Multiple sources of competence underlying the comprehension of inconsistencies:
A developmental investigation.
Abstract:
How do children know the sentence the glass is empty and not empty is inconsistent? One
possibility is that they are sensitive to the formal structure of the sentences and know that a
proposition and its negation cannot be jointly true. Alternatively, they could represent the two
state of affairs referred to and realize that these are incommensurate . i.e., that a glass cannot
simultaneously be empty and contain something. In two studies we investigated how children
(N=186; ages 4 to 8) acquire competence to notice inconsistencies. We found that children could
determine that two states of affairs were incommensurate before being able to determine that
statements of the form p and not-p were inconsistent. Our results demonstrate that competence in
understanding inconsistent relations depends on (a) the ability to represent two states of affairs
and (b) the ability to process negation in the context of an inconsistency. We discuss these results
in relation to sources of competence that may underlie the assessment of such simple
inconsistencies.