Contents lists available at ScienceDirect Cognitive Development journal homepage: www.elsevier.com/locate/cogdev Links among parents’ mental state language, family socioeconomic status, and preschoolers’ theory of mind development ☆ Susanne Ebert a, ⁎ , Candida Peterson b , Virginia Slaughter b , Sabine Weinert a a Department of Psychology I, University of Bamberg, Germany b School of Psychology,University of Queensland, Australia ARTICLE INFO Keywords: Theory of mind Mental state talk Family socioeconomic status Parent-child interaction Longitudinal study Cross-cultural research ABSTRACT Individual differences in preschoolers’ theory of mind (ToM) development were studied in re- lation to parents’ preferences for using mental state language in conversations with their child in 121 German families from two different socioeconomic (SES) levels in a 3-phase longitudinal design. We also cross-sectionally tested 47 Australian mother-child dyads to explore similarities and differences to the German sample and to validate a shortened version of the Maternal Mentalistic Input Inventory (MMSII: Peterson & Slaughter, 2003). Results made a number of novel contributions. For the German sample SES contrasts in children’s ToM development were evident at all three longitudinal measurement points. Furthermore, results for the middle SES German and Australian groups replicated past studies in showing links between parents’ self- reported use of elaborated mentalistic conversation and children’s higher ToM scores. Additional longitudinal analyses for the German sample revealed contrasting effects of parents’ preferences for the use of elaborated versus simple non-elaborated mental state language according to SES. Lower SES German children gained ToM understanding at a faster rate from age 3 to age 5 when their parents showed a high preference for using non-elaborated mental state language. By contrast, in middle-class German families, a high preference for causally elaborated mental state language was positively linked with children’s developmental path of ToM. These associations between parental conversational style and children’s ToM varying with SES were discussed in terms of their implications both for developmental theory and for future research. 1. Introduction A mother who is a university professor and a mother who is a shop assistant are each talking to their four-year-old child about how best to surprise Dad for his birthday. Will they differ in how they frame their discussions of the birthday surprise? If so, do these differences in their talk interconnect with differences in their children’s development of an understanding of others’ minds, including internal, non-visible mental phenomena like surprises, thoughts or beliefs? http://dx.doi.org/10.1016/j.cogdev.2017.08.005 Received 2 June 2016; Received in revised form 7 August 2017; Accepted 7 August 2017 ☆ Part of this study was supported by grants from the German Research Foundation (DFG) to the Developmental Subproject (Principal Investigator: Sabine Weinert; Grant WE 1478/4-1 & 4-2) of the Research Group “BiKS” (“Bildungsprozesse, Kompetenzentwicklung und Selektionsentscheidungen im Vorschul- und Grundschulalter; English:” Educational Processes, Competence Development, and Selection Decisions in Preschool and School-age Children) at the University of Bamberg. ⁎ Corresponding author at: Department of Psychology I, University of Bamberg, Markusplatz 3, 96047 Bamberg, Germany E-mail address: susanne.ebert@uni-bamberg.de (S. Ebert). Cognitive Development 44 (2017) 32–48 0885-2014/ © 2017 Elsevier Inc. All rights reserved. MARK