Widespread associations between trait conscientiousness and thickness of brain cortical regions

Gary Lewis, David Alexander Dickie, Simon Cox, Sherif Karama, Alan Evans, John Starr, Mark Bastin, Joanna Wardlaw, Ian Deary

Research output: Contribution to journalArticlepeer-review

Abstract

The neural correlates of human personality have been of longstanding interest; however, most studies in the field have relied on modest sample sizes and few replicable results have been reported to date. We investigated relationships between personality and brain gray matter in a sample of generally healthy, older (mean age 73 years) adults from Scotland drawn from the Lothian Birth Cohort 1936. Participants (N=578) completed a brain MRI scan and self-reported Big Five personality trait measures. Conscientiousness trait scores were positively related to brain cortical thickness in a range of regions, including bilateral parahippocampal gyrus, bilateral fusiform gyrus, left cingulate gyrus, right medial orbitofrontal cortex, and left dorsomedial prefrontal cortex. These associations – most notably in frontal regions – were modestly-to-moderately attenuated by the inclusion of biomarker variables assessing allostatic load and smoking status. None of the other personality traits showed robust associations with brain cortical thickness, nor did we observe any personality trait associations with cortical surface area and gray matter volume. These findings indicate that brain cortical thickness is associated with conscientiousness, perhaps partly accounted for by allostatic load and smoking status.
Original languageEnglish
Pages (from-to)22-28
Number of pages7
JournalNeuroImage
Volume176
Early online date14 Apr 2018
DOIs
Publication statusPublished - 1 Aug 2018

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