Dr. Ray’s Answer
The following are books I read in the last year and enjoyed;
John Tierney and Roy Baumeister Will Power: Rediscovering the Greatest Human Strength.
Susan Cain Quiet: The Power of Introverts in a World That Can't Stop Talking.
Both are written for the layman but do a good job of describing the science behind their conclusions.
Ray Finn, Ph.D.