Kevin L. Ladd & Bernard Spilka 
Psychology of Prayer [PDF ebook] 
A Scientific Approach

Reviewing the growing body of scientific research on prayer, this book describes what is known about the behavioral, cognitive, emotional, developmental, and health aspects of this important religious activity. The highly regarded authors provide a balanced perspective on what prayer means to the individual, how and when it is practiced, and the impact it has in people’s lives. Clinically relevant topics include connections among prayer, coping, and adjustment, as well as controversial questions of whether prayer (for oneself or another) can be beneficial to health. The strengths and limitations of available empirical studies are critically evaluated, and promising future research directions are identified.