In one of the first open diffusion experiments with young children, a tool-use task that afforded multiple methods to extract an enclosed reward and a child model habitually using one of these methods were introduced into different playgroups. Eighty-eight children, ranging in age from 2 years 8 months to 4 years 5 months, participated. Measures…

The processes behind the transition from consistently failing tests of false belief understanding to consistently passing the tests was investigated by tracking changes in children's mental state understanding. Participants were 42 children (aged 3;1 to 4;3). There were two conditions; an experimental condition in which children were tested on a…