Hi Ramona!
Our brains shape and reshape themselves in ways that depend on what we use them for throughout our lives. Learning language is a nice example of how experiences contribute to each person's unique pattern of brain development.
Young children who lack at least one loving and consistent caregiver in the earliest years may suffer severe and long-lasting development problems. This landmark study of scientific brain research shows environmental stress, even among infants and toddlers can interfere with the proper development of neural connections inside the brain essential to a child's proper social and emotional development (Shonkoff and Phillips, 2000).
Reference
National Research Council and Institute of Medicine.
(2000). From Neurons to Neighborhoods: The Science of Early Childhood Development. Committee on Integrating the Science of Early Childhood Development. Shonkoff, J. P., & Phillips, D. A. (eds.). Board on Children, Youth, and Families, Commission on Behavioral and Social Sciences and Education. Washington, D.C.: National Academy Press.