To me, your insightful child is expressing what it feels like to be in the top percent for IQ. That realization comes in different ways at different times. It is very hard to understand why humans do the things that they do; it can seem to be that they are acting without as much thought as we know is possible by humans.
I thought the early teenage pregnancy story was a poignant example. For us, we see it as a societal issue that is trying to be solved. Around the globe, cultures struggle with such societal issues. When these societal issues continue on and even seem cyclical or impossible to resolve, you think, gosh, humans might be evolving more slowly than we would like.
I would just tell your child that, yes, different people think differently. That continues on throughout life. Also, I think it is okay to be emotional and have expression of those feelings. It would be stressful to keep it inside.
