the Evil Line

In 1937, researchers did a comprehensive survey of a group of Harvard sophomores, with the goal of continuing to follow them throughout life. The study is still going, and its long-term nature provides results that are hard to find in more standard social science research. For example:

The Harvard data illustrate this phenomenon well. In 1946, for example, 34 percent of the Grant Study men who had served in World War II reported having come under enemy fire, and 25 percent said they had killed an enemy. In 1988, the first number climbed to 40 percent—and the second fell to about 14 percent. “As is well known,” Vaillant concluded, “with the passage of years, old wars become more adventurous and less dangerous.”