I am with Mustang1 - John Gray's advice is actually excellent as far as what I have seen in my life. Maybe some people don't like that he generalizes, but that at least gives you a map from which you start. The above posters are right about physical activity. Let him be alone, it's ok. Encourage him to express his anger and emotions rather than hold them in, but do it by agreeing with him on certain things, like saying, "Yeah, me too." Short sentences, nothing long that could be interpreted as being patronizing. Just acknowledge him. That's what guys want the most - appreciation for what they do and acknowledgment of their presence/feelings. Just that little bit should take you pretty far in communicating with any guy at any age.

If you have had a rocky start with him, then anything you say may be seen as disingenuous, and he will react badly and be confused. In such a case, better to not talk with him and rather lead by example to get his respect, and then he will start to open up more about feelings, etc. when the time is right.

Good luck, my SS12 is hitting that stage too, but his BM noticed how much better I am with him than she is, even though he is a bit of a mommy's boy. When it comes to real issues, he really prefers the male voice of reason to chat with. Don't be discouraged, his love for you has not gotten any less if he seems to act more distant.