رابطه بین اختلالات روانی و فراموشی مربوط به جرم و جنایت

The objective of this study was to investigate whether levels of psychopathy predicted claims of crime-related amnesia. Different characteristics of psychopathy were based on the factor structure of the self-report questionnaire Psychopathic Personality Inventory (PPI). Crime-related amnesia claims were scored from inmates (N = 31) criminal file records. Results demonstrated that claims of crime-related amnesia were more frequently reported by individuals scoring high on impulsive antisocial psychopathy traits. Furthermore, offenders who claimed crime-related amnesia reported lower levels of instrumental/proactive aggression. There was no relationship between fearless–callous psychopathy traits or the use of reactive violence, and claims of crime-related amnesia. Within offenders who claimed amnesia for their crime, the majority demonstrated elevated levels of deception, suggesting that claims of amnesia might serve a strategic purpose. In addition, they more often reported having had a previous experience with memory loss, which may have formed the basis of simulation.

In about 35% of the homicide cases, offenders claim amnesia for their crime (Bourget and Whitehurst, 2007 and Kopelman, 1995). According to Hopwood and Snell (1933), the memory loss in homicide cases often has to do with strong emotions and/or substance abuse at the time of the crime, and is therefore referred to as a type of dissociative amnesia. There is, however, a lot of debate about the credibility of such claims of dissociative amnesia (Cima, Nijman, Merckelbach, Kremer, & Hollnack, 2004). In a study by Woodworth et al. (2009), 50 Canadian homicide offenders were asked to describe their memories of their homicide. Findings indicated that the memory for the homicide was actually enhanced. The authors suggest that this is due to the powerful emotions often associated with committing a homicide. Interestingly, in a study by Woodworth and Porter (2002), 125 inmates were examined regarding the type of homicide they committed. These homicides were then categorized as being either a reactive, emotional, and impulsive crime of passion, or a primarily instrumental act which was premeditated and motivated by an external goal. Results of that study showed that psychopaths who were incarcerated for homicide committed a more instrumental act, while non-psychopathic offenders more often committed a reactive, emotional homicide. Several studies have investigated the psychological characteristics of offenders who report crime-related amnesia (e.g., Bourget and Whitehurst, 2007, Cima, Merckelbach, Hollnack and Knauer, 2003 and O'Connell, 1960). It has been demonstrated that, compared to offenders who do not claim amnesia, amnestic offenders show diminished executive (frontal lobe) functioning, lower IQ, and a tendency to feign symptoms (Cima, Merckelbach, Hollnack and Knauer, 2003 and Cima, Merckelbach, Hollnack, et al., 2003). In addition, amnesia-claimers demonstrate higher levels of hysterical traits (manipulation and antisocial personality disorder) in comparison to offenders who do not report memory loss. Given the overlap between an antisocial personality disorder and psychopathy (Widiger, 2006), as well as the core characteristics of psychopathy being manipulation and deception (Hare, 1991), one might also expect a relationship between psychopathy and claims of crime-related amnesia. In the last two decades, there has been an increasing interest in the construct of psychopathy. It has now been generally accepted that psychopathy is a complex personality disorder, which includes relatively distinctive personality traits and is often associated with a criminal or socially deviant life style (Hare and Neumann, 2009 and Hart and Hare, 1997). Psychopaths are generally viewed as a distinct subgroup of irresponsible, dishonest, superficial, manipulative, and emotionally disturbed people (Hart & Hare, 1997). Since it is believed that psychopaths show more manipulative behavior and malinger more frequently than non-psychopathic criminals in order to gain personal advantage, claims of amnesia need to be interpreted with great care in psychopathic offenders (Christianson et al., 2007 and Porter et al., 2001). To measure psychopathy, the Psychopathic Checklist Revised (PCL-R; Hare, 1991) is often administered by clinicians. However, Lilienfeld and Andrews (1996) developed a similar measurement of psychopathy that is based on self-report instead of observation; the Psychopathic Personality Inventory (PPI; Lilienfeld & Andrews, 1996). The PPI constitutes a dimensional approach of the concept of psychopathy. Factor analysis by Benning, Patrick, Hicks, Blonigen and Krueger (2003) revealed that scores on the PPI are underpinned by two largely orthogonal factors, comparable to the two factors identified by the PCL-R (Benning et al., 2003). The first factor is called the Fearless Dominance factor and is associated with a lack of social and physical anxiety. The second factor is termed Impulsive Antisociality, and is associated with a lack of impulse control, ruthlessness, and an insouciant flaunting of social norms. Due to their emotional shallowness, lack of social and moral norms, and their manipulative behavior, psychopaths often engage in planned offenses in order to serve a specific goal such as achieving money, sexual opportunities or increased status (Blair, 2003 and Porter et al., 2001). Since psychopathy is related to emotional under arousal and goal-directed behavior (e.g., Blair, 2003 and Herpertz et al., 2001), it is often assumed that they demonstrate premeditated, instrumental aggression (e.g., Porter et al., 2001 and Walsh et al., 2009). Instrumental (or predatory, proactive, and cold-blooded) aggression requires forethought and is a planned attack. In line with this, Chase, O'Leary, and Heyman (2001) found that predatory offenders are often having an antisocial personality style. Recently, a number of studies have been conducted with respect to the instrumental–reactive dimension of aggression (e.g., Cima and Raine, 2009, Poulin and Boivin, 2000 and Ross and Babcock, 2009). There has been increasing evidence that people who engage in impulsive and affective-driven aggression differ significantly from people who show more goal-directed, predatory aggression (Cima and Raine, 2009 and Raine et al., 1998). In contrast to instrumental aggression, impulsive aggression (also called: hot blooded, reactive, affective or defensive aggression) is spontaneous, immediate and emotion-driven. Reactive violence occurs as a response to perceived threats or frustrations. This reactive response to interpersonal provocation goes along with high affective–physiological arousal and minimal cognitive processing (Chase et al., 2001). Recent research has shown that a dimensional approach of reactive aggression and proactive aggression would more accurately explain the overlap between impulsive and predatory offenders. Although impulsive aggression and predatory aggression have distinct correlates, individuals can vary in their expression of both reactive aggression and proactive aggression (Cima & Raine, 2009). With respect to memory for instrumental and reactive violence, Cooper and Yuille (2007) demonstrated that reactive offenders, who committed an impulsive crime resulting from an agitated mood state, displayed poorer memory of the event compared to instrumental offenders. Cooper and Yuille (2007) argue that reactive offenders commit their crime in an exaggerated, impulsive state in which dissociation is more likely to occur. The motivation to use violence for these offenders is internal and due to an intense rage at the moment of crime (Cooper & Yuille, 2007). Accordingly, focusing on the source of affect during a reactive act of violence will lead to poorer memory for the event. Furthermore, impulsive offenders appear to be more sensitive to stress-inducing situations. In acts of reactive violence, high levels of arousal may lead to a narrowed and disrupted focus of attention resulting in perceptual deficits (e.g., Christianson et al., 1996). As a consequence, impulsive offenders may have poorer memory for the details of the event (Cooper & Yuille, 2007). In contrast, offenders who show premeditated, planned aggression appear to have high quality recall because the violence is often used to serve a well-planned external (e.g., financial) goal requiring a focus on the event. In addition, they are more likely to fantasize about the violence prior to engaging in it, thereby enhancing memory for the event (e.g., Porter et al., 2001). As previously mentioned, there has been some evidence that psychopathic offenders more often commit well-planned, instrumental acts of violence and demonstrate more proactive aggression (Blair, 2003 and Porter et al., 2001). Given that offenders who show instrumental aggression are believed to have better recollections about their violent act, claims of amnesia among psychopaths are doubtful. One might therefore expect that psychopaths, who claim amnesia for their crime, show an increased tendency to malinger. Pathological lying and the use of conning and manipulative behavior are two of the core personality features of psychopathy (Hare, 1991), which suggests that psychopaths may be more likely to engage in malingering than other offenders. This line of reasoning is supported by the finding that psychopathic offenders have better memory for their crimes than non-psychopathic offenders (Cooper, 2005). Their good quality memory may be due to the fact that psychopathic offenders often engage in planned (instrumental) offenses (Porter & Woodworth, 2007; Woodworth & Porter, 2002) resulting in enhanced memory (Brown and Craik, 2000 and Porter et al., 2001). The older study of Lynch and Bradford (1980) reported that offenders with antisocial personality traits have, indeed, a higher propensity to feign amnesia for crimes compared to those without such traits. Similarly, Gacono, Meloy, Sheppard, Speth, and Roske (1995) demonstrated that psychopathic offenders have higher malingering scores (see also Cima, Pantus, & Dams, 2007). However, with the exception of these two studies all others have failed to document a robust connection between psychopathy and the tendency to feign psychopathological symptoms. Thus, offenders with high psychopathy levels have not been found to be more likely to malinger psychiatric disorders (Kucharski, Duncan, Egan, & Falkenbach, 2006) or amnesia (Cima, Merckelbach, Hollnack and Knauer, 2003, Cima, Merckelbach, Hollnack, et al., 2003, Cooper and Yuille, 2007 and Herve et al., 2007) than offenders with low psychopathy levels. Neither were individuals with high psychopathy levels more successful in beating malingering tests than control individuals (Poythress, Edens, & Watkins, 2001). It would seem that the tendency to malinger may be more related to juridical context than personality disorder alone. That is, when there is something to gain (e.g., pre-trial) malingering may reduce criminal responsibility (Cima et al., 2007). A type of malingering that mental health professionals or legal decision makers frequently observe is feigned amnesia. Feigning memory loss may serve to support a legal defense (provocation and intoxication) and is often used as a way to raise doubt about ones involvement in the crime. It may also be a strategy to raise sympathy from jurors or family members (Porter et al., 2001). This is supported by the finding that claims of amnesia are more frequent at the beginning of the police investigation and become less frequent throughout the investigation (Christianson et al., 2007). Another possibility however, may be that amnesia is more likely to occur in psychopathic individuals of the impulsive antisocial type. As this subtype of psychopath tends to engage in more reactive acts of violence, they may experience perceptual deficits and memory loss for the event in question. The first goal of the present study was to investigate the relation between different factors of psychopathy (e.g., fearless dominance factor vs. impulsive antisocial factor) and claims of amnesia in an offender population. In line with the findings of Cooper and Yuille (2007) showing that impulsive offenders more often report dissociative amnesia for their crimes than instrumental offenders (Porter & Woodworth, 2007), it was hypothesized that offenders with psychopathic traits related to the impulsive antisocial factor would more frequently report amnesia for their crime than offenders with psychopathic traits related to the fearless dominance factor. According to Cooper and Yuille (2007), the level of emotional arousal during reactive acts of violence, may be responsible for the dissociative amnesia. Therefore, our second hypothesis was that overall high levels of self-reported reactive aggression (irrespective of psychopathy factors) would be more predictive for claims of amnesia, than high levels of self-reported proactive aggression. Since the study of Cooper and Yuille (2007) did not take deception into account, the current study also examined the relationship between malingering and claims of crime-related amnesia. On a related note, it has been suggested that claims of amnesia could be based on expectations of memory loss due to a previous experience with memory loss (Van Oorsouw & Cima, 2007). That is, previous experience with memory loss may form an expectancy-based basis of simulation (Kopelman, 2000). Therefore, our final hypothesis was that, if expectations play a role in claims of crime-related amnesia, offenders who claim amnesia would more often report a previous experience with memory loss, (e.g., an alcohol blackout) than offenders who do not claim amnesia.