Narrator: This is Science Today. A recent survey of middle-class cultures on their beliefs of love and marriage uncovered a general disdain of Hollywood notions of 'one true love'. Yet, sociologist Ann Swidler of the University of California, Berkeley, who led the study, says it's the structure of marriage as an institution that shapes all romantic relationships in our society.
Swidler: Even those that are not directly leading to marriage - and you see it in the way people use the very word love. They say things like - 'is this right, how did I know this was it?' And when people are trying to decide whether to break off a relationship or whether to divorce, they come exactly to this question. Do I really love him? Do I really love her?
Narrator: Swidler says that's because our society legally and socially defines marriage as an exclusive relationship.
Swidler: The way you need to think to make the all or nothing decision that marriage and marriage-like relationships demand, you need to think about one true love and an all or nothing feeling.
Narrator: For Science Today, I'm Larissa Branin.