The psychologist who discovered this, Seligman, had since turned to studying the opposite: the psychology of happiness. Check out his TED talk, where he talks about his new research: http://www.ted.com/speakers/martin_seligman.html

In summary, according to Seligman, the three levels of a happy life (in order of short to long-lasting): 1. pleasure (physical comfort, great food, etc.) 2. engagement (loving what you're doing, e.g. getting into flow state while coding) 3. meaning (be part of something larger than yourself, e.g. Mother Teresa, Gandhi)

Of note is that, in Seligman's original experiment, a percentage of the dogs never gave up, i.e. never learned that they were helpless. they kept on trying despite their efforts never paying off. when they were put in an environment where they actually had control, they quickly took charge of their own lives (at least in terms of avoid electric shocks) -- a heart-warming story to entrepreneurs.