A younger driver who is just starting out with their 1st years insurance will have no insurance history and thus will not have been able to build up a no claims bonus.
Younger drivers are of higher risk than older drivers, however many insurance companies specialize in these type of policies as they can charge higher premiums.
Although a young driver may have passed there driving test, this tells the insurer that they have the required skills to drive, however there attitude on the road will still have to be tested.
It has also been proven that the reaction times of young drivers can be considerably slower than that of someone in there 30s.
With there being so many risks involved in young drivers, you are likely to have to pay a high premium initially until you build up a no claims discount.