We investigated cultural influences on young children’s acquisition of social-cognitive concepts. A theory of mind (ToM) scale (Wellman & Liu, 2004) was given to 129 children (71 boys, 58 girls) ranging in age from 3 years 0 months to 7 years 10 months. The children were from three distinct cultural groups: (a) trash pickers ( pemulung) living a subsistence lifestyle in Jakarta, Indonesia; (b) middle-class Jakartans living and attending preschools within 5 km of the pemulung group; and (c) middle-class Australians. All children were individually tested in their native language. Cross-group comparisons revealed no significant differences among the three groups in mastery of false belief (the traditional ToM indicator), despite their widely different socio-economic circumstances. However, the pemulung children were slower than the two middle-class groups in mastering two other ToM concepts, namely knowledge access and emotion concealment. These findings shed new light on patterns of cross-cultural consistency in false-belief mastery, as well as revealing cross-cultural variation in other ToM concepts that plausibly reflect variation in children’s everyday life circumstances.