This module is designed for students with a high school algebra background. The goal is to present the elements of the group idea, primarily by way of a geometric model, and to see its application to the study of kinship relations within certain human groups. The material opens with a presentation of clans in a hypothetical society in an early stage of development. It is noted that the application of mathematics to social-science questions is not nearly as "clean" as in the physical sciences, but models of the type used have been helpful to those who study the structures of complex human organizations. Exercises are included, with answers provided at the conclusion of the module. (MP)