The purpose of this talk is to argue for the possibility that embodied expressions of confidence reflect deeply plausible candidates for bridging the gap between a highly prominent phylogenetic origin story about capacities for self-knowledge (i.e. evaluative metacognition, cf. Proust 2013) and a prominent ontogenetic origin story about the same (i.e. mindreading from the social-scaffolding viewpoint, cf. Vygotsky 1934/1978; Heyes et al. 2020). The chief concern in the debate over metacognition is whether the evaluative species of metacognition lays the cognitive foundation for the metarepresentational species, commonly referred to as 'mindreading' (Proust 2009, 2012, 2013, 2015; Carruthers 2016, 2017, 2020). Specifically, the debate is about whether the cognitive systems of non-human animals that perform well in the so-called ‘uncertainty monitoring paradigm’ (e.g. Smith et al. 1995; Shields et al. 1997; Smith et al. 2003, 2006, 2008, 2012, 2013, 2014, 2018, 2019) and the like (e.g. Roberts et al. 2012; Iwasaki et al. 2013) possess significant phylogenetic cognitive ingredients to distinctly human capacities for acquiring self-knowledge. The deeper philosophical question is whether theories that appeal to mechanisms for monitoring, evaluating, predicting, and controlling cognitive processes might ever satisfactorily explain the origin of capacities for acquiring beliefs about the self qua beliefs about the self, i.e. theories based on the Bayesian Brain Hypothesis (Knill and Pouget 2004; Chater et al. 2010; Meyniel et al. 2015a; Hu et al. 2021) and the predicative processing framework (e.g. Friston and Stefan 2009; Clark 2013, 2015, 2016; Hohwy 2013, 2020). In this talk, I claim that Bayesian theories of metacognition (e.g. Meyniel et al. 2015a, 2015b; Hu et al. 2021) have the tools to explain the origin of distinctly human capacities for self-knowledge, but such an explanation demands an appeal to embodied cognition (cf. Clark 1999; Wilson 2002; Seth 2013; Wong 2018; Shapiro 2019), specifically embodied expressions of confidence (and uncertainty), which are particularly well-suited to explain the phylogenetic origin of self-knowledge, so long as the social-scaffolding view is on the right track to explain its ontogenetic origin.