Age-related changes in confusion between memories for thoughts and memories for speech.

The present experiments compared people's abilities to make decisions about the origin of their memories. Experiment 1 demonstrated that 6-year-olds were as good as 17-year-olds in discriminating memories originating from what they said earlier (self-generations) from memories of what another person said earlier (external presentations). However, in both experiments 1 and 2, 6-year-olds were not as good at discriminating what they had said earlier from what they had only thought. The possibility that younger children simply have more difficulty distinguishing between memories originating from the same class, internal or external, was ruled out because 6-year-olds performed as well as 9-year-olds when differentiating between memories from 2 external sources (experiment 2). Nor could their difficulty be attributed to a general problem in distinguishing memories for their thoughts from any other class of memories because they were at no disadvantage in discriminating their earlier thoughts (words they imagined themselves saying) from words someone else said (experiment 2). Our findings suggest that some distinctions, self versus other, emerge as cues in memory sooner than other distinctions, thoughts versus actions.