British anthropologist; student of Malinowski and Firth; fieldwork in Burma and Sri Lanka. Leach's Burma fieldwork was carried out under difficult circumstances before and during the Second World War, and though his fieldnotes were lost, he managed to put together a monograph - Political Systems of Highland Burma (1954) - which has become a classic. In this monograph, Leach (who had remained loyal to Malinowski's and Firth's functionalist anthropology) at the same time contributed significantly to the then dominant structural functionalist focus on political anthropology, and made a noticeable break with this tradition, which pointed forward to the methodological individualism that would soon attain prominence in Britain. The book shows how political leaders manipulate kinship and property rules in their political conflicts, and posits that the outcome of these manipulations is only visible if the entire highland region is viewed as a whole. Individual Kachin villages seemed to be spread out along a continuum from nearly egalitarian to rather hierachical political organizations. Leach argued that these different forms in fact represented phases in a very long-term fluctuation from egalitarianism to hiearchy and back, while confirming Malinowski's old idea that kinship and myth were not morally or jurically binding norms (as structural functionalism claimed), but charters for action, which might be manipulated and reinterpreted by actors in accordance with their interests.

Leach's monograph from Sri Lanka (Pul Eliya, a Village in Ceylon: A Study of Land Tenure and Kinship, 1961) is a classical ethnographic study of economic organization in peasant society.

Leach was (along with Rodney Needham) among the first British anthropologists to be drawn toward structuralism, and during the 1960's, this became his main passion. He published a short, popular introduction to Lévi-Strauss in 1970, and, in 1983, Structuralist Interpretations of Biblical Myth (with D. A. Aycock).

When Leach moved from London School of Economics to Cambridge University in 1953, this became the center of the new, methodological individualist movement in British anthropology. Among his most prominent students were Bailey, Barnes and Barth.