 The view that success on metacognitive opt-out tests is indicative of self-consciousness is not uncontroversial, however. For example, it has been suggested that the uncertainty response is indicative not of metacognitive uncertainty monitoring but rather of first-order, environmental judgements concerning a third category between the intended two (Kornell, Son, &amp; Terrace 2007; Hampton 2009; also see Carruthers 2008; Kornell 2014; Musholt 2015: ch. 7). On such an interpretation, the research on metacognition does not provide compelling evidence regarding self-consciousness in infants and non-human animals (but for critical discussion see J.D. Smith 2005; J.D. Smith, Couchman, &amp; Beran 2014; also relevant is the distinction between “evaluativist” and “attributivist” accounts of metacognition outlined by Proust (2013)). The question of the significance of opt-out tests for attributions of self-consciousness remains controversial.