 Another body of research pertaining to the question of self-consciousness in infants and non-human animals is the work on metacognition (and metamemory). The term “metacognition” typically refers to the capacity to monitor and control one’s own cognitive states, and is manifest in one’s judgements (or feelings) concerning one’s own learning and consequent level of certainty or confidence (J.D. Smith 2009; Beran et al. 2012; Proust 2013; Fleming &amp; Frith 2014). The suggestion is that if a creature is able to monitor their own level of confidence, they are to that extent self-conscious. One common paradigm for testing metacognitive abilities involves presenting subjects with a stimulus that they must categorise in one of two ways. Crucially, they are also given the opportunity to opt out of the test, with correct categorisation resulting in the highest reward, opting out resulting in a lower reward, and incorrect categorisation resulting in no reward. The assumption is that the opt-out response reflects a meta-cognitive judgement of uncertainty. Evidence gathered from such a paradigm has been taken to show metacognitive abilities in some birds (Fujita et. al. 2012), dolphins (J.D. Smith et. al. 1995), primates (Shields et. al. 1997), and children from the age of around 4 years (Sodian et. al. 2012).