Final answer:
Researchers studying human development typically focus on physical, cognitive, and social-emotional domains.
Step-by-step explanation:
When studying human development, researchers typically focus on all of the following domains: physical development, cognitive development, and social-emotional development.
Physical development involves growth and changes in the body and brain, motor skills, and health and wellness. Cognitive development involves learning, attention, memory, language, thinking, reasoning, and creativity. Social-emotional development involves emotions, personality, and social relationships.
These three domains are studied by developmental psychologists throughout a person's lifespan, from conception through adulthood.