The neuroanatomical delineation of agentic and affiliative extraversion

Abstract

Extraversion is a fascinating personality dimension that consists of two major components, agentic extraversion and affiliative extraversion. Agentic extraversion involves incentive motivation and is expressed as a tendency toward assertiveness, persistence, and achievement. Affiliative extraversion involves the positive emotion of social warmth and is expressed as a tendency toward amicability, gregariousness, and affection. Here we investigate the neuroanatomical correlates of the personality traits of agentic extraversion and affiliative extraversion using the Multidimensional Personality Questionnaire brief form (MPQ-BF), structural magnetic resonance imaging (MRI), and voxel-based morphometry (VBM) methods in a sample of 83 healthy adult volunteers. We found that trait agentic extraversion and trait affiliative extraversion were each positively associated with the volume of the medial orbitofrontal cortex bilaterally (t’s ≥ 2.03; r’s ≥ .23, p’s <0.05). Agentic extraversion was specifically and positively related to the volume of the left parahippocampal gyrus (t = 4.08, r = .21, p < 0.05), left cingulate gyrus (t = 4.75, r = .28, p < 0.05), left caudate (t = 4.29, r = .24, p < 0.05), and left precentral gyrus (t = 4.00, r = .18, p < 0.05) in males and females, and the volume of the right nucleus accumbens in males (t = 2.92, r = .20, p < 0.05). Trait affiliative extraversion was not found to be associated with additional regions beyond the medial orbitofrontal cortex. The findings provide the first evidence of a neuroanatomical dissociation between the personality traits of agentic extraversion and affiliative extraversion in healthy adults.

Beyond sensation seeking: a conceptual framework for individual differences in psychostimulant drug effects in healthy humans

“…Metabolism in the orbitofrontal cortex also scales with combined measures of agentic and affiliative extraversion [21]. Agentic extraversion is uniquely correlated with the amount of gray matter in five additional brain regions – the left parahippocampal gyrus, left cingulate gyrus, left caudate, and left precentral gyrus [14]. This study also revealed intriguing gender differences, with only men showing correlations in the right nucleus accumbens.…”

“…These components are measured using separate personality scales and factors (for details see [10]), and modulate emotional and behavioral responses to incentive reward and social cues [12] [13]. These sub-components are mechanistically dissociable with agentic and affiliative extraversion relating to the response to dopamine and mu-opiate drugs, respectively [10] [14]. Pharmacologically, trait measures of extraversion predict responses to drugs that act through dopamine mechanisms such as bromocriptine, a D2 receptor agonist that causes greater eyeblink and prolactin responses in individuals with high trait extraversion [15], and methylphenidate, which causes greater context-related cue conditioning in individuals with high trait extraversion [16].…”

“…Recent investigation of neuroanatomical variation in healthy persons indicates that the agentic and affiliative components of extraversion map onto an overlapping yet distinct set of gray matter correlates in healthy adults [14]. Both agentic extraversion and affiliative extraversion are positively correlated with the amount of gray matter in the orbital frontal cortex [14]; see also [17] [18] [19]. Critically, this brain region is involved both in the mapping of rewards onto contexts as well as the acquisition of stimulant addiction [10] [20].…”

“…The positive mood response to amphetamine can be modulated by trait agentic extraversion [6] [23] [7] and other personality traits (fearlessness, impulsivity, absorption; see below). Separately, agentic extraversion has been found to relate to between-person differences in gray matter volumes in the nucleus accumbens, caudate, motor cortex and posterior cingulate [14] – regions involved in drug effects on emotion [24] and behavior [29] [30]. Together, these findings demonstrate substantial overlap between the functional domains impacted by stimulant drugs and extraversion.…”

Understanding the influence of personality on dynamic social gesture processing: An fMRI study

“…In so doing, extraversion has been shown to be positively related to regional volume of the medial orbitofrontal cortex (DeYoung et al, 2010; Grodin and White, 2015), nucleus accumbens (Grodin and White, 2015), left temporal cortex, dorsolateral prefrontal cortex (DLPFC), anterior cingulate (Grodin and White, 2015; Kapogiannis et al, 2013), and left amygdala (Omura et al, 2005); and negatively related to regional volume of the bilateral amygdala and parahippocampal (Lu et al, 2014), right middle temporal gyrus, inferior frontal gyrus (Bjørnebekk et al, 2013; Wright et al, 2006) and right temporoparietal junction (Forsman et al, 2012). On the other hand, also using VBM analysis, neuroticism has been positively associated with volume of right cerebellum (Lu et al, 2014), middle temporal gyrus and cingulate cortex (DeYoung et al, 2010; Omura et al, 2005); and negatively correlated with right orbitofrontal cortex, DLPFC, amygdala and precentral gyrus (DeYoung et al, 2010).…”