Reason for age minimum

[ParkerB]

Hello

I searched the forum for threads that answered my questions, but I could not find anything. 1) I am wondering why there is an age minimum of twenty to enlist under an 18X contract. I understand that the Army wants an ODA to be comprised of very mature people, however other SOF units such as the Navy SEALs or Rangers have no such age minimum. 2) Are there exceptions to the age minimum? In Dick Couch's book Chosen Soldier, he points out that there are a few people at the SFQC who are younger than twenty. I understand that the book documented a 2004 training class, so the age requirements could have changed since then. 3) Is a person's age not relevant if they are already in the Army? According to the Special Operations Recruiting Battalion's Special Forces page, the Army is accepting PFC's for SFAS. For instance, if I were to enlist as an infantryman with an airborne contract, would I be able to attend SFAS after completion of OSUT and airborne school as an eighteen year old?

Thanks, and I apologize if any of these questions have already been answered in other threads.