In the past, many Native American cultures have treated women and men as equals. In ''A Necessary Balance,'' Lillian A. Ackerman examines the balance of power and responsibility between men and women within each of the eleven Plateau Indian tribes who live today on the Colville Indian Reservation in north-central Washington State.

Ackerman analyzes tribal cultures over three historical periods lasting more than a century--the traditional past, the farming phase when Indians were forced onto the reservation, and the twentieth-century industrial present. Ackerman examines gender equality in terms of power, authority, and autonomy in four social spheres: economic, domestic, political, and religious.

Although early explorers and anthropologists noted isolated instances of gender equality among Plateau Indians, ''A Necessary Balance'' is the first book-length examination of a culture that has practiced such equality from its early days of hunting and gathering to the present day. Ackerman’s findings also relate to an examination of European and American cultures, calling into question the current assumption that gender equality ceases to be possible with the advent of industrialization.