The problem of world transformation provides a vital context for viewing adolescent development. It is a very large canvas on which to paint. Yet we must try to understand it because adolescence is, in some ways, very different than it was in our long evolutionary past.

The turn of the twentieth century is a useful benchmark. In 1900, there were hardly any automobiles or household telephones; motion pictures were barely getting under way. There were no household radios, no airplanes, no televisions, no computers. What a difference a century makes! Indeed, now even the changes within a decade are dramatic by evolutionary and historical standards. Never before have such rapid and complex transformations occurred as in our lifetime.

The recent changes driven by technological opportunities have had a huge impact on the economy, on communities, and on families. We have rocketed into a new way of life within a couple of generations. And these changes have had powerful effects on the experience of growing up. Today' children are in a very different situation than their parents or grandparents – in some ways better, in some ways worse. We need to clarify what is better and what is worse – and how to shift the balance from worse toward better.

The human child is an ancient creature, shaped by many millennia of biological evolution in ways that pose critical requirements for adequate development. These essential requirements have to be met if the child is to grow and develop, to thrive and learn, and to pursue a vigorous, constructive, adaptable life.