There's a tradeoff between accuracy and speed. For survival reasons the brain needed to evolve to make both quick decisions and well thought decisions. If a p

There's a tradeoff between accuracy and speed. For survival reasons the brain needed to evolve to make both quick decisions and well thought decisions. If a predator appears in front of you you might not be able to give a lot of thinking to the decision of what you need to do. If you are a nomad during the ice age and you need to collect food and prepare a shelter, or track a prey for long distances, you probably need to give it some thought.