Want that is understood well before say that, think that, and false belief: a test of de Villiers's linguistic determinism on German-speaking children.

Two experiments with 79 monolingual German speaking children between 2.5 and 4.5 years showed a consistent developmental gap between children's memory/inference of what someone wanted and what someone wrongly said or thought. For instance, when John is still playing and mother says, "John should be going to bed," more than 70% answered correctly that mother wanted John to go to bed. However, when mother said, "John is going to bed," about 70% answered wrongly that she thought/said that he was still playing. Correct answers emerged with the mastery of the false-belief task. In German, want sentences (about something to happen) obligatorily take the same grammatical that complement as say or think sentences. Therefore, the observed gap constrains de Villier's (1995) linguistic determinism, which claims that acquisition of the necessary grammatical structures for talking about the mind drives children's ability to think about the mind.