[Amaryllis]

Different dogs have different temperaments, and temperament is genetic. However, you really need to socialize this dog as much as possible, to everyone and everything, and you need to keep doing it for life. Yes, you can't undo genetics, so you'll never make a social butterfly out of a timid dog, but you can make him far more comfortable and confident with life. If you do nothing, this poor dog will be afraid of everything, and that's no way to live.

Don't allow strangers to touch him, loom over him, etc. Simply expose him to strangers. Let him set the pace. Find the highest value treat you can (hot dogs, cheese, liver, steak, chicken) and give him those treats whenever you socialize him. You won't teach him to be afraid (some people say that if you give a fearful dog treats, you're reinforcing fear. this isn't true.), you will teach him that seeing strangers = awesomest treats ever. He may even come to look forward to these sessions.

Work up to having people crouch down and offer him a treat, but not petting him. Let him take his treat and back off. Eventually, he may be okay with gentle petting on the chin or neck, but he has to choose to allow that. Don't let people force it on him. Seriously, if you have to body block people to prevent them from scaring your dog, do it. He'll be grateful for your protection.