The Dark Triad traits of Psychopathy, Machiavellianism, and Narcissism should be clearly recognizable within a multidimensional personality space. Two such personality spaces were investigated in this study: HEXACO (Honesty-Humility, Emotionality, Extraversion, Agreeableness, Conscientiousness, and Openness to Experience); and the Zuckerman-Kuhlman-Aluja Personality Questionnaire (ZKA-PQ) space (Extraversion, Neuroticism, Activity, Sensation Seeking, and Aggressiveness). Our sample comprised 289 participants (137 males, 145 females, 7 unspecified) who completed these three questionnaires: HEXACO–60, ZKA-PQ/SF, and the SD3, assessing the Dark Triad. We reduced the dimensionality of each space to that of a 2D representation using Smallest Space Analysis (SSA). Three research questions guided the data analysis: (a) Do the HEXACO and ZKA-PQ SSA spaces conform to the structure of a radex? (b) Will these spaces remain invariant following the entry of the Dark Triad traits into the analyses? (c) Where will the Dark Triad traits be located in each SSA space? For ZKA-PQ space, the structure was clearly indicative of a radex, both prior to entering the Dark Triad traits into the analysis, and subsequent to this. Psychopathy and Machiavellianism were in close proximity in the Aggressiveness region; Narcissism was positioned at the common origin. In contrast, HEXACO space did not conform to a radex; furthermore, the presence of the Dark Triad traits distorts this 2D SSA space.
