The Negative Side: Lack of Trust, Implicit Trust, Mistrust, Doubts and Diffidence - Trust Theory: A Socio-Cognitive and Computational Model - page 124

Probability of P not
giving credit to Y

Realistic
Failure
Evaluation

Evidences/
Probability in favor
of P

Evidences/
Probability in
favor of Not-P

Gap of
Ignorance

X

Figure 4.6 Be prudent

of beliefs and evidence (pros or cons); but also this lack of evidence, assumed as unfavorable,
as suspect.
A 'diffident' attitude consists, on the one hand, of being vigilant and alarmed (worrying
about possible harms), on the other hand, precisely in being prudent, not giving credit , not
believing without evidence, being pessimistic and taking as potentially negative all the unclear
possibilities (see Figure 4.6).
As we said, the perceived ignorance must not necessarily be ascribed in favor of P or
Not-P . It can be just neutral, as perceived lack of information; and perhaps the decision will
be suspended. This entails - as we said - that when trust ( ) is not sufficient for entrusting, its

complement, is mistrust; it can just be perceived ignorance (Figure 4.7).
Notice that in a sense,

γ

represents the estimated probability of a failure (of Not-P ) and thus
a crucial component of the perceived 'risk' that might have a specific threshold (Chapter 3). X
might not accept a given level of

ω

, and thus renounces on betting on Y if the bad evidence on
Y is too great. Clearly, this is independent of the positive trust and on its acceptance threshold.
For example, if

ω

is at the 15% - like in our previous example - it might be acceptable;
while if it was at 30% (even still being

ω

at the 55%) the risk might be unacceptable. As we
said, X may decide not to trust Y because trust is not enough, not because distrust is greater
than trust, or because all the rest is distrust.
We will develop in Chapter 8 a more complete analysis of 'Optimism' and also the fact that
both trust and distrust are actually 'self-fulfilling prophecies', with important consequences on
'rationality' of trust bet, on trust dynamics (Chapter 6), on trust spreading and self-organization.

γ