|2022/05/19 – Bryce Morsky|
The Impact of Threshold Decision Mechanisms of Collective Behaviour on Disease Spread.
- Presenter: Bryce Morsky PhD, Queen’s University, Postdoctoral Fellow.
- Abstract: Humans are a hyper social species, and transmission of infectious diseases crucially depends on social dynamics such as impacting non-pharmaceutical interventions. Further, the infectious pathogen in turn can be affected via the environment fostered by these socio-biological forces. How do social dynamics impact epidemiology? How does public health policy best take into account these impacts? Here we develop a model of disease transmission that incorporates human behaviour and social dynamics. We use a “tipping-point” dynamic, previously used in the sociological literature, where individuals adopt behaviours given a sufficient frequency of the behaviours in the population.
- Further, this model incorporates behavioural heterogeneity where individuals have varying perceived risks of the disease and preferences for social conformity, and thus varying thresholds at which behaviours are adopted. The thresholds at which individuals adopt behaviours is impacted by the perceived risks of infection: prevalence and death rate. We show how such social dynamics can drive an epidemic, such as by generating waves, and where they can frustrate public policy. In particular, (mis)information is highly important as it shifts the population’s sensitivity to adopting disease mitigating behaviours. This can blunt the spread of disease initially, but cause it to spread quickly once relaxed. Additionally, end epidemic results are sensitive to timing of the behavioural response. Near the optimal response, small errors can result in large increases in the total number infected during the epidemic.