In lecturers and training on adolescent development I often discuss the emergence of empathy during puberty. Now research has caught the development of these higher thinking processes using brain scans and young people playing games dependent on reciprocity. For the study, participants between nine and 23-years old took part in an ultimatum game based on the exchange of money. Proposers first selected between two different divisions of $10, and responders then decided whether to accept or reject the chosen division. Researchers evaluated how participants used two different cognitive strategies when making their decision using computational modeling, and then investigated how these processes correlated with measurements of participants’ cortical thickness, as obtained through magnetic resonance imaging (MRI).
Younger players tended to want to minimize the difference in the division of the money, whereby everyone gets the same amount but as players became older, they were more inclined to consider the other player’s intentions. This shift from a simple rule-based egalitarian strategy to a more sophisticated strategy that considers both the other player’s intentions and notions of reciprocity, was observed during late adolescence. This gradual shift coincided with cortical thinning in the brain, specifically, in areas of the dorsomedial prefrontal cortex, which is involved with how we view others’ mental states, and posterior temporal cortex, which is involved in visual perception particularly in processing facial information.