My DS 15 has similar issues. He is also currently not labeled with anything, but we are looking into expressive language disorders. (There are other problems.) He doesn't really quite fit an ASD diagnosis. Talking with adults he doesn't know well is a struggle. I know that he often listens better if he he doesn't have to be looking straight at you. One great place for conversation is in the car. But I have insisted that not looking at people when they are talking with you is considered IMPOLITE. He insists that looking at another person has nothing to do with if you are listening or not and even insisted on doing his 6th grade science project on the topic. He tried testing to see if the direction you were looking, affected how well you heard a word.
Several things have helped, and maturity seems to be one of them. When my son was in 6th & 7th grade he did a social skills group with a bunch of other boys his age, most of whom where either ASD or ADHD. He did get better for a while, but has been having problems again recently. At this point we are taking him to a pyc. whom deals with gifted kids and are planning on getting him formally tested him this summer.
