Trait Extraversion and Dopamine Function

Abstract

An inf luential theory within personality neuroscience suggests that trait extraversion is underpinned by individual differences in dopamine function. In a review of the relevant literature, we evaluate this theory in light of the evidence from molecular genetics, neuroimaging, and psychopharmacology. Evidence linking individual differences in extraversion with dopamine-relevant genes, structural volume of dopamine-rich brain regions (e.g., in striatal and ventral prefrontal areas), dopamine receptor availability, and frontal alpha asymmetry is mixed at best. Evidence concerning both scalp recorded (electroencephalogram) and hemodynamic (functional magnetic resonance imaging) neural responses to rewards appears somewhat more promising. Perhaps the best evidence concerns extraversiondependent responses -both neural and behavioural -to dopaminergic drugs. Future research in this area must go beyond the demonstration of theoretically consistent associations and attempt to provide more specific causal evidence for the dopamine hypothesis of extraversion. A further challenge is to expand this hypothesis to incorporate other neurobiological processes that are likely to underlie this trait.

Effects of positive emotion, extraversion, and dopamine on cognitive stability‐flexibility and frontal EEG asymmetry

“…The present observations that the extraversion correlations on both the behavioral and physiological levels (measure of stability‐flexibility derived from AX‐CPT reaction times and ASY) are completely reversed under the selective D2 receptor blocker sulpiride provides further support for the DA theory of extraversion (Depue & Collins, ; Wacker & Smillie, ) and extends Wacker et al's (, ) prior findings by (a) showing that the modulating effects of sulpiride on the association between extraversion‐spectrum traits and ASY is not restricted to males and self‐ratings of personality but generalizes to females and partner ratings of personality, and by (b) providing initial evidence for the suggestion that previously reported differences between introverts' and extraverts' performance in n ‐back working memory tasks (Lieberman & Rosenthal, ; Wacker et al, ) may result from individual difference in the stability‐flexibility balance. The latter suggestion will be further probed using data from the same research project by examining the multivariate associations between the stability‐flexibility measure analyzed in the present report, performance in the n ‐back task, an alternative measure of stability‐flexibility derived from a different task (Dreisbach & Goschke, ), an indicator of the potentially related dimension of broad versus narrow cognitive scope (Gable & Harmon‐Jones, ), and dopaminergic candidate genes previously associated with both stability‐flexibility (Colzato et al, ; Markett, Montag, Walter, Plieger, & Reuter, ) and extraversion spectrum traits (Smillie, Cooper, Proitsi, Powell, & Pickering, ; Wacker, Mueller, Hennig, & Stemmler, ).…”

“…At the very least, the present findings further bolster Wacker and Smillie's () conclusion that the link between extraversion and individual differences in DA is now already quite firmly established, and that it is time for research to move beyond the mere demonstration of this association by focusing on “(1) the causal role of dopamine in extraverted behavior, (2) the specificity of the association to agentic extraversion (vs. affiliative extraversion and other traits) and to particular features of dopamine functioning, (3) the mediating neural and psychological processes, and (4) the (moderating) contributions of other neurochemical systems” (Wacker & Smillie, , p. 233).…”

“…This facilitated responding to all sorts of incentives renders extraverts more enduring, motivated, and vigorous in their pursuit of positive incentive goals, thus explaining their characteristic patterns of behavior. By now, this dopamine theory of extraversion is the dominant neurobiological account for this trait, and the link between extraversion and individual differences in dopamine function has indeed been quite firmly established (Wacker & Smillie, ).…”

The Emerging Neuroscience of Intrinsic Motivation: A New Frontier in Self-Determination Research

“…Pharmacological manipulations of dopamine thus represent an important new research direction. Indeed, such manipulations have already been fruitfully applied in the study of dispositional traits (e.g., Wacker and Smillie, 2015) and their application in the study of motivational states would seem a natural extension. Pharmacological manipulations of dopamine may, for example, allow researchers to more precisely decode the neural mechanisms that mediate the undermining effect of externally contingent rewards on intrinsic motivation.…”

Trait compassion is associated with the neural substrate of empathy

“…Unlike Extraversion and Neuroticism, which have been extensively studied in personality neuroscience because of their links to basic reward and threat processes and their inclusion in older personality models (for reviews, see Allen & DeYoung, 2017;Shackman, Tromp, Stockbridge, Kaplan, Tillman, & Fox 2016;Wacker & Smillie, 2015), Agreeableness has received relatively little attention. Two small resting state fMRI studies found that Agreeableness is positively associated with functional connectivity within major hubs of the default network (Adelstein et al, 2011;Sampaio et al, 2014), a finding consistent with the theory that understanding and anticipating the mental states of others is facilitated by this network (Andrews-Hanna, Smallwood, & Spreng, 2014).…”