Sexual development (developmental psychology) is the systematic investigation within developmental psychology of the psychological processes, cognitive changes, behavioral patterns, and social influences that shape the emergence, understanding, and expression of human sexuality across the lifespan. This field examines how individuals develop their sexual identity, sexual orientation, capacity for intimate relationships, and understanding of sexual behavior, considering the interplay of biological maturation, cognitive development, social learning, and cultural contexts. As a core area within the study of human sexuality, it is significant for understanding identity formation, social adjustment, and overall psychological well-being as these relate to the sexual dimension of human experience, focusing on the psychological trajectory distinct from purely biological maturation or medical conditions like disorders of sex development.