Abstract
There is growing acceptance among language evolution researchers that an increase in our ancestors’ theory of mind capacities was critical to the origins of language. However, little attention has been paid to the question of how those capacities were in fact upgraded. This article develops a novel hypothesis, grounded in contemporary cognitive neuroscience, on which our theory of mind capacities improved as a result of an increase in our System-2 thinking capacities, in turn based in an increase in our working memory capacities. I contrast this hypothesis with what would appear to be the default position among language evolution researchers, namely, that our theory of mind became more powerful as a result of genetic change to a domain-specific mindreading system which we share with other great apes. While the latter hypothesis is not implausible, it arguably enjoys less empirical support at present than does the alternative hypothesis I develop.