"It would be folly to argue that behavior can be predicted with perfect accuracy," George Gallup, the godfather of polling, said many decades ago. "It can't and never will be. But behavior can be predicted with a high degree of accuracy. The goal is to increase this accuracy."
On the eve of World War II, 39 percent of the Americans Gallup polled said the health of their families would improve if they only had more money to spend on food, and if they had more money, they would spend it on meat, vegetables, milk and fruit.