A model for the decline of trends, fashions and information exchange

A model of human behavior finds that people will share information if they share enough, but not too much, of their contacts. Humans are social creatures and many behaviors and beliefs can spread from person to person. Understanding the dynamics of behavioral diffusion can help encourage healthy or sustainable behaviors or stop the spread of misinformation. Linear threshold models assume that people will adopt a behavior when the number of social contacts that have done so exceeds a threshold.

Pouria Ramazi and colleagues propose an addition to the model, in which people abandon a behavior when the number of contacts who have adopted the behavior exceeds a second threshold. The results are published in PNAS Nexus.

Periods of decline in the adoption of innovations, fads going out of fashion, and gossip becoming obsolete are some of the reasons why a second threshold for behavioral adoption might exist. The authors test their theory using social media conversations on Twitter (now X) around the Higgs boson and the Melbourne Cup horse race, as well as conversations in China on Weibo about the vaccination campaign against COVID-19. In each case, the bi-threshold model outperformed the linear-threshold model.

According to the authors, the results confirm the existence of the second upper threshold in some contexts of information dissemination.