Nicholas A. Christakis is a professor and director of the Human Nature Lab at Harvard University. He conducts research at the intersection of the natural and social sciences, in the field of biosocial science. Christakis’s work examines the emergence of cooperation and innovation in human social networks, the genetic determinants of network structure, and the evolutionary biology of networks. This year, in Nature, his lab reported the mapping of the networks of Tanzania’s Hadza hunter gatherers. He is the co-author of the 2011 book Connected. In 2006, Christakis was elected to the National Academy of Science’s Institute of Medicine and in 2010 was made a fellow by the American Association for the Advancement of Science. In 2009, he was on the TIME 100 list of most influential people.