Language Promotes False-Belief Understanding

Abstract

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.The capacity to infer other people's mental states, and to use this information to predict behavior, is a central cognitive ability that emerges early in human development. By the age of 2, children demonstrate some implicit understanding of what others believe (Clements & Perner, 1994;Onishi & Baillargeon, 2005;Southgate & Csibra, 2007;Surian, Caldi, & Sperber, 2007), yet they do not reliably use such understanding to explicitly predict others' behavior until 2 years later (Wellman, Cross, & Watson, 2001). Indeed, some researchers have proposed that an explicit understanding of others' false beliefs requires particular linguistic experience (Milligan, Astington, & Dack, 2007;Perner & Ruffman, 2005). If so, what would happen if the relevant language exposure were unavailable until adulthood? Can other life experience support the representation of false belief?Previous studies have found that the timing of false-belief understanding depends on language in both typically developing and language-delayed children (for a review, see Milligan et al., 2007). However, in this research, language development and life experience have necessarily been conflated; both correlate with educational experience, socioeconomic status, and, most critically, age. Consequently, the nature of the link between language and false-belief understanding remains unresolved. Are particular language milestones prerequisite for false-belief understanding, or do language abilities merely facilitate the development of a theory of mind, a domain of cognition that could mature independently, albeit on a delayed timescale? We examined these questions with a population of adults with minimal language exposure during childhood. Because Nicaraguan Sign Language (NSL) emerged only recently, deaf Nicaraguan adults provide a natural opportunity to disentangle language exposure and life experience. NSL first appeared in the 1970s among deaf children entering special-education schools (Kegl, Senghas, & Coppola, 1999;Po...

Visible Social Interactions Do Not Support the Development of False Belief Understanding in the Absence of Linguistic Input: Evidence from Deaf Adult Homesigners

“…Our results also replicate the results of Pyers (2005), who employed (and innovated) the minimal-language, minimal-communication Experiential False Belief task with signers of NSL from Cohorts 1 and 2. In fact, 5 of the 6 Cohort 1 signers in the current study were the same individuals tested by Pyers (2005).…”

“…In order to minimize effects of having a shared language and/or educational experiences (such as those found when using picture-completion tasks), we employed an experiential False Belief task developed by Pyers (2005). Instead of conveying a narrative using language, or relying on literacy conventions, this methodology uses the participant’s own personal experiences in the course of the task to establish the false belief situation ( Experience Phase ).…”

Thinking about seeing: Perceptual sources of knowledge are encoded in the theory of mind brain regions of sighted and blind adults

“…In general, children acquire much of their knowledge of the invisible causal structure of the world through testimony (Harris, 2002a; 2002b; Harris & Koenig, 2006; Koenig, Clément, & Harris, 2004). Language and testimony are a particularly powerful tool for learning about the invisible contents of other minds (Bedny & Saxe, 2012; Robinson & Whitcombe, 2003; Robinson, Haigh, & Nurmsoo, 2008; Urwin, 1983); the absence of linguistic access to other minds can significantly delay theory of mind development, for example in deaf children born to non-signing parents (Figueras-Costa & Harris, 2001; Meristo et al, 2007; de Villiers, 2005; Moeller & Schick, 2006; Peterson & Wellman, 2010; Peterson & Siegal, 1999; Pyers & Senghas, 2009; Schick, de Villiers, de Villiers, & Hoffmeister, 2007; Woolfe & Want, 2002). In contrast, conversational access seems to give blind children a detailed representation of visual mental states, and the inferences they afford.…”

The emergence of temporal language in Nicaraguan Sign Language

“…Other early-emerging elements of the language used by the first cohort of signers include words for cardinal numbers, a distinction between the syntactic categories for nouns and verbs, and devices for indicating argument structure (Flaherty & Senghas, 2011; Flaherty & Goldin-Meadow, personal communication; Senghas, Coppola, Newport, & Supalla, 1997). With the appearance of the second cohort there emerged systematic ways of describing spatial relations ( to the right of, to the left of ), using spatial morphological marking to indicate the roles of the patient and recipient in an event, and language to express mental states (Pyers & Senghas, 2009; Pyers et al, 2010; Senghas, 2003). …”