Why not set up some kind of savings a/c with the money instead? Preferably one that ties up the money for a few years so that when he's, say, 28 he can have the deposit on a house or set up a pension or whatever make most sense. Or maybe he'll just blow it on a new car but as the other posters have said he is an adult and it will be his money at that stage anyway.
But then again if he's planning to travel for a year he must have some savings so maybe he's not as financially clueless as you think, he just has different priorities right now.