The anatomical structure of sex differences in trust propensity: A voxel-based morphometry study

Nooshin Safari; Huihua Fang; Apoorva Veerareddy; Pengfei Xu; Frank Krueger

doi:10.1016/j.cortex.2024.02.018

The anatomical structure of sex differences in trust propensity: A voxel-based morphometry study

Cortex. 2024 Apr 8:S0010-9452(24)00089-3. doi: 10.1016/j.cortex.2024.02.018. Online ahead of print.

Authors

Nooshin Safari¹, Huihua Fang², Apoorva Veerareddy¹, Pengfei Xu³, Frank Krueger⁴

Affiliations

¹ School of Systems Biology, George Mason University, Fairfax, VA, USA.
² Shenzhen Key Laboratory of Affective and Social Neuroscience, Magnetic Resonance Imaging, China; Department of Psychology, University of Mannheim, Mannheim, Germany.
³ Beijing Key Laboratory of Applied Experimental Psychology, National Demonstration Center for Experimental Psychology Education (BNU), Faculty of Psychology, Beijing Normal University, Beijing, China; Center for Neuroimaging, Shenzhen Institute of Neuroscience, Shenzhen, China. Electronic address: pxu@bnu.edu.cn.
⁴ School of Systems Biology, George Mason University, Fairfax, VA, USA; Department of Psychology, University of Mannheim, Mannheim, Germany.

PMID: 38677959
DOI: 10.1016/j.cortex.2024.02.018

Abstract

Trust is a key component of human relationships. Sex differences in trust behavior have been elucidated by parental investment theory and social role theory, attributing men's higher trust propensity to their increased engagement in physically and socially risky activities aimed at securing additional resources. Although sex differences in trust behavior exist and the neuropsychological signatures of trust are known, the underlying anatomical structure of sex differences is still unexplored. Our study aimed to investigate the anatomical structure of sex differences in trust behavior toward strangers (i.e., trust propensity, TP) by employing voxel-based morphometry (VBM) in a sample of healthy young adults. We collected behavioral data for TP as measured with participants in the role of trustors completing the one-shot trust game (TG) with anonymous partners as trustees. We conducted primary region of interest (ROI) and exploratory whole-brain (WB) VBM analyses of high-resolution structural images to test for the association between TP and regional gray matter volume (GMV) associated with sex differences. Confirming previous studies, our behavioral results demonstrated that men trusted more than women during the one-shot TG. Our WB analysis showed a greater GMV related to TP in men than women in the precuneus (PreC), whereas our ROI analysis in regions of the default-mode network (dorsomedial prefrontal cortex [dmPFC], PreC, superior temporal gyrus) to simulate the partner's trustworthiness, central-executive network (ventrolateral PFC) to implement a calculus-based trust strategy, and action-perception network (precentral gyrus) to performance cost-benefit calculations, as proposed by a neuropsychoeconomic model of trust. Our findings advance the neuropsychological understanding of sex differences in TP, which has implications for interpersonal partnerships, financial transactions, and societal engagements.

Keywords: Gender differences; Gray matter volume; Trust; Trust game; Trust propensity.