How we learn to swap pessimistic worldviews for optimistic ones is among the most fervently pursued subjects of modern psychology. Professor Martin Seligman—director of the Positive Psychology Center at the University of Pennsylvania—is credited with spearheading this effort using insights gleaned from his work on cognitive-behavioral treatments for depression. The core component of Seligman's program is an adjustment of a person's explanatory style—the person's preferred mode of accounting for events. The most critical aspect of optimists' explanatory style is that they reflexively attribute negative events to external, transient causes, while attributing favorable outcomes to permanent, personal factors.