A SOCIAL ANALYSIS OF ABANDONED CHILDREN & ABILITY OR INABILITY TO PERFORM LANGUAGE. 2019. The attached video was in regard to Child Neglect especially during developmental years when a caregiver or parent is responsible for a child's welfare. The video shows how that development is negatively impacted when a young child has little human interaction &/or interaction mainly with animals during developmental years.
One child was neglected at 3 years of age and lived with canines adopting their behaviors, e.g. barking, walking on all fours (crawling vs standing), etc.
A study of a toddler interacting with an ape revealed the ape took on human behavior, but as did the child adopting ape behaviors. There are other case studies mentioned on the video.
Per one scientists involved in these types of studies, children have difficulty performing language, if they are not taught by 5 yrs old age, as something happens to the brain when a child is deprived of human interaction. They might learn words but words are not sentences. Sentences must be taught for language, but can these types of extreme neglected children learn after 5 years of age to speak? The girl who was rescued from the pack of dogs did learn language. Her rehabilitation and growth led her back to visit her family, willing to forgive them.