James Arthur Lecture: How our Energy-Hungry Brains Shaped the Evolution of Human Childhood

What about young kids, whose brains are bigger in proportion to their bodies and who are also learning so rapidly? In this engaging lecture, Harvard Professor Chris Kuzawa will take us on a fascinating journey to uncover the "caloric price tag" of our uniquely complex brains and the way we learn.

Professor Kuzawa and his team have discovered some surprising truths about when our brains dominate our body’s energy budgets. It's not when we're newborns, even though babies have such large heads compared to their bodies. Instead, it's during childhood, when the brain is buzzing with activity as kids learn at lightning speed. These energy demands are so high that they outpace the energy that 5-year-olds expend on physical activity, and they account for an amazing two-thirds of the body’s energy use at rest, which is a large enough caloric drain to influence how we grow. As the brain's energy needs peak, the body's growth slows down— with growth and learning trading off for resources over time as kids get older. Indeed, our hungry brains help explain why our children grow at a pace more typical of a cold-blooded reptile than a warm-blooded mammal!

These findings offer new glimpses into human evolution, including insights into how our ancestors evolved our energy-intensive form of thinking and learning. A key piece of this puzzle was the development of uniquely human strategies for childcare, like sharing food and raising children cooperatively, which helped meet our developing brains’ high energy needs. Because the brain dominates the body’s use of energy in childhood, this work is also providing new insights into contemporary societal and health issues, including nutritional needs during the school years, and patterns of weight gain and body composition. Don't miss this opportunity to learn about the incredible journey of our brain's evolution and its impact on our lives today.