Randall points me to a paper, Brain Regions for Perceiving and Reasoning About Other People in School-Aged Children:
Neuroimaging studies with adults have identified cortical regions recruited when people think about other people’s thoughts (theory of mind): temporo-parietal junction, posterior cingulate, and medial prefrontal cortex. These same regions were recruited in 13 children aged 6â€“11 years when they listened to sections of a story describing a character’s thoughts compared to sections of the same story that described the physical context. A distinct region in the posterior superior temporal sulcus was implicated in the perception of biological motion. Change in response selectivity with age was observed in just one region. The right temporoâ€“parietal junction was recruited equally for mental and physical facts about people in younger children, but only for mental facts in older children.
The sample included 7 girls and 6 boys. No mention of sex differences. Though perhaps the methods were too coarse. In any case, aspiring neuroimagers of social intelligence just need to go to a Perl Mongers meeting to recruit cognitive outliers!