Diffusion and Contagion
- What we do is influenced by what others do
- Network effects
- Standards, languages, technologies
- Social constructs
- Concepts or things have meaning and importance through social
- Small world networks make simple contagion (like COVID-19) is really hard to stop!
- Most interventions are network interventions
- Stopping travel attempts to block “long” ties
- Social distancing and shelter-in-place attempt to reduce degree
- The most important people to influence are those with high betweenness centrality
- Most communication-related diffusions are complex
- You don’t change beliefs/behavior just from influence from one other person
- Complex contagions require multiple ties between groups
- This is one reason groups can persist in different beliefs
- Why is the Mona Lisa the most famous painting in the world?
- Because there had to be a most famous painting – success begets success (rich-get-richer)
How does this apply to networks?
- Can we predict who will trigger large-scale information cascades?
- Not very well
- If we look in hindsight, a viral tweet seems genius, appropriate, and well-timed
- There were likely hundreds or thousands of similar tweets
- Luck + (ever-changing) structure of networks matter more than attributes of information or information spreaders
- Network position is also closely related to luck!