Aggregate and Category are often mistaken for a group. Aggregate is a collection of people who share a physical location but do not have lasting social relationship.These people are all headed in the same direction, but don't have anything in common other than that.Category is a group of people who share a common attribute but don't think of themselves as having anything in common. This picture shows a picture of a tall man. people might think that anyone who is tall should play basketball but this guy doesn't play any sports.