Nonlinearity within dark triad constructs? The case for psychopathy and Machiavellianism

Abstract

Building on recent findings corroborating nonlinear associations between vulnerable and grandiose narcissism, we explored the possibility of nonlinear relations between the dimensions of psychopathy and Machiavellianism, respectively. We tested the relations within Machiavellianism using the Five Factor Machiavellianism Inventory (FFMI) in a sample of 1315 participants, and within psychopathy using the Triarchic Psychopathy Measure (TriPM) in a sample of 1802 participants. Relations between dimensions were investigated via quadratic and segmented regression analyses. Contrary to narcissism, we did not find substantial nonlinear relations between the dimensions of psychopathy or Machiavellianism. We further explored the configuration of the overall scores for Machiavellianism and psychopathy and found that at high levels, FFMI and TriPM overall scores are driven by their respective antisocial dimensions and less by their adaptive components. Future studies might consider interactive combinations of the construct dimensions, e.g., Emergent Interpersonal Syndromes (EIS).