Until the 1990s, it was widely accepted in psychology that a person’s actions and behaviors were determined by their past. This deterministic view held that human beings were essentially a series of dominoes – propelled forward by the momentum of what had come before.

Then, at the end of the twentieth century, a band of revolutionary researchers burst onto the scene. These self-dubbed “positive psychologists” provided an almost polar opposite explanation for human behavior: that human beings weren’t pushed by their past; they were pulled by their future.