The scientific study of human development is known as "human development theory" or "developmental psychology." This field investigates the psychological growth and changes that occur throughout an individual's life, from infancy to old age. It explores various aspects, including cognitive, emotional, social, and physical development. Researchers in this field study factors that influence development, such as genetics, environment, culture, and relationships. Understanding human development helps in addressing issues related to education, parenting, and mental health, ultimately contributing to the well-being of individuals and society.