Social networks were being mapped decades before anyone logged on
Long before online platforms borrowed the phrase, sociologists were drawing social networks by hand. In the 1930s the psychiatrist Jacob Moreno sketched classroom and workplace relationships as dots and lines, the first sociograms. His diagrams grew into a field that now studies everything from friendship to the spread of misinformation.
A social network is a structure of actors, individuals or organisations, linked by ties. The approach rests on a bold assumption: social life is best understood through the relationships between people instead of the traits of the people themselves. Critics say this can overlook individual agency, but the method has spread into anthropology, economics, geography, biology and beyond, and now forms part of the wider field of network science.
Its intellectual roots reach back to the 1890s. Ferdinand Tönnies contrasted close personal bonds of community with impersonal, formal ties of society, and Émile Durkheim argued that interacting people create a reality that cannot be reduced to individual properties. Georg Simmel explored how group size shapes interaction and wrote about three-person groups and overlapping affiliations. In the 1930s anthropologists of the Manchester School carried out some of the first fieldwork used for network analysis, and mathematical formalisation followed in the 1950s.
Analysis works at several scales. A dyad is a pair; add a third person and you have a triad, where Fritz Heider's balance theory locates much of social dynamics. A rivalrous love triangle is a classic unbalanced triad, likely to shift as one relationship changes. Researchers also study individuals' personal networks, cliques and whole organisations, looking for bridges, isolates and influential hubs.
At Harvard in the 1970s Harrison White and his students knitted separate traditions together, while Stanley Milgram, in the same department, proposed six degrees of separation. From the late 1990s, researchers including Duncan Watts and Albert-László Barabási applied new models to the data trails of online life. Networks tend to organise themselves, with global patterns emerging from local interactions, though mapping every relationship on Earth would be both impossible and uninformative.
Source: Social network
