Listen to the fabulously successful discuss their lives, and you're almost certain to hear them attribute their eventual successes to the challenges that they first faced and overcame. Hardscrabble childhoods, menial jobs, discrimination, disabilities, doubt - these are the cliches of American autobiography. And few would trade away their triumphs in exchange for an easier path through life.
But take a look at their children. They don't pick out failing schools for them to attend or arrange for them to spend their summers in difficult, dangerous, low-paying work. So if adversity paved the way to their own success, why don't they replicate that adversity to give their offspring a similar advantage?
The answer lies in the nature of adversity. Obstacles generally reduce the odds of success. A child at an elite prep school is vastly more likely to gain admission to a competitive university than her peer at an enormous public school in a poor neighborhood, and vastly less likely to end up unemployed or in jail. The average outcomes are so dramatically different that parents would be crazy to disregard them. But adversity also has tail-end effects. For the small subset that surmounts the obstacles, the experience can be life-altering and irreplaceable. They may well be driven to work and to achieve at levels their peers with more comfortable childhoods cannot match.
Social science tends to focus on average outcomes. It makes some allowance for negative tail-end effects. When a medicine, for example, generally alleviates symptoms but also cripples a small percentage of patients, we tend to take notice. But it rarely attempts to identify positive tail-end effects. We find it uncomfortable to consider the moral implications of a policy that might lower average outcomes while raising the odds of extraordinary achievement.
It's an interesting twist to the American dream of giving our children a life better than our own. We want to spare them the things we suffered, but also seek to instill in them the virtues in which we take the greatest pride. And sometimes, those ambitions may prove mutually exclusive.