I've heard from a couple of teachers, that modern children are harder to deal with than the ones in the time of my childhood.
Teachers complain that children come to school totally unprepared to living and working in society, which means their parents didn't take the responsibility of teaching them the basics of social behaviour.
Some parents may think such a behaviour is already a part of human nature, others believe that school must cultivate appropriate communicative and interactive skills in their children.
School is the place we get most of our primary knowledge and social behaviour is not an exception.
A class is a small model of society, and no doubt, a good place to learn and practice one's social behaviour.
On the other hand, child learns much from his/her family as this is the very first social unit he/she lives in.
The knowledge which comes from parents is the most valuable for a young mind as it blindly believes everything they say and do is right.
So when the family appears to be no good example of behaviour, a kid from such a family is likely to have problems with assimilation in classroom society.
Personally, I believe that this is of direct interest of the parents to prepare their child to a social life as this will help interaction with other children as well as teachers, which is important for the learning process in general.
When i was a child I heard the following expression: «A teacher is the second mother», which i fully agree with and, moreover, I think it may be extended by «mother is the first teacher».
My opinion is that both school and family are responsible for teaching children how to be good members of society, and in co-operation they will succeed.