Contrary to the declarations of some anthropologists, matriarchies do exist. peggy Reeves Sanday first went to West Sumatra in 1981, intrigued by reports that the matrilineal Minangkabau--one of the largest ethnic groups in Indonesia--label their society a matriarchy. Numbering some four million in West Sumatra, the Minangkabau are known in Indonesia for their literary flair, business acumen, and egalitarian, democratic relationships between men and women.