Exploring the Relationship Between Mental-State Language and Children’s Early Vocabulary Development

• In Event: Poster Session 02
  In Poster Session: PS 02 Topic - Social Cognition

Abstract

Infants’ exposure to mental-state language is related to social-communicative skills that impact later language development and to infants’ acquisition of mental-state words. Mothers’ referencing of 6- and 9-month-old infants’ mental states predicts infants’ joint attention (Roberts et al., 2013) and gesture use (Slaughter et al., 2008), while these social-communicative skills are linked to later language development (Iverson & Goldin-Meadow, 2005). Mothers’ production of mental-state terms with their 2-year-olds is also related to toddlers’ production of mental-state terms at 3 years (Furrow et al., 1992). The current study explored whether mothers’ mental-state language to their 5-month-olds is related to the child’s mental-state language and vocabulary score at 24 months.
Mothers and their 5-month-old infants (n=31) engaged in a 3-min free play lab session. Mothers’ language referencing infants’ internal states was coded by two blind raters (Cohen’s kappa =0.79). The mental-state categories included references to infant emotions, physiology, perception, intentional agency, desire, belief, and attention-cognitive processes (Roberts et al., 2013). Mothers completed the MacArthur-Bates Communicative Development Inventory (CDI) Words and Sentences when their children were 24 months. The CDI vocabulary list contains 12 mental-state words from three categories; emotion, desire, and belief. Using the method reported by Brooks & Meltzoff (2014), the number of mental-state words were compiled into a child mental-state score.
The number of mental-state terms produced by each mother was examined relative to the child’s mental-state score and the CDI vocabulary (total words produced). The scatterplot of these data showed no evidence of correlations between mothers’ mental-state language and child scores. Mothers’ mental-state language to infants increases significantly between 13 and 28 months of age (Beeghly, Bretherton, & Mervis, 1986); the amount of maternal mental-state language at 5 months is likely much less frequent and thus less likely to directly impact 24-month language scores.
A second focus of this study examined the relation between 24-month vocabulary scores and child mental-state scores; prior research reported toddlers begin producing desire terms between 18 and 24 months (Bartsch & Wellman, 1995) and that children’s first internal-state words were preceded by a rapid increase in vocabulary (Lamb, 1991). A significant relationship was found between the child mental-state score and 24-month-vocabulary (Spearman rank-order correlation ρ=0.825, p<.001). To examine if the type of mental-state term was related to vocabulary size, vocabulary scores were divided into quartiles, and the number of emotion words vs. belief-desire words were examined in each quartile. Children in the first vocabulary quartile produced emotion words only (e.g., love, happy, like). Those in the 2nd and 3rd quartiles produced on average .94 of 5 belief-desire words (e.g., need, want). Only children in the 4th quartile produced more than 2 of 5 belief-desire words, (M= 3.33). The smaller proportion of belief-desire words relative to emotion words parallels the ratios of these two categories reported for 28-month (Bretherton & Beeghly, 1982) and 32-month-olds (Poulin-Dubois et al., 2009). Taken together, these findings add to literature examining the developmental trajectory of mental-state language.

Authors

• Abigail Roberts, University of Texas at Dallas
  Non-Presenting Author

• Samia Razvi, University of Texas at Dallas
  Presenting Author

• Sarah Rehman, University of Texas at Dallas
  Non-Presenting Author

• Madeline Hale, University of Texas at Dallas
  Non-Presenting Author

• Meg Mickelsen, University of Texas at Dallas
  Non-Presenting Author

• Ginni Strehle, University of Texas at Dallas
  Non-Presenting Author

• Kaitlin Lawler, University of Texas at Dallas
  Non-Presenting Author

• Melanie J Spence, UT Dallas
  Non-Presenting Author