Negative Affectivity as an Explanation for the Overlap between Psychopathy and Post-Traumatic Stress Disorder

Martin Sellbom, Research School of Psychology, Australian National University, Canberra, Australia

The current study examined associations between psychopathy, its two facets of fearless-dominance and impulsive-antisociality, and posttraumatic stress disorder (PTSD) symptoms. It was hypothesized that the psychopathy facets would show respective differential negative and positive associations with PTSD symptoms; in turn, these associations were expected to be fully accounted for by negative affectivity. In a sample of 481 university students, psychopathy traits were differentially associated with PTSD symptoms as expected. Using structural equation modeling, it was found that negative affectivity explained 76% of the shared variance for PTSD and impulsive-antisociality; it accounted for 80% of the observed negative association between PTSD and fearless-dominance.

psychopathy, posttraumatic stress disorder, negative affectivity

Introduction
“Psychopathy and post-traumatic stress disorder (PTSD) are two serious and quite distinct forms of psychopathology with significant implications for the criminal justice system. Both are associated with greater offense rates, violence, and re-offending than the normative population. The association between these conditions, however, is complex. Some argue that they should not co-occur due to the fact that psychopathy is associated with reduced threat-sensitivity and poor fear conditioning, whereas PTSD is associated with heightened threat-sensitivity. Others contend that these disorders tend to both be associated with substantial histories of trauma exposure and should thus co-occur as a result” (p. 85).

“Research has established a weak to moderate association between PTSD and global psychopathy. More specific examination of the psychopathy facets in these studies indicates that this
positive association is entirely due to disinhibitory psychopathy traits (i.e., impulsivity, irresponsibility, sensation seeking, poor anger control). Subsequent research has shown that affective-interpersonal psychopathy traits (i.e., callousness, lack of empathy, remorselessness, shallow affect, grandiosity, deceitfulness, fearlessness) are negatively associated with PTSD, and that such traits are protective against development of this disorder when an individual is exposed to trauma” (p.85)

“One potential explanation for the overlap between psychopathy and PTSD is negative affectivity, which is a dispositional vulnerability towards anxiety, stress reactivity, anger, and other negative emotions…. while this literature suggests that negative affectivity can potentially explain the complex associations between psychopathy traits and PTSD symptoms, no research to date has explicitly tested this
hypothesis” (p. 85-86).

The Current Study
“The current investigation therefore sought to determine whether negative affectivity could account for the observed associations between psychopathy and PTSD. In the current investigation, psychopathy was considered from the perspective of the Psychopathic Personality Inventory (Lilienfeld & Andrews, 1996), which operationalizes psychopathy trait facets as fearless-dominance (affective-interpersonal, with a focus on an interpersonal dominance/assertiveness, manipulativeness, stress immunity, thrill and adventure seeking, and lack of anticipatory fear; thus, threat-insensitivity) and impulsive-antisociality (disinhibitory, with a focus on aggression, impulsivity, irresponsibility, nonplanfulness, and blame externalization). It was hypothesized that fearless-dominance would be negatively associated with PTSD, whereas impulsive-antisociality would be positively associated with this disorder. Further, it was hypothesized that trait negative affectivity would account for the shared variance between psychopathy and PTSD; thus, serving as a common vulnerability (for social deviance and PTSD) or invulnerability (affective-interpersonal and PTSD) factor. Finally, it was expected that fearless-dominance would serve as a protective factor (due to threat insensitivity) in the association between disinhibitory traits and PTSD, in that the association between the latter two would be substantially smaller in the presence of high scores on fearless-dominance” (p. 86).

The current study administered a series of questionnaires to 481 undergraduate students at a medium-sized Midwestern university. “The Minnesota Multiphasic Personality Inventory-2 (MMPI-2) was administered to all participants.From these data, a select set of MMPI-2 Restructured Form scales were scored, as these have been found to provide accurate estimates of psychopathy from the conceptual perspective of the Psychopathic Personality Inventory” (p. 86-87). Additionally, the PTSD Checklist – Civilian Version (PCL-C) and the Positive and Negative Affect Schedule – Extended version (PANAS-X) were administered.

Results
” Total psychopathy scores and PTSD symptoms were uncorrelated; however, consistent with hypotheses, a positive association between PTSD symptoms and impulsive-antisociality psychopathy traits and a negative association between fearless-dominance psychopathy traits and PTSD symptoms were found. Although the pattern of associations between psychopathy domains and these PTSD factors were the same, the correlations with the PTSD Dysphoria factor were generally larger than those with the other PTSD factors, which is not surprising given that this PTSD factor is most strongly linked to negative affectivity. Similarly, fearless-dominance evinced moderate negative correlations with both negative affectivity and its specific facets (guilt, fear, sadness, hostility), whereas impulsive-antisociality
was positively associated with the same” (p. 87-88).

“The findings support the hypothesis that the two primary psychopathy facets would have opposing associations with PTSD symptoms, and that such associations can be almost entirely explained by trait negative affectivity. The present findings also revealed that fearless-dominance traits have a protective effect against the presence of PTSD symptoms in those high on the impulsive-antisociality psychopathy facet” (p. 89).

“Fearless-dominance represents the reduction in threat sensitivity, and thus is a potential protective factor against internalizing psychopathology, whereas impulsive-antisociality represents a basic weakness in inhibitory control systems, including emotional regulation and anger control. Thus, any co-occurrence between psychopathy and PTSD is likely to be underpinned by a shared vulnerability to negative affective states, particularly with an externalizing phenotypic presentation. Taken together, the presence of PTSD symptoms in individuals high on psychopathy will likely be dictated based on differential levels of the two psychopathy factors … high levels of fearless-dominance incurred a protective effect, in that associations between impulsive-antisociality and PTSD symptoms were substantially smaller (and predicted PTSD scores substantially lower) in light of high fearless-dominance scores. Indeed, psychopathy is associated with structural abnormalities to the amygdala and associated deficits in the processing of affective information including fear” (p.89).

“The PTSD and anxiety disorders literatures have indicated that negative emotional reactions due to the traumatic experience are actually associated with a hyperactive (rather than hypoactive) amygdala and fear-responsivity. Thus, the current findings further supports the growing literature of primary psychopathy (i.e., presence of high fearless-dominance) being immune to the development of internalizing psychopathology, which was originally proposed by Cleckley (1941) in his seminal treatise The Mask of Sanity” (p. 89-90).

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