Wheelchair-bound individuals are helpless. Gays are effeminate. Lesbians wear their hair short. Older adults need constant care. Anglos are either racist or are rednecks.
Homeless people are drug addicts.
Since our brains naturally classify what we see, we can't help but notice the differences in physical attributes between one person and another. But it is not natural to stereotype. As with the printing term used to describe multiple stampings from a single mold, to stereotype is a short-hand way to describe a person with collective, rather than unique characteristics. It is easier and quicker for a photojournalist to take a picture of an angry African American during a riot than to take the time to explore in words and pictures the underlying social problems that are responsible for the civil disturbance. Because visual messages are products of our sense of sight, pictures are highly emotional objects that have long-lasting staying power within the grayest regions of our brain.