You know, I dated a guy who was the exact same way as an adult!! Nip it in the bud before he becomes a 22-year-old male who never accepts responsibility for anything. lol.
As far as HOW to nip it in the bud, my kids are 4 and 1, so I don't have any solid advice that works. Speak rationally to him, explain reasoning for things, and have him explain reasoning, and hope for the best? That's what I will probably do when my kids are that age!