The Economic Reductionism and Trust (Ir)rationality - Trust Theory: A Socio-Cognitive and Computational Model - page 229

8

The Economic Reductionism
and Trust (Ir)rationality

Trust is a traditional topic in economics, for obvious reasons: economic relationships, first of all
exchange, presuppose that X relies on Y for receiving what she needs (an item or a service, work
or salary); she has to trust Y on both competence and quality, and on his reliability (credibility,
honesty, fidelity). Trust is the presupposition of banks, money, commerce, companies, agency,
contracts, and so on.
So, trust has been the subject of several approaches by economists and social scientists
((Williamson, 1993), (Axelrod and Hamilton, 1981) (Yamagishi, 2003) (Pelligra, 2005; 2006]).
Many of them (often out of a desire to find a simple measure, some quantification, 1 ) are very
reductive, both from a psychological and a social point of view; the notion/concept itself is
usually restricted and sacrificed for the economic framework.
In addition, a lot of interesting considerations on trust have developed (a 'trust game' for
example, (Joyce et al. , 1995], (Henrich et al. , 2004]) around game theory: a recently growing
domain (Luce and Raiffa, 1957) (Axelrod and Hamilton, 1981), (Shoham and Leyton-Brown,
2009).
In this chapter we aim to discuss some of those ideas (which appear, quite diffused, in other
disciplines), showing why they are too reductive and how they miss fundamental aspects of
the trust phenomenon, crucial even in economics.
We will discuss the particular (and for us not acceptable) formulation of trust by Deutsch
(Deutsch, 1985) and in general the relationship between trust and irrationality (of the trustee
or of the trustor); the very diffused reduction of trust to subjective probability; Williamson's
eliminativistic position (Williamson, 1993); trust defined in terms of risk due to Y 's temptation
and opportunism; and as an irrational move in a strategic game; the reductive notion of trust in
the trust game, and in some socio-economic work (Yamagishi, 2003)); why (the act of ) trust
cannot be mixed up and identified with the act of cooperating (in strategic terms); the wrong
foundational link between trust and reciprocity. 2

1 We call this attitude: 'quanificatio precox'.
2 See for example (Pelligra, 2005) and (Castelfranchi, 2009).