In contemporary philosophy and psychology there is an ongoing debate about Theory of Mind (ToM), which mainly concerns our ability to understand other people. For almost two decades, authors have argued in favour of a crucial relationship between language and children’s development of ToM. Studies based on verbal tasks suggest that children possess a ToM not earlier than about the age of four. Nevertheless, in recent years, this paradigm has been almost replaced by a ‘new’ nativist paradigm conceiving of mental capacities as part of our purely biological inheritance. In contrast with the traditional tasks, non-verbal task results indicate that children possess ToM at the age of 15 months, or earlier. The contradictory data led to the so-called ‘developmental gap’: how is it that 15-month-olds already possess ToM, while failing the traditional tasks until the age of four? My thesis is that the data at our disposal, if interpreted in the light of a suitable theoretical framework, do not generate a genuine contradiction. Prior to the interpretation of the research results, a distinction between epistemological and metaphysical levels of investigation, and a clear analysis of notions such as ‘representation’, ‘inference’, ‘mental state’, and the like, is required.