Homans was very interested in Henderson's conceptual scheme as a way of classifying phenomena and applied it to his own study of small groups. Henderson's teachings were included in Homans' work "The Human Group" (1950). This book's ultimate goal was to move from a study of the social system as it is exemplified in single groups toward a study of the system as it is exemplified in many groups, including groups changing in time. The work has a theme of, "the way group norms develop and the ways a group, consciously or unconsciously, seeks to maintain the cohesion of the group when members depart from group norms." Homans establishes that, "the general propositions would have to meet only one condition: in accordance with my original insight, they should apply to individual human beings as members of a species."