Final answer:
Human development is studied from a scientific perspective using objective methods, such as case studies.
Step-by-step explanation:
Human development is studied from a scientific perspective, meaning that its methods of study are objective. The scientific method provides a system of organization that helps researchers plan and conduct a study while ensuring that data and results are reliable, valid, and objective. Developmental psychologists often use case studies to collect a great deal of information from one individual in order to better understand physical and psychological changes over the lifespan.