I want to recommend this book by Bruce Perry: "The Boy Who Was Raised as a Dog"
It is excellent~! The second link is to his organization: Child Trauma Org
"The Boy Who Was Raised as a Dog" is Bruce Perry's finest achievement… it gives us all the opportunity to unlock the deepest mystery of our species: why some children turn out to be heroes, and others to be predatory sociopaths. Anyone who wants to understand childhood trauma and its heartbreaking consequences must read this book." -- Andrew Vachss, award-winning author and attorney, founder and national advisory board member of PROTECT: The National Association to Protect Children