A Developmental Psychologist studies how people grow and change throughout their lives. They focus on various aspects of development, including cognitive, emotional, social, and physical changes. This field examines different stages, from infancy to old age, and how experiences and environments influence development. These psychologists often conduct research, observe behaviors, and work with individuals or groups to understand developmental milestones. They may also apply their findings in settings like schools, hospitals, or counseling centers, helping to address issues related to child development, learning disabilities, or aging.