My current academic focus is on analyzing the processes of human social change—the continuities and recurring challenges in the social order from the rise of Homo sapiens and the creation of language through present day. I examine these processes through many lenses, including the rise of language, community, group behavior, social institutions, and biology.
Below is a timeline showing the evolution of my thinking and research, starting with my most recent work and dating back to my graduate studies:
- In 2020, I published three books and several articles on the human system: History of Humanity, Methods for Human History, the third edition of Migration in World History, as well as articles on human migration. Based on these insights, I began a new set of articles on early and recent human history; I also returned to earlier work in economic history and African population history.
- From 2016–2018, the collaborative study in world history of science was completed with three edited volumes, on the periods 1700–1850, 1000–1800, and life sciences after 1940. These showed the value of linking world history and history of science.
- In 2014, the various threads of my research and thinking began to intertwine and send me in a new direction. I broke away from the textbook’s long narrative of world history and turned toward developing a concise theory for world history. This was the beginning of exploring the idea of a human system. Also in 2014, I was elected to the presidency of the American Historical Association; my year as president was 2016.
- Starting in 2006, I moved to the University of Pittsburgh, and soon became founding director of its World History Center. Until 2015, I led quantitative work on Africa’s large population and how slavery limited it; built global historical datasets with support from NSF; co-edited three collaborative volumes on the world history of science with support from the Andrew Mellon Foundation; and continued work on a textbook on long-term human history.
- By 2000, I made a plan to learn and create a broad statement on world history by the end of my career. Migration in World History (2004) was my first big step in developing such a statement. I also signed a textbook contract at this time. With my expanded outlook, I taught graduate courses on interdisciplinary methodology from 2002 to 2015. I also took a step toward linking African studies more tightly to world history, focusing on the African Diaspora as interpreted in a comprehensive book published in 2010.
- From 1988 through 2003, I focused on methods and questions for world history. In 1990, I was expanding my reading from African history to world history, seeking to understand approaches and interpretations at the global level. I formed a World History Center for research and led the opening of a Ph.D. program with degrees in world history at Northeastern University. I focused on migration history as an approach to world history and concluded this period with a 2003 methodological book, Navigating World History. I closed the World History Center in 2004 due to lack of support.
- In the 1980s, I closely examined African population and slavery. My research under a Guggenheim Fellowship is demonstrated in two books exploring how the slave trade reduced the African population. Also during this period, I completed studies on community in society, culture, and population, including contending perspectives in African art and a book surveying social, cultural, and political history in French-speaking Africa.
- From 1965 to 1985, my research centered on the economic and social history of modern Africa, showing how African growth and decline depended on both African and global influences.
- Beginning in 1963, my graduate studies in African history focused on the centrality of Africa and Africans in world affairs. Although my research has evolved significantly since this time, I continue to study this topic today.