Neuroanatomical correlates of temperament in early adolescents

Temperament refers to enduring behavioral characteristics that underpin individual differences in human behavior, including risk for psychopathology. Research attempting to investigate the neurobiological basis of temperament represents an important step toward elucidating the biological mechanisms underlying these individual differences. In the present study, we examined the relation between four core temperament dimensions and anatomically defined regions of the limbic and prefrontal cortices.

We used a cross-sectional design to examine a large sample (N = 153; mean age 12.6 years, SD 0.4, range 11.4-13.7) of healthy early adolescents who were selected from a larger sample to maximize variation in temperament. The main outcome measures were psychometric measures of temperament (four factors: effortful control, negative affectivity, surgency, and affiliativeness) based on the Early Adolescent Temperament Questionnaire-Revised, and volumetric measures of a priori brain regions of interest (anterior cingulate cortex [ACC], orbitofrontal cortex, amygdala, and hippocampus).

We found regional brain volumes to account for small but significant amounts of the variance in self-reported temperament scores. Specifically, higher effortful control was associated with larger volume of the left orbitofrontal cortex and hippocampus. Higher negative affectivity was associated with smaller volume of the left dorsal paralimbic relative to limbic portion of the ACC. Higher affiliativeness was associated with larger volume of the right rostral/ventral limbic portion of the ACC. Affiliativeness and surgency also showed a number of female-specific associations, primarily involving the rostral/ventral ACC.

Our results provide support for a neuroanatomical basis for individual differences in temperament and have implications for understanding the neurobiological mechanisms underlying the development of a number of psychiatric disorders.