On one hand, I understand your need to sleep better at night. On the other hand, here are facts:

http://en.wikipedia.org/wiki/Reddit#Demographics

and

http://www.ignitesocialmedia.com/social-media-stats/2011-soc...

As you can see, Reddit is overwhelmingly 25-44. The most represented group is actually 35-44. The high school demographic is negligible, and equal to the 65+ demographic.

Also, if you were to be completely honest with yourself, I bet you would not have made the comment you've made if the jokes and the upvotes were about race and lynchings instead of underage girls and rape.