> I have a number of friends who are teachers, all of whom say that you can spot a single child within about 5 minutes of observing them. They just act differen

> I have a number of friends who are teachers, all of whom say that you can spot a single child within about 5 minutes of observing them. They just act differently. Differently how? Whenever a student comes late to class, I've always imagined that those students who look up from their work are more likely to come from rural areas in Norway, and that those who don't look up to see who is coming are more likely to come from the city. But I don't really know what the difference in behavior would be for a sibling vs only child.