Rationality and intertemporal choice

The alleged problems associated with self-control, hyperbolic discounting and other examples of seemingly irrational intertemporal choice are examined in the context of an evolution-based neurobiological model that emphasizes the role of the biological evolution of big brains and language and the cultural evolution of institutions. There is no utility function in the brain; it has no central-planner, in fact, the brain is a self-organized complex system, a decentralized spontaneous order. This spontaneous order is coordinated, much like an economy, by a distributed network that maintains and makes available the discounted net value of various options to decentralized and specialized areas in the brain when making decisions. Further, that decision making is embodied and embedded in the decision making environment. For humans, an important part of that environment is the social environment consisting of institutions and other components of culture. It was, in part, the evolution of this environment that made long-range planning possible. Additionally, it is very often the lack of embedded experience with the environment that leads to what seems to be irrational intertemporal choices. In fact, under close examination the evidence for consistent irrational intertemporal choice is weak. © 2009 Springer Science+Business Media, LLC.