Insurance costs are all about risk.  When it comes to charging an individual for insurance, they have a million and one factors to look into.  What is their age, gender, driving record, vehicle, etc.  No one will insure someone without knowing how likely they are going to cost them money and how much.

Insurance costs are determined by actuaries.  A actuary uses probability and statistics to rate the risk of an individual.  According to statistics, young drivers have less experience and are therefore more likely to get into accidents or have traffic violations.  In the past, young drivers have cost insurance companies more.

This is why insurance companies charge higher premiums for car insurance for young drivers.  As time goes on, each individual will crate their own reputation.  If you avoid accidents and get no traffic violations year after year, your premiums will go down.  If you get into one accident after the other and pile up your tickets, they will skyrocket.  Be smart, drive safe, and everyone wins.