The concept of the Window of Tolerance was introduced by Dan Siegel, a clinical professor of psychiatry. This idea describes the optimal zone of arousal where a person can effectively manage their emotions and respond to stress.
Carl Rogers, in his person-centred approach to therapy, emphasized the inherent potential for growth within each individual. He believed that individuals possess a natural drive towards self-actualization (Rogers, 1961), a process of becoming the best version of oneself. This drive is rooted in what he called Organismic Processes – the innate, biological tendencies that guide our development and well-being.
Carl Rogers, a pioneer in humanistic psychology, envisioned an ideal state of being he called the fully functioning person.