I want to prepare my children for life in the best possible way (as most parents do), and an important aspect of this is, in my opinion, teaching them about the evil things humans are capable of, so that they can look for signs and try to avoid or fight it. Maybe the classic teaching in this regard is "don't take anything from strangers, don't go with them, no matter how nice they seem". But this does not tell the child what the problem really is. I believe the child is better prepared if they know what could happen if they followed the stranger. So the child should know about for example: rape, torture, drug addiction, violence because of differing sexual orientation or religion... to name a few. But they shouldn't be so terrified that they cannot function properly (like feeling the need to run away whenever a stranger talks to them).
I do think they should confront all those horrors (by reading, watching films, talking about it) in order to be prepared, but I don't know when and in what dosage. I don't want to turn them into psychic wrecks that are too afraid to leave the house, after all.
I am looking for guidelines on how to determine which kind of atrocities my child can mentally handle, and in what way (at their age or current developmental stage). Are there any parenting books on this? Or any other resources?
For movies, there are age recommendations. And the people who give out these recommendations must have some basis for their decisions. What is that basis?
To give a concrete example where I want to teach but don't know how: I have a 5 year old son. We recently listened to a happy-go-lucky children's podcast episode that was about love and affection and that two people of the same sex being affectionate towards each other is as OK as the standard male-female affection. And in the podcast it was said that "some people do not know this yet, they think only male-female is OK, so we should tell them: love is for everyone!". As if homophobia was just missing knowledge like illiteracy... My take on this is: Sure, there are people - mainly kids - who think it is not OK because they have been told so, but not reflected it in any way. But there are also many people who have CHOSEN to find it not OK, and among them still enough to readily use violence against not only those who are homosexual but also against those who promote accepting homosexuality as OK. And I want my son to know this, so that he does not run around happily-go-luckily, being blind to the evil in humans, telling men who are busy throwing gay couples from roofs that they just haven't heard the news yet. Because he will be next. (Some might argue that the topic of homosexuality is not appropriate for a 5 year old and I tend to agree, but it is impossible - at least for me - to check every bit of media before I expose him to it (especially when I found a series to be suitable, I do not pre-watch/listen every episode), just like I cannot plan every step of his life. So at some point he will be confronted with something new, challenging, disturbing. That's why I am asking this question.)