Children's Understanding of Logical Inconsistency

Five experiments involving 245 participants examined children's understanding of logical consistency. For instance, a character said that a man was both tall and very short. Only by 6 years of age did children show any understanding of logical inconsistency. This occurred despite: (1) good memory for the characters' claims; (2) the use of three different question forms including whether a person had made sense, said something silly, or whether both things a person said could be right; (3) the ability to identify other types of statements (e.g., factual inconsistencies) as not making sense; (4) the ability to compare and contrast the characters' claims in other ways; and (5) attempts to deepen children's processing of the claims by asking them to draw what each character said. Similar to false belief understanding, there was a monotonic relation between the number of older siblings a child had and logical consistency understanding on one of the tasks. It is argued that children may fail the different consistency tasks because of both logical factors (e.g., insufficient insight into logical necessity) and nonlogical factors tied to their social knowledge or insight into representation.