Generalizations or assumptions are often made about the characteristics of members in a group based on an image. When one imagines what a person is like without looking at them as an individual, errors are often made. Example: A couple gets lost in a big city and finds themselves in a low-income community. They lock their doors and try not to make eye contact with the children and adults walking on the sidewalk. The couple fears everyone living in this environment will try to steal from them because they are too lazy to find a job. This is an example of what theory?