IV. 6 Unión Popular de Vendedores Ambulantes (UPVA) 28 de octubre
IV. 7.2 Panorama y aspectos generales del conflicto en el movimiento Antorchista
Two theories have been offered to explain the formation of delusions from a
psychological perspective (Bentall and Kaney, 1989). The first, proposed by Maher
(1974, 1988) suggests that delusions are a result of normal cognitive processes that
are attempting to explain abnormal perceptual events (e.g. hallucinations). For
example, it has been shown that deaf people may be more likely to be paranoid (e.g.
Kay, Cooper, Garside and Roth 1976). This may be due to the fact that if you are
unable to hear what people are saying there may be a tendency to believe that others
are talking about you (Bentall 1990b). However, Bentall and Kaney (1989) argue that
for holding delusional beliefs. The second approach has suggested that abnormal
reasoning may be associated with the formation of delusional beliefs. This approach
has focused on finding experimental evidence of reasoning biases in people with
delusions. Its findings are specifically relevant to the present study and so these
studies will be outlined in detail.
Huq, Garety and Hemsley (1988) examined the performance of deluded subjects on a
probabilistic reasoning task. In its most simplistic form, this type of task involves two
jars being filled with beads of two colours e.g. red and blue. The ratio of the number
of beads in each jar is different (e.g. 70 red and 30 blue in one jar, 30 red and 70 blue
in the other). The jars are then removed from sight and beads are then repeatedly
drawn, shown to the participant and replaced. The participant must guess which jar
the beads are being drawn from. Huq et al. (1988) found that deluded participants
made a decision more quickly (i.e. required less evidence) and were more confident in
their judgements. It was therefore suggested that this represented an abnormal
reasoning bias, with deluded subjects being more likely to reach decisions with
confidence based on very little evidence.
Dudley, John, Young and Over (1997) completed a probabilistic reasoning study
where participants were given all the information that they needed prior to the
experiment. In this experiment deluded participants reasoned in a similar way to
normal participants. However when deluded participants were allowed to determine
how much evidence they needed, they requested less evidence and showed a pattern
similar to that found by Huq et al (1988). Dudley et al (1997) therefore concluded that
decision on the basis of less evidence. They suggest that this may be related either to
an attempt to reduce their personal investment in the decision or that they may be less
willing to entertain other hypotheses or tolerate ambiguity.
Kaney and Bentall (1989) examined the attributional style of deluded individuals.
They note that studies have shown that depressed individuals tend to make internal,
stable and global attributions about events, particularly negative events. Kaney and
Bentall compared the attributional style of paranoid individuals, depressed individuals
and normal controls. The depressed patients showed the pattern just described, but the
deluded patients tended to make external attributions for negative events and internal
attributions for positive events. Deluded participants also made significantly more
external attributions for negative events than normal controls. The tendency to
attribute negative events to an external source and positive events to oneself has been
observed in the normal populations. However, this “self serving bias” was found by Kaney and Bentall to be more extreme in deluded participants than for normal
controls. Although this study used individuals with persecutory delusions a study by
Fear, Sharp and Healy (1996) showed a similar pattern for patients with non-
persecutory delusions.
Bentall, Kaney and Dewey (1991) asked deluded, normal and depressed individuals to
make attributions to explain social vignettes in which an actor behaves in a particular
way towards a target person. Participants could chose from three possible attributions;
person attributions (e.g. “Something about Sally caused her to say that she liked
Kim”), circumstance attributions (e.g. “Something about the circumstance made Sally
Sally say that she liked her”) (Bentall, Kaney and Dewey, 1991: pp. 16). Half the
items were positively valued and half negatively (e.g. Sally says she likes Kim, Sally
hits Kim). Participants were also given information about the situation. McArthur
(1972) had shown that normal subjects are more likely to attribute to the target person
not the actor if the information is distinctive to the target person (the actor does not
exhibit that behaviour to other people), consistent with the actors previous behaviour
to the target person and if there is a consensus about actions towards the target person
(other people behave that way towards the target person). Bentall, Kaney and Dewey
found that although all three groups were more likely to make person attributions in
the presence of low information (behaviour not distinctive or consistent and there is
not a consensus), deluded participants were more likely to make person attributions in
the presence of high contextual information. In other words, the deluded participants
were less likely to blame the victims than the other groups in the study, even when
information suggested that the action of the actor was in some way justifiable.
However, deluded subjects did make less person attributions in the presence of high
contextual information than they did when contextual information was low. This
shows that the deluded participants did take account for the differences in contextual
information. Bentall, Kaney and Dewey suggest that this demonstrates that deluded
subjects have a reasoning bias, not a deficit, as they were able to take account of the
information. Furthermore, the deluded participants were more confident in their
judgements. Bentall, Kaney and Dewey suggest that the unwillingness to blame the
victim in social situations may suggest that this serves a protective function.
Studies examining attributions made by deluded individuals have therefore shown that
events and internal attributions for positive events, and that in social situations that
did not involve themselves they were less likely to blame the victim. Lyon, Kaney and
Bentall (1994) further investigated the attributions of individuals experiencing
persecutory delusions. Consistent with previous findings, when deluded participants’
attributions for events were explicitly measured, they made external attributions for
negative events. However, participants were also asked to make attributions on
hypothetical vignettes that were presented as a memory test. It is argued that this
implicitly measures attributional style. On this measure, deluded participants scored in
a similar way to depressed participants, making more internal attributions for negative
events and making external attributions for positive events. Thus when attributions are
measured explicitly, deluded participants show an extreme form of a self serving bias
that is found in normal participants (i.e. a tendency to blame others for negative
events and to take credit for positive events). When attributions are implicitly
measured, this is reversed and deluded individuals show the same pattern as depressed
individuals. Lyon et al. (1994) argue that consistent with cognitive studies, explicit
measures take effort and make demands on attention, whereas implicit measures are
fast and effortless and do not make demands on attention. They suggest that this is
similar to the distinction between conscious and unconscious processes outlined by
psychoanalytic theory. This raises the possibility that persecutory delusions serve a
defensive purpose that protects against a negative self-concept. This has been further
investigated by the use of Stroop tests, outlined below.
Bentall and Kaney (1989) compared the performance of paranoid deluded, depressed
and normal participants on an emotional Stroop test. In a Stroop test, lists of words
word, and the time taken to do this for the whole list is measured. In Bentall and
Kaney’s study, the words were either a series of Os, emotionally neutral words,
depressive words or threat related (paranoid) words. Studies have shown that
depressive subjects take longer to complete the task when they are reading depressive
words (e.g. Gotlib and McCann 1984), as the meaning of the words and the colours
compete for attention (Bentall and Kaney, 1989). Bentall and Kaney found that
depressed subjects took longer to complete the list of depressive words, and paranoid
subjects took longer to complete the list of threat related words. This suggests that
paranoid individuals show an attentional bias to threat related words. It is also
interesting to note that the model of PTSD outlined earlier by Brewin et al (1996)
suggested that premature inhibition of traumatic events is likely to lead to a bias
towards threat related information.
In a fiirther study by Kinderman (1994), participants were asked to state from a list of positive and negative words, whether they felt the words were like them or not.
Deluded participants endorsed more positive words and less negative words than
depressed individuals. Some of these words were then used to form positive and
negative lists of words in a Stroop test. On the Stroop test, deluded participants
showed a slower performance on positive and negative words than they did for neutral
words. Depressed individuals were only slower for negative words and normal
participants showed no differences. The Stroop test can be considered an implicit
measure of whether words were personally meaningful, and the endorsement of words
an explicit measure. Thus when asked explicitly deluded participants were less likely
to endorse negative words, but the Stroop test suggests these words did have personal
et al. (1994) suggesting that persecutory delusions may defend against a negative self-
concept.
The studies presented here have therefore demonstrated that deluded individuals have
a tendency to jump to conclusions based on very little evidence. They have also
demonstrated an explicit tendency to attribute negative events to external sources,
positive events to themselves and to be less likely to blame the victim in situations
that do not involve themselves. However, when attributions are measured implicitly,
studies suggest that deluded individuals do make internal attributions for negative
events.
Bentall, Kinderman and Kaney (1994) note that depression is characterised by a gulf between one’s perception of oneself and an ideal view of oneself. They suggest that
persecutory delusions may be a result of trying to reduce that gap. Bentall et al (1994)
note that it is well established that self-concept develops during childhood and that
parents have a crucial role in its development. They therefore suggest that the findings
of the studies above imply that there is a need to research how family processes might
be implicated in the development of the cognitive biases shown by deluded
individuals.