During the 1990s a diverse group of disciplines have simultaneously intensified their attention upon the scientific study of emotion. This proliferation of research on affective phenomena has been paralleled by an acceleration of investigations of early human structural and functional development. Development neuroscience is now delving into the ontogeny of brain systems that evolve to support the psychobiological underpinnings of socioemotional functioning. Studies of the infant brain demonstrate that its maturation is influenced by the environment and is experience-dependent. Developmental...