Final answer:
Abraham Maslow and Carl Rogers were leaders of the 'third force' in psychology known as humanism. They focused on the growth potential of healthy individuals and emphasized the importance of self-directed change. Maslow's hierarchy of needs theory and Rogers' client-centered therapy are notable contributions to the field of psychology.
Step-by-step explanation:
Humanistic psychologists Abraham Maslow and Carl Rogers led the 'third force' in psychology, known as humanism. They emphasized the growth potential of healthy individuals and the innate capacity for self-directed change. Maslow is famous for his hierarchy of needs theory, which proposes that human beings have certain needs in common and must meet them in a specific order to achieve self-actualization. Rogers, on the other hand, developed client-centered therapy, where the therapist displays unconditional positive regard, genuineness, and empathy in helping the client work through their own issues.