Happiness and Success: Chicken or Egg

The rapidly growing field of positive psychology seeks to turn long held conventional wisdom on its head.  Since early childhood we are taught that focus, discipline and hard work leads to success - which ultimately brings happiness.  What if the opposite is actually true?  It is a happy individual who is more likely to be successful.  This is the message of Shawn Achor's work - who is a professor at Harvard and published a few books on happiness.  He has glib arguments to persuade you into believing his view - which, I concede is backed by research.  I randomly came across an audio version of his book, Before Happiness, while on a transatlantic flight. It made for compelling listening.  Many of the experiments listed on this site were conducted with graduate and medical students.