We’re all victims of physiognomy. I tend to write against the outward grain, but not exclusively so. You don’t usually read about vertically-challenged samurai, or goat-herds with spectacles and tinea. More often than not, my characters exist solely as brief outlines, dappled with a hint of blue eyes or the shadow of an elevated cheekbone. From my limited knowledge, most people build up a mental picture of the characters when they read, hence the outcry when a novel is rendered in 35mm and the actors reify interior monologue into flesh and bone. I rarely “see” my characters when reading, or writing. Far more important to hear what they’re saying to me than to know if their eyes are blue or brown. My mother always said that it’s what’s inside that counts. You don’t need contact lenses if you only exist on page.
Everyone contradicts their selves. If you’re writing cardboard cut-outs, you’re working in the wrong medium. If life is like a box of chocolates, then people (and people-as-animals, or people-as-foliage, or people-as-computers) are like those amusements at fairs where you can pop your face into an oval opening and have eggs thrown at you. The physical shape may look the same, but there’s a different personality inhabiting it at every moment. I prefer chocolates, but they’re only sweet some of the time. That’s not to say that you should write your characters bipolar, but consider this: how many faces do you put on in a single day?
Try not to project. When I was younger, I used to imprint the people I’d read onto the people I’d met, and then end up bitterly disappointed when they didn’t turn out to be superheroes or dragons-in-disguise. I think my Megatron and Bumblebee toys were my best friends until at least my 7th birthday. In the first three years of school, I made up an imaginary friend based on Tintin who would accompany me everywhere, simply because real people seemed a bit passé in general. I was always suspicious of journalism because it turns real people into characters, whereas fiction turns characters into real people. To my flesh-and-blood friends: if I call you Ishmael, or Steven Stills, forgive me. There’s a saying about old habits and the end of the world.