[6] The major themes of David McClelland's work were on personality and the application of that knowledge to helping people make their lives better.

McClelland claimed that motivation is "a recurrent concern for a goal state or condition as measured in fantasy, which drives, directs and selects the behavior of the individual".

[10] He shifted his work in the 1960s to focus on the power motive, first addressing issues of addiction and alcoholism (McClelland, Davis, Kalin and Wanner, 1972), then to leadership effectiveness,[11][12] and later to community development.

[13] The work on leadership and management helped to create a behavioral level of a person's capability, which McClelland called "competencies.

'[14][15] He also led efforts to show how important competencies were relative to knowledge and traditional personality traits in the desired outcomes of higher education (Winter, McClelland and Stewart, 1981).

[16] In an exception from the typical focus of a psychologist, McClelland also examined cultural and country-wide effects of motives and related them to large-scale trends in society, such as economic development, job creation, the provocation of wars and health.

Specifically, he claimed that operant methods had greater validity and sensitivity than respondent measures (i.e., tests calling for a true/false, rating or ranking response).

[17] He claimed his lifelong quest was to instill in psychological researchers a value of extracting people's actual thought (i.e., conscious and unconscious) along with their behavior.

He was repeatedly publishing research and encouraging his doctoral students and colleagues to show that operant methods, as compared to respondent methods, consistently show: (a) more criterion validity; (b) increased insightfulness despite less test-retest reliability; (c) greater sensitivity in discriminating mood and such differences; (d) more uniqueness and less likelihood of suffering from multicollinearity; (e) greater cross-cultural validity, because they did not require a person to respond to prepared items; and (f) increased utility in applications to human or organizational development.

The early projects addressed entrepreneurial development and training in achievement thinking and behavior for small business owners in India, Tunisia, Iran, Poland, Malawi and the US.