Using new methods to analyze stone projectile points crafted by North America’s earliest human inhabitants, Smithsonian scientists have found that these tools show evidence of a shift toward more experimentation in their production beginning about 12,500 years ago, following hundreds of years of consistent stone-tool production created using uniform techniques. The findings provide clues into changes in social interactions during a time when people are thought to have been spreading into new parts of North America and adapting to different environments, beginning a period of cultural diversification.