Boys and Birchos Cohanim

I asked R' Hamburger about boys duchaning and thought I'd share his answer for those who are interested:

He said that traditionally boys didn't duchan until age 18 or until married as only a married man is said to be in simcha. However, if one is in a shul where all the boys are duchaning it would be acceptable for a boy to duchan so as not to feel left out.