Of course violent video games can have a negative impact on "impressionable minds". That's why we have a rating system. Obviously a 9 year old playing Grand Theft Auto could have some pretty nasty psychological effects. The brain forms multiple synaptic pathways to accommodate new stimuli until about the age of 15, so heavy exposer to realistic violence during that time will effect a person's psyche. Games like Star Wars Battlefront, not so much. However, similar data has been found regarding movies, so I highly doubt video games are any more dangerous. What makes games more "dangerous" is that many parents don't understand that games can be just as, if not more, violent than movies, so they are more likely to buy an M rated game for their 9 year old than an R rated movie. However, that's not the game's fault, that's the parents.