The Negative Side: Lack of Trust, Implicit Trust, Mistrust, Doubts and Diffidence - Trust Theory: A Socio-Cognitive and Computational Model - page 114

Not Bel Trustworthy AND
Not Bel Not Trustworthy

Doubt

Trust

Mistrust

(Bel
Trustworthy) (Bel Not

Trustworthy)

Lack of Trust
(Not Bel Trustworthy)

Lack of Mistrust
(Not Bel Not Trustworthy)

Figure 4.2 Trust, Mistrust, Lack of Trust, Lack of Mistrust, Suspect, Doubt

Correspondingly, within the 'space' of lack of trust, clearly there is no trust. However, it is
perfectly possible and usual that X 'in part' trusts Y (and perhaps enough to delegate to Y ) and
'in part' doesn't trust or even mistrusts Y . 6
More than this: any trust implies some degree of mistrust or at least a lack of trust and
doubt . Since we do not admit that trust is the total certainty and evidence, and we claim that
in any case trust entails some (at least implicit ) risk of failure or some perceived ignorance.
Vice versa, any mistrust too is not certainty, and presupposes some (although minimal) doubt
in favor. This is a general theory about beliefs with a degree of certainty, and applies to
evaluation, to expectations, etc. For example, any hope - by definition - implies some worry;
and any worry (implicitly) contains some hope; although the complementary mental state is
not necessarily derived (it can remain just implicit) or focused on. (See Chapter 2).

4.3 The Complete Picture
We have also to add: 'X believes that Y is reliable' ('trust'), which is the only state incompatible
with 'lack of trust': formula (4.1) . However, this case also implies another belief and is a sub-
case of its extension: ' X does NOT believe that Y is NOT reliable/trustworthy' ( Not (Bel X (Not
(Trustworthy Y))) ).
The complete picture (including also 'suspicion') is shown in Figure 4.2.
Here we can see that - obviously - 'trust' and 'mistrust' exclude each other, while 'lack
of trust' and 'lack of mistrust' are not fully incompatible; they partially overlap in an area of
'doubt'. 'Diffidence' is not explicitly represented; it would be a specification within the entire
area of 'lack of trust' or of 'mistrust', that is, of the doubt or 'suspicion' that there might be

6 This does not deny that when we use the expression 'I trust' usually we in practice intend 'I trust enough', while
when we use the expression 'I do not have trust' we mean 'I do not have enough trust'. Similarly, when we say 'tall'
we actually mean 'taller than the norm/average'. But this is not logically necessary; it is just a pragmatic implication.
This is why there is no logical contradiction while saying: 'I distrust, I'm diffident, but not enough for not entrusting
him'.