I would say that every character in the story is a representative of one type of humanity. Therefore, Young Goodman Brown would only be representative of a type, not of all humanity. His little wife is also representative of a type of humanity--a female type. There is no way that Young Goodman Brown could representative all of humanity--young, old, male, female. This story has a large cast of characters, and it would appear that Hawthorne is using all of them to represent humanity in a way similar to that in which Shirley Jackson uses all her characters in "The Lottery." Young Goodman Brown represents the type who is not yet fully corrupted but is headed in that direction.