Eduard Shevardnadze, 1992-2003); and emergent LSE, where silencing arises as an unselected byproduct of overcomplexity, subsequently coopted as a governance resource (illustrated by Argentina's dual-control environmental and tax regulatory regimes). I formalize the transition from bug to feature using an evolutionary game theory framework: once a regulatory actor observes the silencing effect, the expected payoff from maintaining the dysfunctional norm strictly dominates that from correcting it, locking the norm into a durable equilibrium. This is precisely the Zombie Law Equilibrium described in prior work in this research program (Lerer, 2025; DOI 10.5281/zenodo.18943464). The paper integrates three bodies of literature that have not been connected: the theory of exaptation in institutional evolution (Gould and Vrba, 1982; as applied in Lerer, 2026); the political economy of extractive institutions (Acemoglu and Robinson, 2012); and the evolutionary theory of norm persistence under social opacity (Sterelny and Brusse, 2026). Falsifiable predictions are provided.
Ignacio Adrián LERER (Fri,) studied this question.