Joumal of Abnormal Psychology 2014, Vol. 123, No. 1,205-213
© 2013 American Psychological Association 0021-843X/14/$12.00 DOI: 10.1037/a0035072
Examining the Relations Among Pain Tolerance, Psychopathic Traits, and Violent and Nonviolent Antisocial Behavior Joshua D. Miller, Steven Rausher, Courtland S. Hyatt, Jessica Maples, and Amos Zeichner University of Georgia Psychopathic traits are typically associated with an array of extemalizing behaviors including violent and nonviolent crime and recidivism, substance use, aggression, and sexual coercion. In the current study, we test the hypothesis that psychopathic traits are related to an increased tolerance for physical pain, which may partially account for the relations between psychopathy and antisocial behavior (ASB). Using community participants oversampled for psychopathic traits (N = 104), we found that psychopathic traits, measured using self- and informant reports, manifested small correlations with some measures of physical pain tolerance (tolerance of pressure and electric shock) but not others (tolerance of cold temperature). In addition, pain tolerance, particularly tolerance of pressure, manifested small correlations with a history of antisocial and aggressive behavior. However, there was little evidence that pain tolerance serves as a mediator of the relations between psychopathy and violent or nonviolent ASB. Conversely, there was evidence that the relations between pain tolerance and ASB were mediated by the presence of certain psychopathic traits. The implications of these findings are discussed. Keywords: pain tolerance, psychopathy, self and informant reports, antisocial behavior
Psychopathy is a personality disorder characterized by egocentricity, callousness, a lack of remorse or empathy, manipulativeness, impulsivity, and irresponsibility, as well as a predisposition toward antisocial behavior (ASB). Although often studied using categorical approaches, there is a general consensus that psychopathy is a dimensionally distributed construct (Guay, Ruscio, Knight, & Hare, 2007) that manifests a similar nomological network irrespective of the type of sample in which it is studied (e.g., Sellbom, 2011; Vachon, Lynam, Loeber, & Stouthamer-Loeber, 2012). Despite some debate regarding whether ASB is most appropriately considered a core component of psychopathy (Hare & Neumann, 2008) or a correlate (Skeem & Cooke, 2010), there is httle question that the two are closely linked. Extant research has shown that psychopathy is related to ASBs including aggression (Woodworth & Porter, 2002), violence (Kennealy, Skeem, Walters, & Camp, 2010), recidivism (Walters, Knight, Grann, & Dahle, 2008), and sexual coercion toward women (Knight & Guay, 2006). A variety of explanations have been put forth for the relation between psychopathy and ASB. From a personality perspective, psychopathy is composed primarily of traits related to interpersonal antagonism (e.g., callousness, egocentricity) and disinhibition (e.g., impulsivity; Miller, Lynam, Widiger, & Leukefeld, 2001)—both of which are among the most prominent personality trait correlates
of ASB and aggression (see Jones, Miller, & Lynam, 2011, for a review). Another possible explanation for the link between psychopathy and antisociality places an emphasis on the role of high trait fearlessness (Lykken, 1995), such that fearless individuals are difficult to socialize as punishment (real or anticipated) may have less of an aversive impact on them. A third theory suggests that psychopathic individuals have a deficient "violence inhibition mechanism," which is thought to be a basic, primitive system that encourages an aggressor to terminate his or her aggression in response to cues of distress or submission from the victim (Blair, 1995). Blair and colleagues have demonstrated that psychopathic individuals have deficits in processing others' verbal and nonverbal expressions of fear (Blair et al., 2002, 2004) and thus may miss cues that would encourage the cessation of aggression. In line with this theory. Caes and colleagues (2012) demonstrated that psychopathic traits in female undergraduate students were associated with a diminished ability to perceive pain experienced by others, as well as diminished fear in response to pain experienced by others. Although the data suggest that psychopathic individuals are less responsive to fear or pain experienced by others, there is relatively little recent research examining their own responses to physical pain. One might speculate that psychopathic individuals may be less responsive to self-experienced pain, which may make it more difficult for them to perceive or appreciate others' responses to pain. Being less responsive to self and others' experienced pain may then make it easier for psychopathic individuals to engage in ASB, especially those involving aggression/violence. Physical pain tolerance is associated with behaving aggressively toward others (Niel, Hunnicutt-Ferguson, Reidy, Martinez, & Zeichner, 2007; Reidy, Dimmick, MacDonald, & Zeichner, 2009; Séguin, Pihl, Boulerice, Tremblay, & Harden, 1996), as well as the ability to do harm to oneself (e.g.. Franklin, Hessel, & Prinstein, 2011). Data from a small sample (N = 12) of individuals with congenital insensitivity to pain suggest that these individuals can understand
This article was published Online First November 18, 2013. Joshua D. Miller, Steven Rausher, Courtland S. Hyatt, Jessica Maples, and Amos Zeichner, Department of Psychology, University of Georgia. Funding for this study was provided by the Owens Institute for Behavioral Research at the University of Georgia. Correspondence concerning this article should be addressed to Joshua D. Miller, University of Georgia, Psychology Building, Athens, GA 306023013. E-mail: [email protected] 205
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MILLER, RAUSHER, HYATT, MAPLES, AND ZEICHNER
and detect pain in others, although others' pain may be "greatly underestimated" (Danziger, Prkachin, & Wilier, 2006, p. 2494). There are also now data that indicate that the same neurological systems are activated when experiencing pain oneself and seeing someone else experience pain (Corradi-DeU'Acqua, Hofstetter, & Vuilleumier, 2011; Lamm, Decety, & Singer, 2011); as such, difficulties experiencing pain oneself may serve as a proxy for difficulties in empathizing with others' experiences of pain. With regard to psychopathy, the research literature suggests that psychopathic individuals may be slower to detect the presence of an electric shock but may not differ in their tolerance level for pain (see Hare, 1965, 1966, 1968; Schoenherr, 1964), although psychopathic individuals may tolerate more pain in response to incentives (Hare & Thorvaldson, 1970). Fedora and Reddon (1993) compared psychopathic prisoners (n = 28), nonpsychopathic prisoners (n = 28), and normal controls (n = 29) in relation to tolerance of electrical stimulation and found that both prisoner groups had substantially higher tolerances than the control group but did not differ from one another. The majority of these types of studies, however, have relied exclusively on electric stimulation as their means of measuring pain tolerance, studied these effects in very small samples of male offenders, and used a single psychopathy score rather than examining psychopathy at the facet or subscale level, the latter approach being more consistent with modem measurement approaches to psychopathy. In the current study, we examined the relations between selfand informant reporis of psychopathy, three measures of pain tolerance, and violent and nonviolent ASB. Multiple measures and source ratings of psychopathy were used so as to ensure that the currents results would not be due to idiosyncrasies in the conceptualization or assessment of psychopathy from one specific perspective. To that end, we chose two psychopathy treasures that were developed from entirely different perspectives. The SelfRepori Psychopathy Scale-III (SRP-III; Paulhus, Neumann, & Hare, in press) was developed to capture psychopathy as it has been conceived of and studied from the perspective of Psychopathy Checklist and measures derived from it (e.g.. Hare, 2003), whereas the Elemental Psychopathy Assessment (EPA; Lynam et al., 2011) was developed to assess the basic personality traits associated with psychopathy as conceptualized from a five-factor model perspective. The SRP-III contains two factors believed to be related to the interpersonal and affective aspects of psychopathy (Interpersonal Manipulation and Callous Affect), as well as two factors related to disinhibited traits and behaviors associated with psychopathy (Erratic Lifestyle and ASB). Alternatively, the EPA has four higher-order factors that measure trait-based components of psychopathy including Antagonism, Disinhibition, Emotional Stability, and Narcissism (Few, Miller, & Lynam, 2013). Together, these two psychopathy measures capture the core traits believed by many to be central to psychopathy, including those in the triarchic model of psychopathy (Patrick, Fowles, & Krueger, 2009), which comprises meanness (e.g., SRP-III Callous Affect and Interpersonal Manipulation; EPA Antagonism and Narcissism), disinhibition (SRP-III Erratic Lifestyle and ASB; EPA Disinhibition) and boldness (EPA Emotional Stability and Narcissism). In addition, we collected self- and informant ratings of psychopathy, given concerns that psychopathic individuals may be unwilling or unable to provide accurate data (cf. Miller, Jones, & Lynam, 2011). Similarly, pain tolerance was assessed in a multimodal manner and
included measures of tolerance of physical pressure, expostire to cold temperatures, and electric stimulation. Finally, we also examined multiple types of ASB that could be grouped broadly into violent and nonviolent composites. Analytically, we first examined the zero-order correlations among the self- and informant reports of psychopathy, ASB scores, and pain tolerance scores. We expected that the self- and informant psychopathy scores would be generally associated with extemalizing behaviors and that the psychopathy scales reflecting "meanness" (i.e., SRP-III Callous Affect; EPA Antagonism) would be most strongly related to physical pain tolerance. We then conducted two sets of mediation analyses. The first set of mediation models tested whether the relations between psychopathy and ASB (conducted separately for violent and nonviolent ASB) would be mediated, in pari, by higher levels of pain tolerance. We predicted that this would be the case for violent but not nonviolent behavior given that physical pain tolerance has previously been linked to aggressive behavior and a difficulty estimating others' experience of pain (Danziger et al., 2006; Reidy et al., 2009). This analysis provides a critical test as to whether pain tolerance may be an associated feature of psychopathy or a central mechanism by which psychopathic traits lead to ASB. The second set of mediation analyses, which were more exploratory in nature and examined multiple mediators simultaneously, tested whether the relations between pain tolerance and ASB were mediated by psychopathic traits.
Method Procedures and Participants Pariicipants were recruited via adveriisements placed in local newspapers, fliers placed around town, and word of mouth. Two variants of advertisements were used. To oversample for psychopathic traits, one version called for individuals who thought of themselves as charming, aggressive, carefree, impulsive, and irresponsible, but good at handling people and looking after "number one" (e.g., Widom, 1977). The other adveriisement did not include these characteristics but rather provided only generic information regarding a study on personality. Potential participants first completed a telephone screen to assess for inclusion criteria (between ages of 18 and 65; no current signs of psychosis; no current and regular use of analgesic medications; no acute or chronic pain disorders). Pariicipants were then scheduled for a laboratory assessment that included informed consent, completion of personality questionnaires, and the pain tolerance assessment. All pariicipants were run through the laboratory protocol by a male research assistant. Participants were asked to endure each of the three pain tolerance tasks for as long as they could and to indicate to the research assistant when they no longer wished to endure the task any longer because the stimuli were experienced as being painful. Pariicipants were paid $30 for their participation. Upon completion of the study, individuals were asked to provide email addresses for up to three individuals who knew them well. Informant reporis were then sought in a sequential manner (i.e., if informant #1 chose not to participate or did not respond to the email invitation, an invitation was sent to informant #2). If more than one informant ultimately completed the assessment (n = 7),
PSYCHOPATHY AND PAIN TOLERANCE the data from both informants were combined. Informants were reimbursed $10 for their participation. IRB approval was obtained for all aspects of this study. Self-report data were collected from 120 individuals. Data from 14 individuals were excluded because they provided invalid data as assessed by validity scales from the EPA or other markers (e.g., finished all self-report assessments in a time that was deemed implausible). Data from two individuals are not reported here because they did not complete the pain tolerance assessment. In the current study, data from 104 individuals with complete and valid data were used (M age = 30.9, SD = 10.8; 71% male; 64% White, 22% Black, 6% biracial, 8% Hispanic). The oversampling strategy appeared to have been successful as the mean SRP-III Total score was higher in the current study (M = 169.06, SD = 28.9) than the levels reported in Seibert et aL (2011; M = 147.78, SD = 27.2; í(232) = 5.75, p
© 2013 American Psychological Association 0021-843X/14/$12.00 DOI: 10.1037/a0035072
Examining the Relations Among Pain Tolerance, Psychopathic Traits, and Violent and Nonviolent Antisocial Behavior Joshua D. Miller, Steven Rausher, Courtland S. Hyatt, Jessica Maples, and Amos Zeichner University of Georgia Psychopathic traits are typically associated with an array of extemalizing behaviors including violent and nonviolent crime and recidivism, substance use, aggression, and sexual coercion. In the current study, we test the hypothesis that psychopathic traits are related to an increased tolerance for physical pain, which may partially account for the relations between psychopathy and antisocial behavior (ASB). Using community participants oversampled for psychopathic traits (N = 104), we found that psychopathic traits, measured using self- and informant reports, manifested small correlations with some measures of physical pain tolerance (tolerance of pressure and electric shock) but not others (tolerance of cold temperature). In addition, pain tolerance, particularly tolerance of pressure, manifested small correlations with a history of antisocial and aggressive behavior. However, there was little evidence that pain tolerance serves as a mediator of the relations between psychopathy and violent or nonviolent ASB. Conversely, there was evidence that the relations between pain tolerance and ASB were mediated by the presence of certain psychopathic traits. The implications of these findings are discussed. Keywords: pain tolerance, psychopathy, self and informant reports, antisocial behavior
Psychopathy is a personality disorder characterized by egocentricity, callousness, a lack of remorse or empathy, manipulativeness, impulsivity, and irresponsibility, as well as a predisposition toward antisocial behavior (ASB). Although often studied using categorical approaches, there is a general consensus that psychopathy is a dimensionally distributed construct (Guay, Ruscio, Knight, & Hare, 2007) that manifests a similar nomological network irrespective of the type of sample in which it is studied (e.g., Sellbom, 2011; Vachon, Lynam, Loeber, & Stouthamer-Loeber, 2012). Despite some debate regarding whether ASB is most appropriately considered a core component of psychopathy (Hare & Neumann, 2008) or a correlate (Skeem & Cooke, 2010), there is httle question that the two are closely linked. Extant research has shown that psychopathy is related to ASBs including aggression (Woodworth & Porter, 2002), violence (Kennealy, Skeem, Walters, & Camp, 2010), recidivism (Walters, Knight, Grann, & Dahle, 2008), and sexual coercion toward women (Knight & Guay, 2006). A variety of explanations have been put forth for the relation between psychopathy and ASB. From a personality perspective, psychopathy is composed primarily of traits related to interpersonal antagonism (e.g., callousness, egocentricity) and disinhibition (e.g., impulsivity; Miller, Lynam, Widiger, & Leukefeld, 2001)—both of which are among the most prominent personality trait correlates
of ASB and aggression (see Jones, Miller, & Lynam, 2011, for a review). Another possible explanation for the link between psychopathy and antisociality places an emphasis on the role of high trait fearlessness (Lykken, 1995), such that fearless individuals are difficult to socialize as punishment (real or anticipated) may have less of an aversive impact on them. A third theory suggests that psychopathic individuals have a deficient "violence inhibition mechanism," which is thought to be a basic, primitive system that encourages an aggressor to terminate his or her aggression in response to cues of distress or submission from the victim (Blair, 1995). Blair and colleagues have demonstrated that psychopathic individuals have deficits in processing others' verbal and nonverbal expressions of fear (Blair et al., 2002, 2004) and thus may miss cues that would encourage the cessation of aggression. In line with this theory. Caes and colleagues (2012) demonstrated that psychopathic traits in female undergraduate students were associated with a diminished ability to perceive pain experienced by others, as well as diminished fear in response to pain experienced by others. Although the data suggest that psychopathic individuals are less responsive to fear or pain experienced by others, there is relatively little recent research examining their own responses to physical pain. One might speculate that psychopathic individuals may be less responsive to self-experienced pain, which may make it more difficult for them to perceive or appreciate others' responses to pain. Being less responsive to self and others' experienced pain may then make it easier for psychopathic individuals to engage in ASB, especially those involving aggression/violence. Physical pain tolerance is associated with behaving aggressively toward others (Niel, Hunnicutt-Ferguson, Reidy, Martinez, & Zeichner, 2007; Reidy, Dimmick, MacDonald, & Zeichner, 2009; Séguin, Pihl, Boulerice, Tremblay, & Harden, 1996), as well as the ability to do harm to oneself (e.g.. Franklin, Hessel, & Prinstein, 2011). Data from a small sample (N = 12) of individuals with congenital insensitivity to pain suggest that these individuals can understand
This article was published Online First November 18, 2013. Joshua D. Miller, Steven Rausher, Courtland S. Hyatt, Jessica Maples, and Amos Zeichner, Department of Psychology, University of Georgia. Funding for this study was provided by the Owens Institute for Behavioral Research at the University of Georgia. Correspondence concerning this article should be addressed to Joshua D. Miller, University of Georgia, Psychology Building, Athens, GA 306023013. E-mail: [email protected] 205
206
MILLER, RAUSHER, HYATT, MAPLES, AND ZEICHNER
and detect pain in others, although others' pain may be "greatly underestimated" (Danziger, Prkachin, & Wilier, 2006, p. 2494). There are also now data that indicate that the same neurological systems are activated when experiencing pain oneself and seeing someone else experience pain (Corradi-DeU'Acqua, Hofstetter, & Vuilleumier, 2011; Lamm, Decety, & Singer, 2011); as such, difficulties experiencing pain oneself may serve as a proxy for difficulties in empathizing with others' experiences of pain. With regard to psychopathy, the research literature suggests that psychopathic individuals may be slower to detect the presence of an electric shock but may not differ in their tolerance level for pain (see Hare, 1965, 1966, 1968; Schoenherr, 1964), although psychopathic individuals may tolerate more pain in response to incentives (Hare & Thorvaldson, 1970). Fedora and Reddon (1993) compared psychopathic prisoners (n = 28), nonpsychopathic prisoners (n = 28), and normal controls (n = 29) in relation to tolerance of electrical stimulation and found that both prisoner groups had substantially higher tolerances than the control group but did not differ from one another. The majority of these types of studies, however, have relied exclusively on electric stimulation as their means of measuring pain tolerance, studied these effects in very small samples of male offenders, and used a single psychopathy score rather than examining psychopathy at the facet or subscale level, the latter approach being more consistent with modem measurement approaches to psychopathy. In the current study, we examined the relations between selfand informant reporis of psychopathy, three measures of pain tolerance, and violent and nonviolent ASB. Multiple measures and source ratings of psychopathy were used so as to ensure that the currents results would not be due to idiosyncrasies in the conceptualization or assessment of psychopathy from one specific perspective. To that end, we chose two psychopathy treasures that were developed from entirely different perspectives. The SelfRepori Psychopathy Scale-III (SRP-III; Paulhus, Neumann, & Hare, in press) was developed to capture psychopathy as it has been conceived of and studied from the perspective of Psychopathy Checklist and measures derived from it (e.g.. Hare, 2003), whereas the Elemental Psychopathy Assessment (EPA; Lynam et al., 2011) was developed to assess the basic personality traits associated with psychopathy as conceptualized from a five-factor model perspective. The SRP-III contains two factors believed to be related to the interpersonal and affective aspects of psychopathy (Interpersonal Manipulation and Callous Affect), as well as two factors related to disinhibited traits and behaviors associated with psychopathy (Erratic Lifestyle and ASB). Alternatively, the EPA has four higher-order factors that measure trait-based components of psychopathy including Antagonism, Disinhibition, Emotional Stability, and Narcissism (Few, Miller, & Lynam, 2013). Together, these two psychopathy measures capture the core traits believed by many to be central to psychopathy, including those in the triarchic model of psychopathy (Patrick, Fowles, & Krueger, 2009), which comprises meanness (e.g., SRP-III Callous Affect and Interpersonal Manipulation; EPA Antagonism and Narcissism), disinhibition (SRP-III Erratic Lifestyle and ASB; EPA Disinhibition) and boldness (EPA Emotional Stability and Narcissism). In addition, we collected self- and informant ratings of psychopathy, given concerns that psychopathic individuals may be unwilling or unable to provide accurate data (cf. Miller, Jones, & Lynam, 2011). Similarly, pain tolerance was assessed in a multimodal manner and
included measures of tolerance of physical pressure, expostire to cold temperatures, and electric stimulation. Finally, we also examined multiple types of ASB that could be grouped broadly into violent and nonviolent composites. Analytically, we first examined the zero-order correlations among the self- and informant reports of psychopathy, ASB scores, and pain tolerance scores. We expected that the self- and informant psychopathy scores would be generally associated with extemalizing behaviors and that the psychopathy scales reflecting "meanness" (i.e., SRP-III Callous Affect; EPA Antagonism) would be most strongly related to physical pain tolerance. We then conducted two sets of mediation analyses. The first set of mediation models tested whether the relations between psychopathy and ASB (conducted separately for violent and nonviolent ASB) would be mediated, in pari, by higher levels of pain tolerance. We predicted that this would be the case for violent but not nonviolent behavior given that physical pain tolerance has previously been linked to aggressive behavior and a difficulty estimating others' experience of pain (Danziger et al., 2006; Reidy et al., 2009). This analysis provides a critical test as to whether pain tolerance may be an associated feature of psychopathy or a central mechanism by which psychopathic traits lead to ASB. The second set of mediation analyses, which were more exploratory in nature and examined multiple mediators simultaneously, tested whether the relations between pain tolerance and ASB were mediated by psychopathic traits.
Method Procedures and Participants Pariicipants were recruited via adveriisements placed in local newspapers, fliers placed around town, and word of mouth. Two variants of advertisements were used. To oversample for psychopathic traits, one version called for individuals who thought of themselves as charming, aggressive, carefree, impulsive, and irresponsible, but good at handling people and looking after "number one" (e.g., Widom, 1977). The other adveriisement did not include these characteristics but rather provided only generic information regarding a study on personality. Potential participants first completed a telephone screen to assess for inclusion criteria (between ages of 18 and 65; no current signs of psychosis; no current and regular use of analgesic medications; no acute or chronic pain disorders). Pariicipants were then scheduled for a laboratory assessment that included informed consent, completion of personality questionnaires, and the pain tolerance assessment. All pariicipants were run through the laboratory protocol by a male research assistant. Participants were asked to endure each of the three pain tolerance tasks for as long as they could and to indicate to the research assistant when they no longer wished to endure the task any longer because the stimuli were experienced as being painful. Pariicipants were paid $30 for their participation. Upon completion of the study, individuals were asked to provide email addresses for up to three individuals who knew them well. Informant reporis were then sought in a sequential manner (i.e., if informant #1 chose not to participate or did not respond to the email invitation, an invitation was sent to informant #2). If more than one informant ultimately completed the assessment (n = 7),
PSYCHOPATHY AND PAIN TOLERANCE the data from both informants were combined. Informants were reimbursed $10 for their participation. IRB approval was obtained for all aspects of this study. Self-report data were collected from 120 individuals. Data from 14 individuals were excluded because they provided invalid data as assessed by validity scales from the EPA or other markers (e.g., finished all self-report assessments in a time that was deemed implausible). Data from two individuals are not reported here because they did not complete the pain tolerance assessment. In the current study, data from 104 individuals with complete and valid data were used (M age = 30.9, SD = 10.8; 71% male; 64% White, 22% Black, 6% biracial, 8% Hispanic). The oversampling strategy appeared to have been successful as the mean SRP-III Total score was higher in the current study (M = 169.06, SD = 28.9) than the levels reported in Seibert et aL (2011; M = 147.78, SD = 27.2; í(232) = 5.75, p
