A total of 42 studies of children age 0 to 6 years with confirmed neglect or emotional abuse who had emotional, behavioral, and developmental features recorded or for whom the carer-child interaction was documented were analyzed.

Key features in the child included aggression, withdrawal or passivity, developmental delay, poor peer interaction, and transition from ambivalent to avoidant insecure attachment pattern and from passive to increasingly aggressive behavior and negative self-representation. Emotional knowledge, cognitive function, and language deteriorate without intervention. Poor sensitivity, hospitality, criticism, or disinterest characterize maternal-child interactions.

"Lifelong consequences include physical and mental health problems; impairments in language, social, and communication skills; and severe effects on brain development and hormonal functioning." The study concludes, "early intervention has the potential to change children's lives."