Biological evidence for individual differences in the ability to control immediate impulses in favour of longer-term goals: Conscientiousness as a personality trait

Conscientiousness, as one of the 'Big Five' personality traits, describes individualdifferences in the ability to constrain immediate impulses in favour of longer-term goals.It has a clear biological basis, with a heritability of 0.38-0.53, but attempts to identifyspecific genetic variants responsible have generally been unsuccessful, demonstratingthat the personality trait is influenced by a large number of genes. Studies focussing onimpulsivity and constraint indicate that serotonergic responsivity is positively associatedwith conscientiousness, although a number of neurotransmitters may be implicated.Imaging studies have revealed that dorsal anterior cingulate cortex (ACC), dorsolateralprefrontal cortex (DLPFC) and lateral orbitofrontal cortex (OFC) activation is alsopositively associated with the personality trait. It is thought that the dorsal ACC evaluateswhen to engage impulsive control whilst the DLPFC implements the control whilstassessing ones thoughts and longer-term goals. In addition to individual differences inserotonergic responsivity and activity in the above brain areas, the personality trait mayalso be influenced by individual differences in glucose metabolism. Future researchshould take a multimodal approach in order to produce a more definitive biologicalmodel.