Look in most of ancient literature and teachings. Oh I know, it's hard to believe anything if it is not happening right now, but this is how people used to live. People lived by a certain set of norms. Anything not within these norms was considered not characteristic of humans. There are still norms that guide the lives of humans today, no matter how much we hide from them.
All organisms have certain norms they have to follow.
For example, you would not see a cow typing a paper or a flower speaking with its own voice. Similarly, you would not see a human flying under its own power, that is simply not the way we are made. The distinguishing feature between humans and all other organisms is the human mind. This enables humans to choose their actions. With the ability to choose comes responsibility.