Explicit metacognition at age 3

Metacognition – the capacity to represent and reflect upon our knowledge and its sources – is fundamental for all forms of higher cognition and learning. Yet, a vast body of developmental research has suggested that metacognition emerges surprisingly late. This research was mainly built on the assumption that metacognition is optimized for individual reflection and decision-making and has thus tested children’s competence in individual settings. In contrast, recent theoretical approaches have argued that the core function of metacognition is social: Metacognition is primarily for communicating one’s own (un-)certainty towards others in the service of joint coordination. Building on these approaches, we tested young children’s metacognitive competence in socio-communicative rather than individual settings. In a cooperative game, 3- and 5-year-old children were asked by a partner to help them determine the contents of a container. Depending on condition, children had either full or only partial knowledge about the contents. Across three preregistered studies (N = 162), already 3-year-old children demonstrated metacognitive competence. In their advice-giving, children spontaneously and explicitly expressed their uncertainty when they were ignorant but did not do so when they were knowledgeable. These findings are in line with the idea that metacognition is primarily a socio-cognitive capacity and challenge standard interpretations of its protracted development.