First, cell phones give young children more opportunities to communicate with peers and their parents. This make the young children learn more skills of communication and by these skills, when these young children grow up, they can get along with the people around them.
Furthermore, cell phone make communication more convenient. If the young children have some problems they can't solve, they can call their parents or the person they know who can solve the problems.
Admittedly,young children cannot control themselves well, so sometimes they use their cell phone to have fun. But parents can give their children a cell phone which can't play games on it.
In conclusion, young children should have their own cell phone because it can help the young children grow up better.