A surge in human brain size that occurred roughly 1.8 million years ago can be directly linked to the innovation of cooking. Cooking is the secret to our success!
Humans have, on average, 86 billion neurons in the brain, 16 billion of which are in the cerebral cortex. The cerebral cortex is responsible for functions such as awareness and logical and abstract reasoning, hence humans’ remarkable cognitive abilities. With 86 billion neurons, humans should have to spend over nine hours per day every single day eating. How do we do it? By cooking! To cook is to use fire to pre-digest foods outside of the body, which allows humans to spend time doing much more interesting things with our neurons besides constantly searching for and eating food.