One writer on the list:
Sonja LyubomirskyRead about another thinker on the list.
Lyubomirsky, a psychology researcher at the University of California and author of The How of Happiness, would almost certainly be genuinely appalled to be described as a "self-help guru" — which is one excellent sign of a good self-help guru. She has led much of the recent research that has started to give some copper-bottomed scientific credibility to certain self-help techniques while casting doubt on others. If you need some peer-reviewed studies to convince you to show appreciation to your partner, keep a gratitude journal, or invest in friendships, you'll find it in Lyubomirsky's work.