Consideraciones éticas

A number of cognitive theories may have been postulated to account for psychopathy. Two particularly prominent theoretical frameworks have focused on the role of cognitive biases and of executive dysfunction. Turning to cognitive biases, according to a theory proposed by Lazarus (1991), the experience of emotion is determined by cognitive appraisal. This appraisal involves evaluating a situation in terms of its relationship to ‘schemata’. These are personal beliefs, values, relationships, goals and expectations that are based around personal experience. The outcome of this appraisal determines the nature of the emotion. For instance, consider the following example. A woman in her early twenties boarded a bus late at night. A man boarded the bus at the next stop and sat on the seat directly beside the young

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woman, despite the fact that the bus was almost completely empty. He stared at her for extended periods of time, and she thought she could feel his hand against her leg. The woman may have rapidly appraised the situation in terms of her knowledge and beliefs about the world and herself. She may have come to the following conclusions: (a) late-night travel can be unsafe; (b) there was nobody else on the bus; (c) the man was behaving suspiciously and may have posed a threat, and (d) she was likely to be physically weaker than him and did not have any sort of weapon; she would thus most likely be easily overpowered in a fight. Following this appraisal, the woman was likely to have experienced fear.

Since schemata are based upon personal experience, they may be subject to cognitive biases or distortions (Blackburn, 2005). These distortions include overgeneralising on the basis of one experience or only focusing on the negative aspects of a situation. Cognitive distortions have been posited as a mechanism by which emotional dysfunction arises. Thus, Blackburn (2006) proposes that psychopathy results from specific maladaptive beliefs about the self and the world, such as “I am stronger than others and deserve to succeed more”, “people are weak and stupid and should be exploited”or “cheating will help me to get ahead”. These can give rise to distorted self-evaluations and attributions about causality, and reduced empathy for others (Fernandez & Marshall, 2003). Some studies have found that in comparison with control participants, psychopathic individuals reported different beliefs and made different causal attributions about others, and concluded that this may relate to cognitive distortions (e.g. Widom, 1976; Klass, 1980; Serin, 1991). However, there is a paucity of evidence to suggest that deviant schemas predict deviant behaviour (Blackburn, 2007), and few studies have examined psychopathic schemata directly. Moreover, the key assumption of this framework is that cognitive appraisals lead to emotional responses (Lazarus, 1991). However, there is conflicting evidence suggesting that emotion occurs as an automatic response to a triggering event, and that cognitive reasoning is constructed post- hoc if necessary (Haidt, 2001). Taken together, there is some evidence suggesting that psychopathic traits, such as reduced empathy and a propensity for antisocial behaviour, could be explained by cognitive distortions, but further empirical work is needed.

Turning to executive function, this refers to the regulation and control of cognitive processes (e.g. Elliott, 2003). This is thought to be involved in active behavioural control as opposed to automatic or habitual responses. Thus, situations that involve planning, decision-making, error-correction, troubleshooting, novel sequences of actions, or those that require strong, habitual responses to be overcome are thought to require executive rather than automatic

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processes (Norman & Shallice, 1986). For instance, a familiar route to work may be relatively automatic and require little attention or advance planning. By contrast, taking a new route to work, updating a familiar route in light of unexpected roadworks, or taking public transport on a day that the car needs repairs may all involve executive function. There is some debate in the literature with respect to the precise number of executive functions (e.g. Baddeley, 1986; Shallice & Burgess, 1996; Petrides, 2000). However, the evidence broadly indicates the involvement of some key skills, such as the capacity to shift attention between tasks (cognitive flexibility), monitoring and updating information (working memory) and behavioural control (inhibition; Miyake, Friedman, Emerson et al., 2000).

Whilst theories have not explicitly linked psychopathy to executive dysfunction, it is noteworthy that psychopathic tendencies include features such as impulsivity, poor behavioural control and failure to plan ahead (e.g. Hare, 1991). All of these features could be accounted for by executive dysfunction. Moreover, as described above, the prefrontal cortex has been extensively linked to executive function (e.g. Stuss & Knight, 2002), and the orbital portion of the prefrontal cortex is thought to function abnormally in psychopathic people (Mitchell et al., 2002; Blair et al., 2001; Shamay-Tsoory et al., 2010; Blair, 2010). It is thus important to consider potential executive deficits in relation to psychopathy.

Neuropsychological paradigms have been developed in order to tap into the aspects of executive function referred to above. Cognitive flexibility has been examined using tasks such as the Wisconsin Card Sorting Test and the Trail-Making test. These tasks require participants to detect, understand and adapt to new rules. Studies have found those with psychopathy to be unimpaired on these tasks (Hare, 1984; LaPierre, Braun & Hodgins, 1995; Pham, Vanderstukken, Philippot & Vanderlinen, 2003). Some studies have recruited executive tasks and found that people with psychopathy fail to adapt their behavioural strategy in response to negative feedback (e.g. losing money in a gambling task). However, this is thought to relate to insensitivity to punishment rather than cognitive inflexibility (Mitchell et al., 2002; Blair et al., 2001).

With respect to working memory, this has been examined using tasks that require participants to manipulate information that they are temporarily holding in mind. For instance, one measure of working memory often used in the research literature is the ‘digits backward’subtest from the Wechsler Adult Intelligence Scale-III (WAIS-III; Wechsler, 1997). This task involves participants listening to sequences of numbers and repeating them

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in reverse order. Very limited work has examined working memory capacity in psychopathy. However, one study found that high PPI scores were not associated with impaired performance on the ‘digits backward’test (Sellbom & Verona, 2007).

Finally, inhibition has been examined using tasks such as the Stroop colour-word interference test, in which participants read colour-words (e.g. red, blue, green) printed in incongruently coloured ink (e.g. the word ‘red’written in blue ink). This incongruity is thought to interfere with the capacity to state the colour of the ink and to ignore the colour word. This interference results in slower response times, whereas failures of inhibition result in higher error rates. Despite the fact that psychopathy is associated with impaired behavioural inhibition (e.g. Hare, 1991), the evidence in relation to inhibition as measured by executive tasks is mixed. One study reported that those with psychopathy make more errors on the Stroop test than control participants (Pham et al., 2003). By contrast, other studies have found psychopathic performance comparable to control participants in terms of both the number of errors and the level of interference (Dvorak-Bertsch, Sadeh, Glass, Thornton & Newman, 2007; Hiatt, Schmitt & Newman, 2004; Smith, Arnett & Newman, 1992).

Taken together, the evidence in relation to executive deficits in psychopathy is somewhat mixed and no comprehensive executive theory has been formalised. Moreover, it is unclear whether deficits in inhibition truly represent executive dysfunction. For instance, inhibition may occur as a way of avoiding negative experiences. A range of studies has found that aversive conditioning and sensitivity to punishment is impaired in psychopathy (Peschardt et al., 2003; Blair et al., 2004). Thus, psychopathic individuals may primarily lack the motivation rather than the capacity to inhibit their behaviour. The evidence reviewed therefore suggests that psychopathy is unlikely to be adequately explained from a cognitive perspective; emotional accounts of psychopathy will therefore now be considered.