The Tipping Point

The argument is that ideas, products and behaviours move through a population the way an infection does, which means they have a threshold — a point where a small additional push produces a disproportionate result. The book is an attempt to say what determines where that point sits.

Three factors: a few unusual people who know everyone, know everything, or can persuade anyone; the stickiness of the message itself; and the power of context, which is the claim that behaviour is far more sensitive to immediate surroundings than we believe. The case studies are the memorable part — Hush Puppies, the fall in New York crime, why Sesame Street tested its own episodes on children.

It is the book that established the popular-social-science genre, and its weaknesses are that genre's weaknesses: some of the research has not replicated, and the broken-windows chapter has aged into a live political argument. Read as a way of thinking about thresholds rather than as settled findings, it is still the clearest statement of the idea.