According to a group of anthropologists headed by Dr Brian Hare of Duke University, a decline in testosterone levels about 50,000 years ago led to the development of advanced tools and art. Technological innovation, making art and rapid cultural exchange came at the same time that Homo sapiens developed a more cooperative temperament, the scientists say. Image credit: Tyler B. Tretsven. There are a lot of theories about why, after 150,000 years of...
