Cultural comparisons suggest that an understanding of other minds may develop sooner in independent versus interdependent settings, and vice versa for inhibitory control. From a western lens, this pattern might be considered paradoxical, since there is a robust positive relationship between theory of mind (ToM) and inhibitory control in western samples. In independent cultures, an emphasis on one's own mind offers a clear route to 'simulate' other minds, and inhibitory control may be required to set aside one's own perspective to represent the perspective of others. However, in interdependent cultures, social norms are considered the key catalyst for behaviour, and metacognitive reflection and/or suppression of one's own perspective may not be necessary. The cross-cultural generalizability of the western developmental route to ToM is therefore questionable. The current study used an age-matched cross-sectional sample to contrast 56 Japanese and 56 Scottish 3-6-year-old's metacognition, ToM and inhibitory control skills. We replicated the expected cultural patterns for ToM (Scotland>Japan) and inhibitory control (Japan>Scotland). Supporting western developmental enrichment theories, we find that inhibitory control and metacognition predict theory of mind competence in Scotland. However, these variables cannot be used to predict Japanese ToM. This confirms that individualistic mechanisms do not capture the developmental mechanism underlying ToM in Japan, highlighting a bias in our understanding of ToM development. RESEARCH HIGHLIGHTS: We replicate an independent cultural advantage for theory of mind (Scotland>Japan) and interdependent advantage for inhibitory control (Japan>Scotland). From a western lens, this pattern might be considered paradoxical, since there is a robust positive relationship between theory of mind and inhibitory control. Supporting western developmental enrichment theories, we find that the development of inhibitory control mediates the link between metacognition and theory of mind in Scotland. However, this model does not predict Japanese theory of mind, highlighting an individualistic bias in our mechanistic understanding of theory of mind development.