My brother Steve is 19 years old—3 years younger than I. He is of average height, slim, and quite good-looking. Steve doesn’t often talk unless urged; then he speaks in a monotone, or mimics the words or tone of the person he is talking to. Steve has many interests: traffic signs, elevators, apartments, interstate highways, big cities, music, and drawing. His knowledge in these areas, though limited, is acute, and he speaks most freely when the subject is, say, the new school crossing signs on Lakeshore Drive. Steve’s artwork reflects his other interests. He draws amazingly accurate freehand road maps, signs, and floor plans of every one of our apartments.