- Hunters and gatherers (past and present)
- Plains-Pueblo interaction
- Middle Paleolithic (Europe and Near East)
- Evolution of human diet
- North America
- American Southwest
- Near East
John Speth studies hunter-gatherers, past and present, New World and Old World. He is interested generally in the evolution of foragers' diet, subsistence strategies, and food processing technologies and, more specifically in the ways that hunter-gatherers (and small-scale farmers) cope with seasonal and inter-annual unpredictability in their resource base. Largely through fauna, he also is exploring the nutritional and economic basis of Plains-Pueblo interaction in the American Southwest and Neanderthal hunting in the Near Eastern Levant.