What is a critical mass?
Photo: US Department of Energy. Source: Wikipedia
A critical mass is the amount of fissile material needed to sustain a nuclear chain reaction. The amount depends on the nuclear properties, its density and shape, the surroundings, even the temperature. Enough atoms are splitting and spitting off energy and neutrons to make more atoms split and generate more neutrons and more energy. The chain reaction continues until all the fuel is consumed.
In society, a critical mass is the number of adopters needed to make an innovation grow to become almost universal. We see this in technology today. Ten years ago the iPhone had just come out. Now smartphones are ubiquitous. Twenty years ago people used dial-up modems to connect to the internet. Now, Wi-Fi networks are everywhere. When enough people adopt an innovation – it could be a behavior, a style of clothes, or some other change – the trend “goes viral.” It propagates itself across the population.
The idea of critical mass is a useful mental model to help us understand how change occurs, and to make sense of some of our tumultuous times. For an innovation to become self-sustaining, it needs to be convenient, available, and “sticky” – it has to be hard to stop, once you’ve started. Cigarettes are sticky because the nicotine in them is addictive. Only a significant level of health warnings, social disapproval, and taxes have reversed their growth. Cat videos aren’t very sticky. Even cute ones fade away.
Photo: Doug Tengdin
It takes about 10% of the population to adopt a change for it to become a trend. Sometimes – as in political upheavals – the change can seem to come overnight, whereas, in fact, the seeds of revolution had been growing for years. This was the case in Tunisian and Egypt during the “Arab Spring.”
Critical masses are powerful. They can create positive change, but they can also generate a mob psychology where bad things happen and no one takes responsibility. Understanding criticality is key to evaluating how things have evolved, and where they might be going.
Douglas R. Tengdin, CFA