Openness to Experience, also referred to as Openness/Intellect, is a broad and complex personality factor characterized by cognitive exploration. The expanded domain of Openness to Experience encompasses not only the general factor and its facets but also peripheral variables such as Intelligence and Psychoticism. Psychoticism is considered the maladaptive variant of the general Openness/Intellect factor. However, studies suggest that it represents a pathological version specifically of the Openness aspect, with the Intellect aspect potentially serving as a protective factor against it. Thus, the aim of the present article was to examine the relationships between Psychoticism and variables comprising what we define as the expanded domain of Openness to Experience. In Study 1, the Cognitive Flexibility Inventory was adapted to the Brazilian context, demonstrating adequate validity and reliability. Cognitive Flexibility was positively associated with Openness/Intellect, Self-Reflection, and Insight, and negatively associated with Dogmatism and Neuroticism. In Study 2, Psychoticism replicated expected correlations, showing positive associations with Openness and Self-Reflection and negative associations with Intellect, Cognitive Flexibility and Insight. A linear regression analysis revealed that Insight was the strongest individual predictor of Psychoticism. Finally, mediation analyses indicated that Openness is consistently associated with Psychoticism, while Intellect is not, as Control and, subsequently, Insight fully mediated its relationship.