Law, Selfishness, and Signals: An Expansion of Posner’s Signaling Theory of Social Norms

Eric Posner’s signaling theory of social norms holds that individuals adopt social norms in order to signal that they have a low discount rate, and are therefore reliable long-term cooperative partners. This paper radically expands Posner’s theory by incorporating internalization into his model. I do this by tethering Posner’s theory to an evolutionary model. I argue that internalization is an adaptive quality that enhances the individual’s ability to play Posner’s signaling game and was thus selected for. The idea that internalization is evolutionarily conditioned is not new; however, linking this to Posner’s theory of discount rate signals is, and doing so offers tremendous explanatory potential.Part I identifies the limitations of Posner’s purely rational choice approach, argues for the necessity of including internalization, and then proposes a model that does so – what I call the Expanded Signaling Model of Norms. Part II examines the problems that arise when we embrace such a model. How this model answers some key criticisms plaguing sociobiology is also briefly explored. Part III then examines existing criticisms of Posner’s theory, demonstrating how the Expanded Signaling Model clearly resolves these issues. The paper concludes that incorporating internalization into Posner’s signaling model greatly broadens the explanatory reach of Posner’s theory, providing a measure of clarity and predictability regarding how and why norms are internalized – an important insight, as these beliefs form the normative underpinning to law.