Perhaps the most logical explanation is that people don't have to be as smart as they were when computers, the internet and DIY "recipes" are so readily availab

Perhaps the most logical explanation is that people don't have to be as smart as they were when computers, the internet and DIY "recipes" are so readily available. Even using a paper map is obsolete when a smart phone can verbally direct you. How many people do math by hand now? Example: California native Americans (Chumash) did not have to be smart. Every day was a great day, food and water were everywhere from the ocean to the valleys whereas in south America things were more difficult. Spaniards were stunned by the Aztec capital being larger and more advanced than anything in Europe. The Aztecs had astronomy, math, and domesticated turkeys for food. They created all that because they had too. Food in Mesoamerica: http://tlmorganfield.com/food-mesoamerica-domesticated-food-animals/ http://tlmorganfield.com/food-mesoamerica-domesticated-food-... Aztec capital, Tenochtitlan: https://www.livescience.com/34660-tenochtitlan.html https://www.livescience.com/34660-tenochtitlan.html