Executive functions neither associated with agentic extraversion nor sensitive to the dopamine D2 blocker sulpiride in a preregistered study

Abstract

Initial studies suggest that extraversion and executive functions (EFs) are associated because of shared dopaminergic mechanisms. Aiming to conceptually replicate these findings we conducted a preregistered study to investigate (1) associations between extraversion and performance in three tasks (3-back, switching, AX-CPT) and (2) whether these associations are sensitive to administration of the dopamine D2 receptor blocker sulpiride in a placebo-controlled between-subjects design (N = 200). Against expectations, neither (agentic) extraversion, nor its interaction with substance condition explained performance in any of the EF tasks. As the current results are limited by an unexpectedly low reliability of the measures derived from the switching task and the AX-CPT, further preregistered studies using psychometrically superior measures are needed.