Objective/Context: This article analyzes how work was valued as a socializing, adaptive, and objectified resource by a set of psychological discourses and practices in Medellín between 1928 and 1975, seeking to offer an account of the gradual process of psychologization of the work environment in that city during the proposed period. Methodology: To the effect, a detailed bibliographical review was carried out, gathering written sources, particularly theses, newspapers, and magazines. The analysis and systematization of this information reveals how worker emotionality was the object of a set of psychological therapies and observations on psychosomatic conditions, as part of an exercise of growing responsibility over oneself. Originality: There is little concern in national historiography about examining in depth the forms of labor performance management through psychological discourses and practices. Hence, the novelty and relevance of this article lies in the study of historical relations between power and knowledge, between “psi” discourses and practices and labor productivity. In other words, the article is relevant in that it explores how the reality of the world of work has been incorporated into contemporary performance imperatives. Conclusions: The article evidences a progressive emotional intervention that optimized behaviors and gave rise to a new work ethic. Enthusiasm for productive work was built under criteria of knowledge of personality, social valorization, growing emotional management, and demand for regulated rest. The gradual psychologization of the work environment also sought to establish a device for detecting and calibrating emotional ailments triggered by excesses in work and the surrounding social environment.