Proceedings of the Annual Meeting of the Cognitive Science Society

A central canon in theory of mind research is that between theages of three and four a drastic performance difference inchildren’s understanding occurs. However, the reason for the‘three to four shift’ has yet to be settled. One account, Theoryof Mind Mechanism (ToMM) theory (Leslie, 1994), posits thatchange in inhibitory power can account for this difference. Thisis supported by a recent computational implementation of thetheory, showing that differences in inhibitory power canaccount for age differences at an aggregate level (Wang,Hemmer, & Leslie, 2019). However, as Baker et al. (2016)point out, established findings are entirely based on group-aggregated findings, yet computational and developmentalprocesses do not take place in the ‘aggregated mind’. Whatremains largely unexplored is what happens at the level of theindividual child. Here we combine the computationalimplementation of ToMM with data from Baker et al., 2016,who assessed longitudinal developmental change in Theory ofMind performance by repeated testing of individual child overthe three-to-four shift period on standard ‘Sally and Anne’ falsebelief tasks, to obtain a cumulative record for each child.Specifically, we found that children’s age was not directlyinformative of developmental change in theory of mindreasoning. Instead, the main contributor to theory of mindperformance at the individual learner level is inhibitory power.