The way society is organized can have a significant impact on a variety of phenomena, from the spread of dangerous diseases to the dissemination of information. To investigate the dynamics of complex systems like society, researchers often use social and transportation networks to represent individuals and their connections. However, these networks can be difficult to control, dense, and enormous.
Researchers at the Instituto Gulbenkian de Ciencia have found a way to simplify these networks by extracting their backbones. The principle behind this method is straightforward – it finds the shortest path to reach every other point in a network and deletes redundant alternatives. The researchers have applied this method to various networks, from gene interactions to communication pathways in the brain, and have found it to be effective.
In a recent study, the researchers took this method to a whole new level by testing it on real human contacts. They used previously recorded contacts between nearly 3000 individuals in social settings, including schools, hospitals, and art exhibits, and transformed this data into social networks. They found that the backbones of social contact networks were very small, indicating that many connections in human communities are redundant. Surprisingly, this backbone still preserved the community structure, stemming from people’s tendency to cluster in groups.
The researchers concluded that the backbone is a reliable tool to explain how processes such as viral infection spread in a population, as well as to identify the most relevant social contacts to stop contagion. But the implications of the backbone of social systems go much beyond epidemiology. The recent pandemic has demonstrated that our social lives and overall public health depend heavily on interactions that cross scales from the molecular network of minute pathogens to all our transportation, health, economy, ecology, and governance networks.
The researchers believe that their basic research on backbones adds another tool in the study of networks that link the tiniest virus to the most potent economy. It is only through the fundamental understanding of how these systems interact that we can solve XXI century problems.
