best advice i can give you is this:
you ask the question "Are the people the same inside?"
take that question, explore what it means and what implications it can have, what if all the people are the same? how did the come to be that way? its a beginning question that just begs to be answered and expolred more fully. now granted this probably isnt a huge project for you. but if you enjoy writing this is one of the best ways to look at why are you are writing a particular piece, what is the urgency behind it and why is it significant, and there you will find the interesting material that will answer the questions you ask.
i hope that made some sense. 😱