Language promotes false-belief understanding: evidence from learners of a new sign language.
Developmental studies have identified a strong correlation in the timing of language development and false-belief understanding. However, the nature of this relationship remains unresolved. Does language promote false-belief understanding, or does it merely facilitate development that could occur independently, albeit on a delayed timescale? We examined language development and false-belief understanding in deaf learners of an emerging sign language in Nicaragua. The use of mental-state vocabulary and performance on a low-verbal false-belief task were assessed, over 2 years, in adult and adolescent users of Nicaraguan Sign Language. Results show that those adults who acquired a nascent form of the language during childhood produce few mental-state signs and fail to exhibit false-belief understanding. Furthermore, those whose language developed over the period of the study correspondingly developed in false-belief understanding. Thus, language learning, over and above social experience, drives the development of a mature theory of mind.
Pyers
Jennie E
JE
Department of Psychology, Wellesley College, 106 Central St., SCI480, Wellesley, MA 02841, USA. jpyers@wellesley.edu
Senghas
Ann
A
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D015331:Cohort Studies; D032882:Comprehension / Q000502:physiology*; D003210:Concept Formation / Q000502:physiology; D003423:Critical Period, Psychological; D003638:Deafness / Q000534:rehabilitation; D008192:Deception; D006801:Humans; D007804:Language Development; D007858:Learning / Q000502:physiology*; D008137:Longitudinal Studies; D009527:Nicaragua; D018187:Personal Construct Theory; D012813:Sign Language; D013647:Task Performance and Analysis; D056345:Theory of Mind / Q000502:physiology; D055815:Young Adult