For the purposes of this exercise, let's assume you're a writer.
Your genre is fantasy (or "high fantasy"). You've created a race of people who have wings. You have a gift of description that leaves your readers breathless with the beautiful images of purple feathers and soft collars of down. In fact, this race is so ancient that you have no real reason to create a complete backstory for them because they "have always been."
|Submitted without comment...|
Then one sits in a chair.
Now, for a moment, lets ignore all the other issues this world has, such as your winged people living in houses. Let's just focus on that one detail for a moment.
In your home, you have chairs. No, really. Don't believe me? Go look. I'll wait. See? Told you. Now, in your description of these chairs, you go on and on about highly decorated ornate backs of wood and employ your gift of descriptive imagery to its full extent. The chairs in your world are beautiful and realistic to all the readers.
|Pictured: Your character's chair.|
They're also wrong. Here's why.
Follow my thought process here. Intelligent species first begin designing object to use out of utilitarian need. We design things that fit our bodies, and if it doesn't, then why on any world would we create them? Do you see the problem yet? Okay... Here it is: If your character, which you describe as the size of a roughly good sized human, has wings large enough to bear him aloft in accordance with the laws of physics, he could not physically sit in a chair because he would break his wings.
|"Dammit! This is why we can't have nice things!"|
The same thing applies to every aspect of this new world in which the dominant species has a twelve-foot wing span. So now it becomes your job as a writer to build your world backward, so you can see what would've been built how, and why. A species with a twelve-foot wing span would not, for example ever build anything that would necessitate the crushing of one's own wings. In fact, if you take into account physical limitations, this particular species would, likely, have invented the bar stool long before it ever invented something as obviously meant for torture as a "chair."
|See? No backs, no wing crushings.|
Now apply this to other areas. For example, a "bedroom." What's the first thing you like to do when you wake up in the morning? Stretch, right? Now take a good look at your bedroom. Hard walls, low ceilings, etc. If you had a twelve-foot wingspan, would you ever be caught inside something like that? Chances are, no. Chances are, it would be torturous for you. Small windows, roads, vehicles... None of it would even exist in a world where the dominant species had wings. Hell, roads might not even exist.
The point is this: You need to think it through. Build your world from the bottom up with the dominant species in mind. There's a brilliant joke that the late great Douglas Adams wrote in The Hitchiker's Guide to the Galaxy which involves a multi-limbed creature that was unique in the universe in that it invented underarm deodorant before it discovered the wheel. Necessity. It's why we create things. Your species would do the same.
When you build a world, start with your species. Then ask yourself a series of questions:
- What are its needs?
- What are its limitations?
- How are they like me?
- How are they dissimilar?
Make good choices for your characters and make your world more believable. I don't mean make your readers think the world is real, but at least make them wonder at the possibility. Otherwise, you have creatures who are doing incredibly uncomfortable things for their anatomy. Like sitting in chairs.