2015 Reprint of 1953 Edition. Full Facsimile of the original edition. Not reproduced with Optical Recognition Software. This book makes three discrete contributions to the theory of motivation. The first contribution is a theory of motivation; the second large section carefully describes the measurement of the achievement motive through content-analysis of imaginations stories; the rest of the book summarizes a number of experiments with the achievement motive as the dependent variable. McClelland is chiefly known for his work on achievement motivation, but his research interests extended to personality and consciousness. David McClelland pioneered workplace motivational thinking, developing achievement-based motivational theory and models, and promoted improvements in employee assessment methods, advocating competency-based assessments and tests, arguing them to be better than traditional IQ and personality-based tests. His ideas have since been widely adopted in many organizations, and relate closely to the theory of Frederick Herzberg.