This allowed us to cooperate in large numbers (more than the ~150 natural limit for a tribe). The Agricultural Revolution (12,000 years ago):
Build enough Hay Beds for every tribe member immediately. Sleeping on the ground makes them unhappy and unproductive. Sapiens
"History's Biggest Fraud." Humans stopped foraging and started farming. This allowed us to cooperate in large numbers
Keep an eye on your tribe's "Happiness" and "Health" bars. If they are too cold or hungry, they will stop working. they will stop working.