The social exchange theory relates to relationships. The theory proposes that relationships are based on weighing up the costs and benefits, and if the costs outweigh the benefits, the relationship will result in breakdown. Costs in romantic relationships could include a lack of satisfaction, a lack of communication or there may be too much physical distance between the couple. If the costs outweigh the benefits, the relationship will breakdown according to this theory. The theory can be applied to romantic relationships, friendships, and other relationships such as colleague relationships.