Our ancestors had large brains and made tools and fire long before language or representational art. Some structural change enabled that. Probably, there were i

Our ancestors had large brains and made tools and fire long before language or representational art. Some structural change enabled that. Probably, there were individual components of it that arose before the whole change happened, and then some further time for it to spread through the population and then leave artefacts. The spread may have been dramatic, because to an individual who could think, everyone else might seem like zombies or animals, easily manipulated or outwitted. How some "woke" Holdenesque teenagers feel themselves to be. My point is that, maybe such a large brain isn't really necessary for intelligence. Just the structural change. Although, since we're the only ones, sufficient processing power seems a necessary precondition. It's just not clear how much. Perhaps parrots are quite close. There's the encephalization quotient, which finds the ratio between brain and body size is what's important. e.g. Whales have enormous brains, but dolphins seem to be more intelligent. Parrots, needing to be light enough to fly, have a high EQ. (Spiders too) Aside: it's thought that human brain size is limited by the birth canal, and we are born prematurely, with swaddling and cots etc being artificial wombs. Bird nests are also artificial wombs.