 Much of his work was done with his "wife and constant collaborator" of 42 years Marion Stirling (nee Illig, later Pugh).Stirling began his career with extensive ethnological work in the United States, New Guinea and Ecuador, before directing his attention to the Olmec civilization and its possible primacy among the pre-Columbian societies of Mesoamerica.His discovery of, and excavations at, various sites attributed to Olmec culture in the Mexican Gulf Coast region significantly contributed towards a better understanding of the Olmecs and their culture.