The concept of locus of control is one of the most influential concepts in all of psychological science and practice. Initially proposed by Julian Rotter in 1966, the year 2016 marks the 50th anniversary of his remarkable publication, Generalized Expectancies for Internal versus External Control of Reinforcement. As Perceived Control attests, Rotters concept continues to thrive, which bodes well for continuing its influence for another 50 years or more. Perceived Control commemorates this half-century anniversary by presenting contributions from leading figures, some of whom were there at the beginning, giving readers a valuable historical record that lets us see the key ingredients in Rotters initial contribution. Additional authors present contemporary cutting-edge summaries of the current state of our knowledge while giving us a roadmap for future developments.