pedology; child development studies
Academic field studying child behavior and development; the term is technical and not widely used in everyday conversation.
Pedology is a field that scientifically studies child development.
児童心理学 is child psychology, which overlaps with 育児学 but emphasizes mental processes rather than overall development.
Compound of 育児 (child-rearing) and 学 (study, -ology). The term is a modern academic coinage.