Contrasting one's share of the shared life space: Comparing the roles of metacognition and inhibitory control in the development of theory of mind among Scottish and Japanese children

Cultural comparisons suggest that an understanding of other minds may develop sooner in the independent settings, whereas inhibitory control may develop sooner in interdependent settings. 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 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 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- to 6-year-old’s metacognition, ToM and inhibitory control skills. In contrast to the individualistic perspective dominant in Scotland, in Japan, the word for self, jibun, translates as "one's share of the shared life space". We replicated the expected cultural advantages for ToM (Scotland > Japan) and inhibitory control (Japan > Scotland). Following the predictions of simulation theory, 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 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.