Tipping point
Also known as: Critical mass, Threshold
The moment a small change pushes a system into rapid, self-sustaining spread.
What it means
A tipping point is the threshold at which an accumulating small change crosses a critical level and triggers a large, often abrupt and self-reinforcing shift in a system's behavior. In social dynamics it captures how a behavior, product, idea, or norm spreads slowly until enough people have adopted it that adoption becomes self-propelling — beyond the point, peer influence, network effects, and social proof do the work, and the trend cascades. Threshold models explain the mechanism: individuals adopt once the fraction of others who already have exceeds their personal threshold, so a population with the right distribution of thresholds can flip suddenly from near-zero to widespread adoption. The same nonlinear logic describes epidemics crossing the basic-reproduction threshold and the minority size needed to overturn an established convention. It matters because it implies that change is often not gradual and proportional but lurching and discontinuous, so well-placed early effort near the threshold can yield outsized, lasting impact.
Examples
Studies of social conventions find that once a committed minority reaches roughly a quarter of a group, it can rapidly overturn the established norm and flip the whole group to a new one.
A messaging app crawls along until enough of your friends are on it that not joining costs you conversations — then the whole year group signs up in a fortnight.
Rooftop solar sits at a trickle in a neighbourhood until a few streets have panels; then installers, chatter and visible proof push adoption past the threshold and it cascades.
First described in Schelling (1971); threshold models, Granovetter (1978); popularized by Gladwell (2000).