Step 1: Understanding the Concept:
The question asks to identify the key figure associated with the founding of Humanistic psychology. Humanistic theory, often called the "third force" in psychology, emphasizes individual free will, personal growth, and self-actualization, as a response to the perceived limitations of psychoanalysis and behaviorism.
Step 2: Detailed Explanation:
(A) Abraham Maslow: Maslow is one of the primary founders of humanistic psychology. He is best known for his hierarchy of needs, a theory of psychological health predicated on fulfilling innate human needs in priority, culminating in self-actualization.
(B) Gordon Allport: Allport was a prominent trait theorist who focused on identifying and measuring personality traits. His work is distinct from the humanistic school.
(C) Carl Jung: Jung was a psychoanalytic theorist who founded analytical psychology. While some of his ideas about self-realization overlap with humanistic concepts, he is firmly rooted in the psychodynamic tradition, not the humanistic one.
Step 3: Final Answer:
Abraham Maslow, along with Carl Rogers, is considered a principal founder of the humanistic school of thought. Therefore, he is the correct answer.