Smoking and Nail Biting

I have a 3 1/2 yr old foster child, parents are addicts (meth and heroin) and cigarette smokers... I watch her obsessively chewing on her fingers.  There's addictive heredity and likely psychopathology.  I am attempting now to simply make her aware of it, reminding her to take her hands out of her mouth.  She is aware that having fingernails is a benefit to accomplishing tasks (bright kid).  

I have been pondering if there is any research suggesting a connection between childhood finger sucking and nail biting and cigarette smoking.

Obviously each child is unique, but I am looking for tips on breaking this bad patter.  She is a set up for all kinds of life-havoc (tobacco on top of asthma, already suffered from the effects of parental bad choices).,

THANKS!!

[Kevin Kennedy, Ph.D.]

No, there is no scientific evidence that the two are connected. And, in fact, it really does not make much of a difference. Finger biting is a sign of tension, and the most useful way to address it is not by calling attention to it but by having the child engaged in play. In other words, you encourage a competing response rather than focus attention on the behavior you want to lessen.