Tal Ben-Shahar (Hebrew: טל בן-שחר, also known as Tal David Ben-Shachar) born 1970, is an American and Israeli teacher and writer in the areas of positive psychology and leadership.
Tal Ben-Shahar taught at Harvard, where his classes on Positive Psychology and The Psychology of Leadership were among the most popular courses in the University’s history. Today Tal teaches at the Interdisciplinary Center, Herzliya.[wiki]
If you are interesting in self development and working on your personality, this is the guy who you should focus attention on at the beginning. Science based approach and excellent speakers abilities makes him my number one as far as its about psychology of self-development.
I highly recommend his lectures “Positive psychology” from Harvard University.
“The average is indicative of a trend, not of a necessity or of a universal truth. Often, it is those outside the norm, the exceptional ones, who point to the truth of what is possible.” (Ben-Shahar, 2007, p. 138)
Ben-Shahar, T. (2007). Happier: Learn the secrets of daily joy and lasting fulfillment. New York: McGraw-Hill.