Psychology investigates how people learn, while curriculum specialists focus on how psychology informs curriculum. Psychology provides essential theories and principles for understanding the teaching-learning process, a relationship cemented by its insights into student-teacher behavior. John Dewey viewed psychology as the basis for understanding how learners interact with their environment, while Ralph Tyler considered it a screen for determining objectives and learning methods. Ultimately, psychology unifies the learning process, forming the foundation for educational methods, materials, activities, and curriculum decisions.

Behaviorism, the first school of psychology to study learning, emphasizes conditioning behavior through environmental changes to elicit desired responses. Prevalent in the first half of the 20th century and regaining importance with individualized education, behaviorists advocate that learning is influenced by conditions, and learners' attitudes and abilities can improve through proper stimuli. Learning experiences can be designed and controlled to create specific learning outcomes, with selective reinforcement being crucial. Behaviorism significantly impacts education, guiding curriculum creation for educators who espouse this approach.

Contrary to behaviorism, cognitivism believes learning is cognitive, explaining human growth and development as cognitive, social, psychological, and physical changes. Jean Piaget's cognitive stages of development, described from birth to maturity, explain learning as a process of maturation based on previous growth, following a hierarchical order with attainment varying by hereditary and environmental factors, though the sequence remains constant. Piaget's theories form the basis for curriculum principles by Tyler, Taba, and Bruner, influencing methods like continuity, sequence, and integration of learning experiences.

Tyler (1962) proposed three methods for organizing learning based on Piaget's theory: continuity (vertical recurrence of skills and concepts), sequence (each experience building on the previous), and integration (horizontally interrelated and unified curricular experiences). Taba reviewed Piaget's four stages, analyzing their implications for intelligence and mental development, emphasizing that complex concepts should be transformed to suit a learner's developmental stage, and incorporating Piaget's assimilation, accommodation, and equilibration processes. Bruner's structure of knowledge also builds on Piaget's concepts, with his learning process including acquisition (assimilation), transformation (accommodation), and evaluation (equilibration).

It is crucial for teachers and curriculum specialists to determine the appropriate emphasis for each Piagetian stage of development and thinking process. This is particularly critical for school teachers, as children typically transition through the second, third, and fourth stages of development during their schooling years.

Humanistic psychology, considered a third force in learning theory after behaviorism and cognitive development, emphasizes that self-perception is key to understanding behavior, action, and learning. Rooted in field theories, it views the total organism in relation to the environment and the personal meaning constructed in a given situation. Learning is explained by the wholeness of problems, as humans respond to organized patterns of stimuli. Abraham Maslow's hierarchy of human needs, arranged in order of importance (physiological, safety, love and belongingness, esteem, and self-actualization), has significant implications for teaching and learning. Unfulfilled basic needs, like love and belongingness, can impede a child's interest in learning.

Maslow's theory and humanistic psychology influence classroom teaching by emphasizing the child's experience, creativity, values, individual dignity, and the psychological development and potential of learners. This approach can enhance the mental health of learners, foster personal feelings among students and teachers, and improve various aspects of human awareness among students.