Brave new world what ceremony is john excluded from participating in?

In "A Brave New World" by Aldous Huxley , John is excluded from participating in the kiva, the initiation ceremony where boys turn into men.  He is not allowed to participate.   He is considered to be an outsider and is driven out to the desert by the other boys. 

It can provide a social code to protect each citizen's future economical earnings. and then obviously defending the country from invading countries.