Researchers have suggested that the way in which the brain makes choices may be influenced by how extraverted you are.
The work is part of a growing body of research on the vital role of understanding personality in society.
"Understanding how people differ from each other and how that affects various outcomes is something that we all do on an intuitive basis, but personality psychology attempts to bring scientific rigor to this process," Colin DeYoung from the University of Minnesota said.
"Personality affects academic and job performance, social and political attitudes, the quality and stability of social relationships, physical health and mortality, and risk for mental disorder," he said.
In the new study, DeYoung and colleagues scanned people in an fMRI and asked them to choose between smaller immediate rewards or larger delayed rewards, for example 15 dollars today versus 25 dollars in three weeks. They then correlated their choices and associated brain activity to various personality traits.
They found that extraversion predicts neural activity in a region of the brain called the medial orbitofrontal cortex, which is involved in evaluating rewards. In the task, this region responded more strongly to the possibility of immediate rewards than to the possibility of delayed rewards.
"This is a brain region where we have previously shown that extraversion predicts the size of the region, so our new study provides some converging evidence for the importance of sensitivity to reward as the basis of extraversion," DeYoung said.
More broadly, DeYoung works on understanding "what makes people tick, by explaining the most important personality traits, what psychological processes those traits represent, and how those processes are generated by the brain," he said.
"The brain is an incredibly complicated system, and I think it's impressive that neuroscience is making such great progress in understanding it. Linking brain function to personality is another step in understanding how the brain makes us who we are," DeYoung said.
The findings of the study have been presented in a special session about personality psychology at a conference in New Orleans.