Humans have scalp hair. But why is human scalp hair so varied? Biological anthropologist Tina Lasisi wanted to find out. And while completing her PhD at Penn State University, she developed a better system for describing hair — rooted in actual science. (Encore)To hear more from Tina, check out these webinars: Why Care About Hair (https://bit.ly/3liJZ96) and How Hair Reveals the Futility of Race Categories (https://s.si.edu/3Dik6g8). And to dive deep into Tina's research, we recommend her paper, The constraints of racialization: How classification and valuation hinder scientific research on human variation (https://bit.ly/3DfDrOS).