Contagious: Why Things Catch On

Berger examines how public visibility influences the spread of products, ideas, and behaviors. The chapter begins with an account of Steve Jobs’s decision regarding the orientation of the Apple logo on laptop covers. Initially, Apple oriented its logo to face users when their laptops were closed, helping them position their devices correctly. However, Jobs ultimately reversed this orientation so the logo would appear right-side-up to others when users opened their laptops, recognizing that public visibility could drive product adoption.

Berger introduces the concept of social proof: the tendency of individuals to look to others’ actions for guidance on their behavior. He illustrates this principle through multiple examples, including restaurant selection in unfamiliar cities. People frequently choose restaurants with more patrons, assuming popularity indicates quality. This same principle affects numerous decisions, from voting patterns to smoking habits.

The chapter explores how social proof can sometimes lead to suboptimal outcomes. At the University of Arizona, a study revealed that many students privately opposed excessive drinking but participated in it because they believed their peers endorsed it. This misconception persisted because while drinking behavior remained visible, private thoughts stayed hidden. Similarly, Berger explains a problematic pattern in organ donation: When a kidney becomes available, it is offered to potential recipients in order of their position on the waiting list.