It is difficult to see how such innovations could have been missed if general problem solving abilities rather than domain specific ones were part of the cognitive skills of premodern industrial people. The more likely situation is that they were not, and that such skills have only developed in modern people, through the influence of such factors as modern schooling. One can accordingly conclude that general domain independent solving abilities found in modern people are unlikely to be relevant to understanding human origins, as they are a modern and not an ancient mental phenomena. Overskeid argues some specific points against the idea that expertise capacity was responsible for expanding the human brain. While Overskeid is right to point out that expertise is not a general ability, he is wrong to suggest that those 50,000 chunks of knowledge could not create the skills needed for the survival of our early hunter-gatherer ancestors.
Expertise can be as general or as narrow as the problem space in which it is developed.
But over a ten year minimum period of apprenticeship in the skills necessary for survival through simple hunter-gathering, early hominids would have been exposed to a wide variety of seasonal and annual climatic variations. This would have provided them with the generality needed for future survival. Contrary to Overskeid's view, this skill is not acquired for a stable environment. In December, for example, the land dries, and water holes become empty. It is difficult, however, to separate abstract factual knowledge from domain factual knowledge acquired from expertise.