Is it normal for an 8 year old to still wail like a baby?

My 8 year old stepson wails loudly like a baby whenever he cries, which is quite a lot. I have 2 older children and have been teaching children for 15 years and have not seen anything like it. He doesn't have any diagnosed problems but he is his mother's only child and they have a weird enmeshed/codependent relationship (to the point that she will not allow him to stay with my husband and I without her staying as well because she says he can't cope without her being there although I have seen in the past that he can). She has eroded his independence and maturity at every turn. So is this normal or a sign of something that he needs help with? He cries whenever anyone other than him is getting attention, he cries to get his way and most times it isn't just tears, there is loud wailing and screaming like a small baby. Even my 3 year old has grown out of this. Tl;dr 8 year old stepson wails loudly like a baby whenever he cries. Is this normal? via /r/Parenting http://ift.tt/2wxhbxQ