>>12161596Cranial capacity has actually decreased over the last few tens of thousands of years. The prevailing hypothesis is that humans have domesticated themselves, resulting in smaller bodies overall (including brain size) but a greater propensity for cooperation. The same cranial decreases can be seen in other domesticated animals such as dogs, cows, and sheep. Turns out the resources needed for cooperative survival are cheaper than the resources needed for roughing it on your own, which should become fairly obvious if you're ever inclined to practice your survivalism skills yourself. There are a lot of required skills when you're on your own that you just don't actually need when you have enough buddies with you.
Now, the question of consciousness depends on how you define consciousness, but it isn't far-fetched to imagine that people were just as lucid as they are today but just didn't have access to information beyond their small communities of people. It's no surprise that agriculture and the written word were such game-changers if everyone was already capable of inputting and using the information.
