Response or Comment
Carruthers argues that an integrated faculty of metarepresentation evolved for mindreading and was later exapted for metacognition. A more consistent application of his approach would regard metarepresentation in mindreading with the same skeptical rigor, concluding that the "faculty" may have been entirely exapted. Given this result, the usefulness of Carruthers’ line-drawing exercise is called into question.
Buckner, Cameron; Shriver, Adam; Crowley, Stephen; and Allen, Colin. (2009). "How "Weak" Mindreaders Inherited the Earth". Behavioral and Brain Sciences, 32140-141. http://dx.doi.org/10.1017/S0140525X09000570