In fiction, there seems to be a tendency toward main characters, especially females, all having similar appearances. Often white, often slim or at least average build, often long-haired, and so on. In the absence of a character description, some readers default to assuming that’s what the character looks like, and there have been cases where a character who does not fit that image has been depicted that way on the book’s cover.
(That includes one of my own books, several years ago, but I was able to explain to the publisher and cover artist, and they changed it. Some authors haven’t been so fortunate.)
It’s unfortunate that that’s the default mental image some readers—and publishers—have of fictional characters, though. It gives fiction the appearance of being a homogeneous place where no one who’s even slightly different exists. Which is completely the opposite of reality, and isn’t at all fair to those who aren’t seeing themselves represented on the pages.
This is, fortunately, beginning to change. The Tumblr blog Size Acceptance in YA talks about how important it is to have main characters who are overweight—or underweight. The #WeNeedDiverseBooks hashtag gives examples of why it’s so important to represent *everyone*. Both sometimes give examples of books that do show different races, ethnicities, body types, and so on.
On the flip side, I wanted my Deep Secrets and Hope series to have diverse characters, but I’m white. When I was researching for the final book of the series, Ball Caps and Khakis, I was accused by someone online of cultural appropriation because the main character, Manny Park, is Korean-American. I was doing the research so I *wouldn’t* be appropriating anything, but it bothered at least one person.
I think it’s important for everyone to be able to find at least one book with a character they feel represents them, whether racially, ethnically, body-type-wise, sexual orientation, gender, or any of the many other ways human beings are different from one another. Because being different is part of what makes life interesting, and in my opinion, that should show in fiction as well.