This is just another one of those speculative stories invented out of thin air that are supposed to be plausible just because they illustrate some reproductive

This is just another one of those speculative stories invented out of thin air that are supposed to be plausible just because they illustrate some reproductive advantage of one trait over another and are hence deemed to be "evolutionary", and hence to be somehow "scientific". It is an easy trap to fall into after learning a little about evolution, but it is a rather bad thinking pattern. There are hundreds of similar stories one can make up for why the eyes, for example, evolved the way they did and likely all of those just invented at will will be false, while sounding similarly "evolutionary", since almost any complex trait is a product of a whole series of mutations, some of which might not have a single nice intuitive interpretation at all, and those are changes in terms of proteins produced, not necessarily easily translatable into changes in high-level traits. For one, in the case you describe, it could just as well be an accidental byproduct of a series of other small adaptations that were beneficial in other ways. It could have been hundred of ways, we have no clue. So, please don't bring up evolution when there is absolutely no evidence to base upon. Especially in case of the brain, which we barely understand at all, and which additionally as a soft tissue decays fast and hence even its anatomical evolution is almost impossible to trace back, what to speak about translating this into some sort of cognitive history of human beings.