Social networks are these intricate things of beauty, and they’re so elaborate and so complex and so ubiquitous that one has to ask what purpose they serve.

Christakis is marveling at the sheer complexity and pervasiveness of human social networks—patterns of friendship, kinship, influence, and information flow that arise without central design. By calling them “things of beauty,” he frames networks not merely as tools but as emergent structures with their own logic and elegance. The rhetorical question—“what purpose they serve”—pushes beyond description to an evolutionary and functional inquiry: why do such costly, intricate social arrangements persist across cultures and history? The quote encapsulates a core theme in network science and social epidemiology: that networks shape behavior, health, norms, and cooperation, and therefore must have deep adaptive and societal functions.