This is an issue that a lot of modern parents think about, whether to allow it to a certain degree or to disallow it completely. As a parent myself, I sometimes struggle whether or not a movie, an X-box game or a TV show is really suitable for my 8 year old. Sadly, we live in a world where the subject of sex and violence, explicit or implied, are considered normal in the video games that our children play, movies they watch or in the lyrics of the music that they listen to everyday. Wholesome entertainment has become super uncool, boring or unfashionable, and you've got a multi-billion dollar industry telling you it is.
It is possible that what media promotes influences the way our youths behave in the real world. In fact, according to the American Psychological Association, who investigated on the correlation between violent video games and aggression, says "..the research demonstrates a consistent relation between violent video game use and increases in aggressive behavior, aggressive cognitions and aggressive affect, and decreases in prosocial behavior, empathy and sensitivity to aggression".
I agree, well, to a certain degree. Even though there is very little scientific evidence to support the theory that violent movies or video games can lead the person to commit a violent act or crime himself, I believe that violent media contributes to it as one risk factor. Just like a young person watching explicit movies with sexual content does not necessarily move him to commit rape or sexual abuse, but it is one of the risk factors - meaning when integrated together with other influences from his environment and association with friends, it increases the risk of him committing more aggressive acts. It does not always lead directly to violent acts but it contributes to the person being subconsciously aggressive, manifesting itself when the situation allows it.
With this in mind, should parents allow their kids to engage in these types of entertainment? I think parents choose from different options.
One is to totally ban the young person from engaging in these unsafe forms of entertainment. They say that even if you stop your son or daughter from doing something, he or she will find a way to do it anyway. The concept here is you will not be influenced by something you are not exposed to.
Another option is to let the young person engage in them when available, but advise them to avoid if possible, or explain the context in which the sexual and violent content are placed in. Basically, with this method, you hope that they will understand that everything is just make-believe, and they shouldn't copy or be influenced by it. The third option is to let the young person decide on his own, since he has his own mind and conscience.
I think that the first one is too idealistic. The influence of multi-media is everywhere, from our movies to books to the Internet, and you can't be there all the time to stop your children from being exposed to it. If you ban them from it, they will find a way to quench their curiosity with people outside of your sphere of influence. The second and third one basically tells them that it's okay to engage in violent forms of entertainment. This is very dangerous because gives too much freedom to a young person still being molded.
There are movies that make violence and illicit sex in a more subtle way and seemingly just part of the plot - or it may be hidden in some sort of extreme sport activity such as mixed martial arts, boxing or wrestling. This is where the "gray-area" sort of comes in, since scripturally speaking, these were not explicitly mentioned or condemned. Even superhero movies or cartoonish video games, which seems to be harmless fun on the surface level, have some level of violence in them. In fact, you'd be surprised at the level of enjoyment these kids are feeling when "killing zombies" or "stealing cars and beating up people along the way". In fact, children adapts the hero of the story as a role model.
You might say, "I've been watching these types of shows all my life, and I've never killed anyone, raped anyone or committed any violent acts. So I think it's safe for my kids to watch them." As mentioned earlier, there is no direct correlation between violent media and criminal activity, but the influence it has on the mind, can alter a way a person treats things in real life - such as how he manages his stress, while driving on the road or his treatment of women. And these violent images stay in our subconscious, until a sudden event in our lives digs out these violent tendencies. Remember that our hearts and minds are easily influenced by today's hypnotic-media-dominated world. Jeremiah 17:9 tells us that "The heart is more treacherous than anything else and is desperate. Who can know it?" For younger kids, we can be more direct, and just let them avoid as much as possible. You can also use the scriptures in a simple way to make them understand why God hates violence.
For the teens or older kids, since you have a little less hold on them and they can just about do things on their own outside of the home, I feel that it is better to help them develop their conscience, discernment or their sense of perception. The first thing to do is to become a role model to them. If they see you avoid these things and engage in wholesome entertainment, they will more than likely follow your footsteps. But to do that, you must maintain your own conscience first. 1 Peter 3:16 says "Maintain a good conscience, so that in whatever way you are spoken against, those who speak against you may be put to shame because of your good conduct as followers of Christ."
Moreover, help them develop and train their own good conscience in choosing bad and good entertainment. If they know that watching something makes them feel aggression or makes them feel sexually tempted, then they should be able to control themselves and turn away from it. What is the best way to help them train their conscience and discernment? Is by guiding them by means of the Scriptures, and encouraging them to use God's word as a guide. In fact it says in the scriptures that we must keep training our children. Deuteronomy 6:6, 7 "These words that I am commanding you today must be on your heart, and you must inculcate them in your sons and speak of them when you sit in your house and when you walk on the road and when you lie down and when you get up."
And more importantly, teach them to always pray for God's guidance such as Psalms 139:23-24 "Search through me, O God, and know my heart. Examine me, and know my anxious thoughts. See whether there is in me any harmful way, And lead me in the way of eternity."
Unwholesome entertainment is all around us, and whether we like it or not, our children will be exposed by it. Media is a very powerful thing. But what we have is protection through meditation of the scriptures and through prayer. We are lucky to have the best guide we can ever have, the Scriptures and God who loves us, and will bless us if we always do the right thing. Let's not be "molded" by this world, and use our well trained conscience to avoid all that is bad so that we may keep doing what is good in God's eyes.
Romans 12:2 says "And stop being molded by this system of things, but be transformed by making your mind over, so that you may prove to yourselves the good and acceptable and perfect will of God."