Final answer:
Abraham Maslow is most well-known for proposing the hierarchy of needs, a framework that suggests human behavior is motivated by fulfilling a series of needs from basic survival to self-actualization.
Step-by-step explanation:
Abraham Maslow and his associates proposed the three-needs theory, which is also related to his well-known concept of a hierarchy of needs. This hierarchy suggests that after fulfilling basic survival needs such as food, water, and shelter, individuals are motivated by higher-level needs, culminating in self-actualization, where one realizes their fullest potential. Alongside Maslow, Carl Rogers contributed to the humanistic perspective in psychology, focusing on an individual's potential and utilizing client-centered therapy. This approach emphasized the importance of unconditional positive regard, genuineness, and empathy in therapeutic settings. David McClelland, another psychologist, also studied motivation and is well-known for his work on needs, specifically the need for achievement, power, and affiliation.