New research published in biopsychology We are investigating the relationship between psychotic fearlessness and defensive cardiac reactivity. A new finding suggests that women with high scores for the fearless psychopath trait tend to have reduced heart rate variability when faced with intense and unexpected stimuli. However, this relationship was not found among men.
Previous research has found that people with certain psychopathic traits have less automatic startle responses to threat. This is thought to be related to the fearlessness characteristic of psychopathy.
In addition to the startle response, other physiological measures, such as decreased muscle tone and decreased heart rate in certain situations, have also been associated with psychopathy. Research has also been done to combine these various measures to create an index of ‘threat sensitivity’, which may serve as a way to quantify and further study these characteristics.
A new angle in this research is to look at something called the cardioprotective response (CDR). It is a complex pattern of heart rate changes in response to sudden and unexpected threats or shocks. CDR is reflected in changes in heart rate and other cardiovascular parameters and is thought to represent activation of the sympathetic branch of the autonomic nervous system, which is responsible for triggering the ‘fight or flight’ response to perceived threat.
The researchers hypothesized that the CDR could be a useful new measure to study fearlessness traits in psychopathy. They were particularly interested in the second accelerated phase of CDR. This is because it appears to be related to readiness to respond to threats.
The study involved 156 participants (60 males) who completed the Revised Psychopathic Personality Inventory (PPI-R), a self-reported measure of psychopathic tendencies. The questionnaire examines a range of traits, including social influence, stress tolerance, fearlessness, Machiavellian self-centeredness, defiant incompatibility, externalizing responsibility, carefree unplannedness, and ruthlessness.
A defensive psychophysiological test measuring CDR was performed, in which participants were exposed to an unexpectedly intense white noise stimulus after an 8-min rest period. They were told they were participating in a study recording resting electrocardiograms, but future noise was not mentioned. Their heart rates were recorded from his 15 seconds before stimulus onset to his 80 seconds after stimulus onset.
The study found that men outperformed women in almost all aspects of psychopathy. In addition, men tended to have greater heart rate changes (both increases and decreases) in response to louder noise than women. This is especially true between specific points in time after the noise has been played.
Heart rate responses to loud noise were associated with some of the personality traits measured by the PPI-R questionnaire. Specifically, women who scored higher in the ‘fearlessness advantage’ (composed of traits such as social influence, stress tolerance, and fearlessness) had lower average heart rate changes in response to loud noise.
Looking more closely at the components of the ‘fearlessness advantage’ factor, we found that women who scored higher on the ‘fearlessness’ trait had a lower heart rate increase, especially during the ‘second acceleration’ phase of the defensive response (the phase in which heart rate increases after an initial deceleration, a process associated with preparing the body to respond to threat). This is true even when controlling for the influence of other traits on the Fearless Governance Factor.
This finding is important because it indicates gender-specific associations between fear-related traits and the body’s defensive responses. This study suggests that the heart’s response to threat may be a useful way to study the fearlessness that manifests in psychopathy and understand how this differs in men and women.
The research team acknowledged some limitations. First, the study used self-report measures of psychopathy, which may be biased and may not accurately capture all aspects of psychopathy. Furthermore, the relatively small sample size used in this study may limit the generalizability of the results. Finally, this study did not examine other potential factors that may influence the relationship between psychotic fearlessness and CDR, such as childhood trauma and other environmental factors.
the study, “Psychotic fearlessness and low cardioprotective reactivity as a physiological correlate: gender differences.’ was written by V. Blancader, R. Poi, P. Segara, P. Ribes-Guardiola and J. Morto.
