They are a normal couple - making the reader think 'it could happen to me as well'. It's another example of where Catherine behaves sensibly, shows signs of moderation, reads the social situations correctly and as a result gets the guy.

This follows from the parodying of the reader who is not able to read either the books or the social situations correctly. Isabella attempts to throw drama and angst into her relationship with James. It initially progresses 'normally' - Isabella's brother introduces him to James, they get to know each other, they get engaged. Isabella needs to inject drama into their relationship by flirting with other men, arousing jealousy, angsting about the lack of money they will have, and aiming for Captain Tilney. In the end she hasn't read the situation correctly, and looses the guy.