This is the first study to explore the relationship between Empathizing-Systemizing (E-S) theory that provides an account of sex differences in human cognition and dual process theories of cognition. 68 Undergraduates undertook both performance and self-report assessments of Empathizing, intuition, Systemizing and deliberation. A fast (500. ms) and slow (5000. ms) version of the Reading the Mind in the Eyes Task (RMET) was included to explore the effects of rapid presentation on emotional stimuli. Consistent with E-S theory, sex differences were found in Empathizing (favouring females) and Systemizing (favouring males). Females were also found to be more intuitive and males more deliberative for performance, but not self-report, assessments of intuition and deliberation. Empathizing significantly positively correlated with intuition and negatively with deliberation. Conversely, Systemizing significantly positively correlated with deliberation and negatively with intuition (trend). This pattern was replicated in a study of 65 participants from the general population. The exception was the RMET which had no significant sex differences or correlates (fast or slow). The implications for considering both dual process theories of cognition and E-S theory are discussed, with a focus upon the implications for Autism Spectrum Disorder and psychosis.