Anthropologist Tom Pearson was devastated after his daughter Michaela was diagnosed with Down syndrome. When he began to examine that emotional response, he found himself wrestling with questions that have roiled his field for decades. Early anthropologists would often compare people of different backgrounds and abilities, asking questions like: How is one group different from another? Which one is stronger or smarter? And how do we understand people who don’t fit our expectations? This week, we talk with Pearson about his family’s story, and the evolution of our thinking on disability and difference.