Griots were a combination of advisors, historians, and entertainers charged with preserving rich oral traditions for future generations.
The first great boom in the West was spurred by: c. mining
This came from their discovery of silver and gold.
Providing harsh criticism to other players is a natural part of being a good leader - this is true. The reason for this is that good leaders will often be able to accept a harsh critique coming their way and also be able to give a harsh critique which a player deserves.