Bobby says he’s terrified his 8-year-old son could harm or kill his fiancée, Chrysta. Bobby claims that while he and his son lived with Chrysta and her children, the young boy threatened to harm Chrysta, tried to hurt her daughter, hurt animals and destroyed his bedroom. Bobby, who gained custody of his son when he was 4, believes the child may suffer from Reactive Attachment Disorder.

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In the video above, Dr. Charles Sophy, a board-certified adult and child psychiatrist, medical director for the Department of Child and Family Services in Los Angeles and member of the Dr. Phil Advisory Board, weighs in with his thoughts on what may be causing Bobby’s son’s reported behavior.

“There's lots of insults that this child has had, from genetic insult to environmental insults. We don't know what kind of bonding happened, didn't happen during that initial time. Zero to 9 months is a critical time,” Dr. Sophy says. “Our brains are growing through all of this. And so, his brain is reacting to the deprivation, to the screaming, to the lack of food, to the scabies, to being left there. All that kind of stuff impacts the way that your brain grows. So, if your brain isn't going to grow and map the way it needs to, then your neurons don't hook up the way they need to, then your brain doesn't work the way it should, and then you don't react to situations outside the way that you would, and that's why we see him so extreme.”

WATCH: Woman Claims Fiance’s 8-Year-Old Son Tried To Kill Her Twice

Dr. Phil adds, “If a child is not touched, not held, not nurtured at certain points along the way, then they fail to develop certain abilities and certain relationships.”

Hear more in the video above. And, see how a normal brain of a child differs from the brain of a child who has been neglected. Is it possible to change a child’s brain if he starts to be nurtured?

This episode airs Thursday. Watch more here.

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Today’s Takeaway: Four Questions To Ask If Your Child Acts Out