Gray matter correlates of dispositional optimism: a voxel-based morphometry study.

Dispositional optimism is an important product of human evolution. This individual difference variable plays a core role in human experience. Dispositional optimism is beneficial to physical and psychological wellbeing. Previous task-related neuroimaging studies on dispositional optimism were limited by small sample sizes, and did not examine individual differences in dispositional optimism related to brain structure. Thus, the current study used voxel-based morphometry and the revised Life Orientation Test to investigate individual dispositional optimism and its association with brain structure in 361 healthy participants. The results showed that individual dispositional optimism was associated with larger gray matter volume of a cluster of areas that included the left thalamus/left pulvinar that extended to the left parahippocampal gyrus. These findings suggest a biological basis for individual dispositional optimism, distributed across different gray matter regions of the brain.