If a teen learns to drive with an adult over the age of 25, hey learn how to learn responsibly. Now if you don't let anyone drive until they'er 18 they will have less experience and more accidents. when they learn with an adult they can get corrected so that when they're driving by theirself's they can remeber how to get on the freeway or how to make a "U" turn. So if you put someone that was 18 that has never driven before on the road with someone that was 15 and had plenty of practice....I'd be more fearful of the 18year old.....and also I'm 15