The lifespan in the U.S. has in recent decades been shortening after decades of increasing. This is due to misconceptions about what a healthy diet is and partly due to our health regulations that require vaccinations. It is also partly due to the ubiquitous sugar and white flour that feed cancer, cause diabetes, pack fat on one's body and ruin one's health. We also see in Unit 10 how to defeat old age and its maladies with stem cell therapy. People can now increase their life spans significantly while being healthier.
The brain differentiates humans from the other mammals because it allows complex language, concepts and reasoning that led to civilization and knowledge. The brain is a complex bio-computer whose functions allow humans to build and maintain cultures, civilizations, knowledge, machines, medicines, schools and health.