Complex Contagions
Some ideas spread from a single conversation. Others need a crowd. This paper on ‘complex contagions’ explains why.
Start with a simple contagion. A simple contagion, such as a virus, can spread from a single interaction with a host. This concept can also be brought to bear when thinking about how new ideas or information spread. For example, the knowing score of a sports game might spread like a simple contagion. It requires just one interaction, me telling you the score, to spread.
A complex contagion requires many sources of ‘activation’ to spread. An example of a complex contagion may be the adoption of some new fashion. If person A sees person B wearing a bowler hat, they are unlikely to immediately adopt bowler hats. Yet, if they also see persons C, D, E and F wearing bowler hats, then they are much more likely to do so.
Many collective behaviors also spread through social contact, but when these behaviors are costly, risky, or controversial, the willingness to participate may require independent affirmation or reinforcement from multiple sources. We call these “complex contagions” because successful transmission depends upon interaction with multiple carriers.
This is an interesting thing to consider when trying to effect change in an organisation. Let’s take, for example, adopting type-checking for Ruby. As Ruby is not traditionally type checked, this could be considered a ‘controversial’ change. Thus, effecting this type of change looks more like spreading a complex contagion.
With this in mind, we can start thinking about our multiple points of activation. You could, for example, convince key people to also spread your message, or share articles in Slack promoting the benefits of type checking. The practical lesson: if you treat a complex contagion like a simple one — send a single Slack message and expect the team to change — nothing will happen. You need multiple, independent points of activation.