Well there are advantages as well as disadvantages of everything among the major disadvantage is emotional stress. In many cases small children of age no more than 9 are sent away in a strange new land for them and among new people among whom he may not adapt. At such small age a child deserves love of his mom and attention of his father, he has every right to stay, fight or play with his brothers or sisters if any. Lets assume a child is being forced and then when he returns you expect your child to be nice to his parents, you expect him to be familiar with the family customs or traditions if any. Most of all one must no be surprised when a child calls his mom by her first name which in happens in many cases.
Most bording schools don't recieve government funding, so most of the time they can be pretty costly.
In a boarding school students take many days to get adapted to the environment and friends.The food habits of the student may change
I left for a boarding school at the age of nine. Would strongly advise against it. One is scarred for life with an emotional void that nothing else can fill. At a boarding school, one's acceptance is closely tied to one's performance (in sports or academics). This leads one to believe that one must become really good at something in order to be accepted. While this may be good initially for the child (his extra effort will get him far), ultimately at some point, he will realize that he has missed out on celebrating life.