Introduction

When I awake in foreign hotels late at night with jet lag, I sometimes turn on the television. This often is the best time to watch for official government messages about how to avoid malnutrition, AIDS, malaria, diarrhea, or a host of other modern plagues. Campaigns like these to increase health and reduce disease are an increasingly important part of public health work, although their appearance at 3 a.m. belies their importance relative to other shows and advertisements on television. Where do these messages come from, and why do they often appear when they are least likely to be seen?

Organized attempts to influence human thought, motivation, and behavior, and the environment in which that behavior takes place, are called “interventions” in today's public health vocabulary, and “intervention research” is its own domain. World AIDS Day (December 1) is designed to increase awareness of health concerns. Television campaigns to promote exercise, condom use, low-cholesterol diets, or mass immunizations are undertaken to increase behavior thought to prevent disease. Campaigns to reduce smoking or alcohol consumption aim to reduce behavior thought to promote disease.