According to scientists people who play video games have much better reactions, dexterity, multitasking skills and intelligence. Wrap your head around that you people who vote no because this is real evidence.
Reactions: On average video game players have reactions 20% better than non gamers. Some are as even as good as fighter pilots!
Dexterity: A sample of surgeons were evaluated by how they performed. The ones who were faster and made less mistakes were the ones who played video games.
Multitasking skills: Gamers can pay attention to 6 things on average. Non gamers can only do 4.
Although video games and confidence aren't a pair that really correlate too much, I'd say that video games are a good way to keep the mind active. Hand-eye coordination is typically improved in someone who plays video games, which could be a source of increased confidence. However, too much video game playing can be detrimental to someone's health, and thus reduce their confidence.
I believe that video games do improve confidence in people, due to the fact that most games when you play them make you seem like you are the greatest thing ever. The video games make you feel like a hero and that you cannot lose. It is a false since of confidence because when many of these people go into the real world they are quickly cut down.