We talk to neuroscientist Lisa Feldman Barrett about why the idea that you have a lizard brain and a rational brain is completely wrong, how you can fight against implicit biases by swamping your brain with new data, why your brain’s most important job isn’t actually to think or be rational, and about one time Carl Sagan was very wrong about how brains work. Her most recent books are How Emotions Are Made: The Secret Life of the Brain and Seven and a Half Lessons About the Brain.