Foragers and Farmers
Knowledge accumulates throughout generations. It travels through time as long as there is always someone at the other end of the arrow of time to absorb it, assimilate it and apply it. Language helped it transcend --first in oral traditions , then in written form. Sure, there were some instances of miscommunication between some generations and knowledge stalled at times, but generally speaking, knowledge compounds itself. It exhibits the same exponential behavior as wealth. For early forager humans, the knowledge to conquer our environment (learning about medicine plants, edible roots, game migrating patters) was as valuable then as it is today to learn what's the next meme stock being hyped on reddit. At the beginning the band forager culture fomented cooperation. To share what early foragers gathered/hunted was the rational thing to do. After all, the volatility of your returns (one day you'd have a good kill, but then days would go by without a catch) pushed you to share w