Yes, I think video games impact a player's social development, because the person is playing video games rather than doing the other things that they should be doing to socialize. In the real world, a person has to have real interactions. If they are busy playing video games, there is no opportunity for real meaningful interaction.
When kids play video games for long periods of time it tends to influence their way of thinking of what is good and bad. For example, say you are playing a war game as a 7 yr old and you play this game often without spending much time with your parents. Being a kid, if you kill someone on the video game and the cpu tells you great job for killing someone due to the fact they were assaulting a "friend" of yours on the video game, you as 7 yr old kid might think after playing that game and real life events that it is justified to kill someone for assaulting a friend of theirs. Now maybe you might disagree with me, but I have evidence to back it up.
I think that video games can in fact impact a player's social development, but not in a negative way. I have always been a shy and anxious person and playing video games has helped me open up and come out of my shell in a lot of ways. Interacting with other people in MMORPG's and being in guilds and alliances has allowed me to communicate in ways that I would have been afraid to before.
I think there are some video games that have a definite impact on a player's social development. Some games are very realistic with ongoing story lines. Continued play over time becomes social interaction with the games characters and lifestyles. After a period of time, a players social development will have been affected by this game as he or she adopt some of the nuances of the game.
I do not believe video games impact the common player's social development. People can also play games in company and groups, so the lone-gamer sitting at home is sometimes a fallacy. For a person who doesn't spend the majority of their time playing, which is normal, games offer more benefits and they don't inerfere with social development at all.
Video games in and of themselves do not impact a player's social development. In fact, gaming can help improve critical thinking skills, which can help in social situations. However, if a person spends too much time playing video games instead of going out and socializing with others, it can begin to impact his or her social development.