Foley has carried out research in many aspects of evolutionary theory, human evolution, prehistory and more recently human evolutionary genetics. His early work was on the
Later Stone Age of East Africa, where he developed methods and ideas to study the landscape distributions of artefacts, giving rise to the sub-field of Off-Site Archaeology. In his work on human evolution he has emphasized an evolutionary ecological approach, seeing human adaptations as solutions to the problems faced by hominins in the environments in which they were living. This evolutionary research has also explored the relationship between climate and evolutionary change, the evolution of social behavior (finite social space model), and patterns of
hominin diversity. This approach was summarized in two books – Another Unique Species, and Humans Before Humanity. Since the 1990s, Foley has collaborated with
Marta Mirazón Lahr on research relating to the evolution of modern humans and their diversity. Their work has argued for multiple dispersals of early humans out of Africa, and the use of the ‘southern route’. Their approach has emphasized the role of geographical factors in shaping human evolution, and a central role for dispersals as the process by which diversity evolves. He has co-led expeditions and archaeological excavations with Mirazon Lahr in the Solomon Islands, the Central Sahara, and Kenya, particularly in the Turkana Basin. In Turkana, Foley and Mirazon Lahr study the late Quaternary record of human occupation in the basin, and have recently described a group of 10,000 year-old skeletons from the site of Nataruk that died as part of conflict between hunter-gatherer bands. In the last decade, Foley has been involved in several aspects of evolutionary psychology and linguistics, exploring questions related to the evolution of human cognition, human language and its use as a mechanism is the evolution of society and social boundaries. He has an
h-index of 51 according to
Google Scholar. ==Honours==