Kids learn what is accepted and normal and essentially what is "common sense" from what they observe of their surroundings. It doesnt matter if its good or bad, right or good, it gets absorbed. Parents think they their kids never listen because they dont look them in the eyes, but kids hear everything, even what you dont want them to hear.
They also see everything. video games are getting ultra realistic, and when a child is still in the stage where they are discovering the basics of the World, if they play video games too much, the themes represented in the video game will become their view and understanding of the world.
Video games include violence, sexual references, impatience, anger, vulgar language, cheating and lying, war, selfishness, and a whole book full of themes that a child will turn into their reality.
If a child is playing a video game and sees that the character resolves an issue through violence, they will accept that as the normal way to resolve an issue, so next time they have an issue to resolve, they will see to resolving it with violence as the accepted thing to do and will be confused if you tell them they're wrong, because it has become their reality.
If parents knew more about how children absorb their surroundings, they might be more careful as to what they are exposed to.
A child's perspectives becomes what he or she has perceived in the world as growing up.