eLife assessment
This study provides useful findings regarding the capacity for mental state attribution on the Frith-Happé task in a highly social non-human primate species, the marmoset. The methods are solid, integrating validated brain imaging and eye-tracking techniques, however, the theoretical analysis is incomplete due to the omission of a "goal-directed condition." The inclusion of the goal-directed condition would enable a stronger interpretation of the findings and would be of broad interest to neuroscientists working in social and affective sciences.