This chapter builds upon the triune modular brain concept of Paul MacLean to create a new model of our neural architecture called the conflict systems neurobehavioral (CSN) model. It develops reciprocal algorithms of behavior, involving the tug and pull between ego and empathy, neocortical representations of phylogenetically established self-preservation and affectional brain structures. These algorithms are applied to the ubiquitous phenomenon of social reciprocity. The same fundamental algorithms are further shown to be the underlying dynamic of social exchange as well as the transactional market governed by the so-called laws of supply and demand. The reciprocal algorithms are offered as the evolved mechanism complement to Hamilton’s rule of inclusive fitness. The linkage of their mathematical expressions is demonstrated. The neural algorithms are also expressed in the invisible hand concept of Adam Smith, which, as a basic economic concept, has been the source of much theoretical speculation in microeconomic theory. The linkage of Hamilton’s rule with the reciprocal neural algorithms combined with the sourcing of economic and social exchange in the neural dynamic allows a theoretical basis for the integration of evolutionary psychology with evolutionary neuroscience as a foundation for economics and the social sciences.

To proceed with developing the conflict systems neurobehavioral (CNS) model, I begin with the work of Paul D.MacLean. MacLean, who was founder and longtime chief of the Laboratory of Brain Evolution and Behavior of the National Institutes of Health, is our leading evolutionary neuroscientist. MacLean’s triune brain concept has been one of the most influential ideas in brain science since World War II (e.g., see Durant in Harrington 1992:268). Nevertheless, it has also been criticized in some quarters of neuroscience. ¹

-345-