<human>: I rescued Morty (8 month old male) last week from a neglectful home. From what I've gathered, he spent the majority of his day in a kennel. He was the only pup of his litter, so the only dogs he was socialized with were his parents and the only people he was socialized with were his owners. When I first met him, he barked for about 5-10 minutes and didn't trust me, but eventually he warmed up to me and now he's incredibly friendly. He's also friendly with my roommate and my roommate's dog, but only after introducing them slowly.
 
I've taken him to Petsmart a couple times and I walk him on campus occasionally. His reactions to unfamiliar people and dogs are mixed. Generally, he'll seem very interested and try to pull towards them (we're also working on loose leash walking). If he does get close, he'll bark at them. What can we do to work on this?  
   
Also, he isn't neutered yet but that's going to happen in the coming weeks. I don't know if that will have any affect on this problem but I thought it might be important to mention.

Can you condense the text into a few key points?
<bot>: Dog wan't socialized at all and is only friendly with people/other dogs if they are introduced very slowly. What can I do to help him gain more trust/confidence in strange people and dogs?