A main source for the ages
Sequential Progressions in a Theory-of-Mind Scale: Longitudinal Perspectives
Henry M. Wellman, Fang Fuxi, Candida C. Peterson · 2011 · Child Development
- Children
- About 400 children
- Where
- The United States, Australia and China
- Ages
- About 3 to 6 years
- How
- Researchers tested children with five short story tasks
- What it found
- Children learned these ideas in the same order. Children whose only success was knowing that people like different things were about 3½ on average; those who also understood untrue beliefs were about 5.
- Limits
- These are average ages of children at each step, not the age when half of children get there. It pools earlier studies by the same research group.