Elliott Jaques was a Canadian psychoanalyst and organizational psychologist. He developed the notion of requisite organization from his 'stratified systems theory', running counter to many others in the field of organizational development. He developed the concept of 'social systems as defense against unconscious anxiety' which shed light on the close relationship between organizational task and unconscious group dynamics and how each can aid or distort the other. Jaques' ideas are still very influential in the psychoanalytic study of organizations. He is most widely known for his concept of the "time-span of discretion," a measure of how much responsibility an employee has. Jaques argued that the higher a person was in a hierarchy, the longer he could work to complete a task without supervision. The time span of a CEO of a major institution might be 15-20 years. This concept enabled him to describe a "requisite organization" as one in which each level in the hierarchy had its own distinctive time span. If an organization had too many levels, then their time spans overlapped. In this case managers at a higher level would interfere in the work of managers at a lower level. The process of delegation would be undermined leading to organizational dysfunction.