why does home exert an important influence in the prevention of deliquency?

Hopefully children learn morals at home, right from wrong, how to treat other people, how to cope with frustration, anger, embarrassment etc. If our parents are bad role models, where are we supposed to learn how to deal with life, we learn by observing and listening to our parents. Behavioural problems during childhood often predict subsequent delinquency and criminality

because your family socialise you into the correct norms and values of society eg. you don't resolve an argument with violence etc then when in a situation outside the home they do not get into such trouble.