What is maturational theory and who defines and he said? ?

Maturational theory is a psychological theory that suggests that development is primarily determined by biological factors and genetic maturation. This theory was proposed by Arnold Gesell, an American psychologist and pediatrician, who believed that children go through a series of predetermined stages of development that are largely influenced by their genetic makeup.

Gesell argued that children's development is largely driven by their biological maturation, and that environmental factors play a secondary role in shaping their development. He believed that children progress through a series of stages in a fixed, predetermined sequence, and that each stage is characterized by specific behaviors and abilities.

Overall, maturational theory emphasizes the importance of biological factors in shaping human development and suggests that children's growth and development are largely predetermined by their genetic makeup.