Heyes argues that human metacognitive strategies (“cognitive gadgets” or “mills”) are the products of cultural evolution based on domain‐general cognition with few simple biases. Although like Heyes, we believe that the evolution of domain‐general cognitive processes played a crucial role in the evolution of human cognition, we argue that Heyes' distinction between mills and grist is too sharp, that associative learning evolved gradually to become more complex and hierarchical, something that is not captured by the system 1/system 2 distinction, and (...) that human cognitive plasticity required the genetic accommodation of gadget‐specific processes that led to more plasticity‐enhancing human‐specific biases. (shrink)