Anthropologists have come to recognize that in addition to the prevalence of egalitarian relations, many New Guinea societies also exhibit elements of hierarchy as well. This article discusses the nature of hierarchy in some Sepik societies through the comparative analysis of the social structure of four Sepik area societies on the northeast coast of Papua New Guinea. Using Sahlins' definition of ‘heroic societies’ based upon a principle of ‘hierarchical solidarity’, the article argues that the form of hierarchy found in Manam Island society is different in type from that of the neighboring societies of Boroi, Murik and Wogeo. An additional diagnostic feature of heroic societies is what Sahlins refers to as ‘heroic history. In Manam the cultural form this takes is a ‘heroic’ variation of the myth of two brothers common throughout the area.