1. Introduction
Is rational social interaction possible? This may seem a sur-
prising question, given the Apollonian flavor of the con-
temporary behavioral and social sciences. Rational choice
theory (RCT) is the cornerstone of neoclassical economics
(Arrow et al. 1996; Elster 1986; Sugden 1991b). In political
science, RCT began to mushroom after the publication of
Social Choice and Individual Values (Arrow 1963) and
transformed the discipline within a few decades (Friedman
1996; Green & Shapiro 1994; Ordeshook 1986). In sociol-
ogy, Weber’s (1922/1968) analyses of law and economics as
models of rationality prepared the ground for the germina-
tion of RCT ideas half a century later (Abell 1991; Coleman
& Fararo 1992; Hollis 1987; Moser 1990). Theories of be-
havioral ecology (Dawkins 1989; Krebs & Davies 1987),
and particularly, the evolution of social behavior (Maynard
Smith 1984), were revolutionized by the introduction of
RCT-based game theory in the early 1970s (Maynard Smith
& Price 1973); and even jurisprudence has been influenced
by RCT (Raz 2000).
1.1. Rationality in psychology
In psychology, the picture is admittedly more complex.
Since the publication of Freud’s earliest metapsychological
writings, and in particular his adumbration of the distinc-
tion between two principles of mental functioning, the
BEHAVIORAL AND BRAIN SCIENCES (2003) 26, 139–198
Printed in the United States of America
© 2003 Cambridge University Press
0140-525X/03 $12.50
139
Cooperation, psychological game
theory, and limitations of rationality
in social interaction
Andrew M. Colman
School of Psychology, University of Leicester, Leicester LE1 7RH,
United Kingdom
amc@le.ac.uk
www.le.ac.uk/home/amc
Abstract: Rational choice theory enjoys unprecedented popularity and influence in the behavioral and social sciences, but it generates
intractable problems when applied to socially interactive decisions. In individual decisions, instrumental rationality is defined in terms
of expected utility maximization. This becomes problematic in inte