Definitions of Trust: From Conceptual Components to the General Core - Trust Theory: A Socio-Cognitive and Computational Model - page 13

1.5 A Critique of Some Significant Definitions of Trust
At the beginning of this chapter we introduced our aim to review the predominant definitions
of trust in the literature, motivated by the purpose of showing that, in cognitive and social
sciences, there is not yet a shared or prevailing, and clear and convincing notion of trust .
After a content analysis of a larger number of definitions, let us now consider some specific
definitions in order to show how they frequently are incomplete, vague or obscure, domain
specific, divergent. To show this, we will be a bit simplistic and not completely fair with the
authors, just discussing and criticizing their definitions of trust. This is useful for comparing
them, and for stressing confusion, inaccuracy, and ad hoc features; but it is quite ungenerous,
since sometimes the analysis or theory of the author is more rich and correct than their
'definition'. However, several authors are more extensively discussed here or in other chapters
of this topic.
1.5.1 Gambetta: Is Trust Only About Predictability?
Let us first consider the definition of trust provided in the classic topic of Gambetta and
accepted by the great majority of other authors (Gambetta, 1988): 'Trust is the subjective
probability by which an individual, A , expects that another individual, B , performs a given
action on which its welfare depends ' (translation from Italian).
In our view, this definition is correct, insofar as it stresses that trust is basically an estimation,
an opinion, an expectation, i.e. a belief. We also find commendable that there is no reference
to exchange, cooperation, mutuality, and B 's awareness of being trusted by A , since none of
these features is, in our view, part of the core notion of trust.
However, Gambetta's definition is also too restricted in a variety of respects:
It just refers to one dimension of trust ( predictability ), while ignoring the competence
dimension.
It does not account for the meaning of ' A trusts B ' where there is also the decision to rely
on B .
It does not explain what such an evaluation is made of and based on, since the measure of
subjective probability collapses together too many important parameters and beliefs, which
each has its own role and relevance in social reasoning.
It fails to make explicit the 'evaluative' character of trust.
Finally, reducing trust to the notion of 'subjective probability' is quite risky, since it may
result in making superfluous the very notion of 'trust' (on this point, see Williamson's
criticism (Williamson, 1993) as well as Chapter 8).
1.5.2 Mayer, Davis, & Schoorman: Is Trust Only Willingness,
for Any Kind of Vulnerability?
Mayer, Davis, and Schoorman provide an interesting and insightful (albeit somehow limited)
definition of trust, as follows: 'The willingness of a party to be vulnerable to the actions of
another party based on the expectation that the other party will perform a particular action