Toddlers' transitions on non-verbal false-belief tasks involving a novel location: A constructivist connectionist model

Some argue that children learn a Theory of Mind (ToM), the understanding that others have mental states, at around 3.5 years. This is evidenced by their transition from failure to success on verbal false-belief tasks, when they begin to verbally predict an actress will search for a toy where she falsely believes it to be, rather than in its actual location. However, nonverbal measures have recently been used to show that children in their second year of life may already have some understanding of others' false beliefs. We present a Sibling-Descendant Cascade-Correlation neural-network model of one study that found 25-month-old toddlers correctly anticipated an actress would search according to her false belief. Networks were trained on true- and false-belief search patterns, simulating toddlers' everyday experience with true and false beliefs, and then tested on nonverbal true- and false-belief tasks involving a novel location. Networks transitioned from incorrectly predicting true-belief searches in both true- and false-belief tasks to making correct predictions in both tasks. Our model thus (1) reproduced the transition that has been observed in older children and (2) generalized its learning to a novel location. The model can be used to refine our understanding of the transitions while again demonstrating the usefulness of SDCC as an algorithm for modeling cognitive development.