Final answer:
Psychosocial development is one of the three domains of lifespan development that focuses on emotions, personality, and social relationships, studied by psychologists.
Step-by-step explanation:
The subject of the question is Psychology. Psychosocial development is one of the three domains of lifespan development that developmental psychologists study. It focuses on emotions, personality, and social relationships. Physical development involves growth and changes in the body and brain, while cognitive development involves learning and thinking skills.
An example of psychosocial development is the formation of healthy attachments in infancy. Developmental psychologists study how parent and infant attachment bonds form and how neglect can affect these bonds.