Stage theories in general describe how we go through distinct stages as we develop. Thus, rather than gradually changing, we typically make sudden shifts to different plateaus of perception and behavior. This may be associated with 'aha's of sudden understanding.
Levinger's Relationship Stage Theory
Relationships go through a series of stages as they mature. Levinger's model has ABCDE stages.
A = Acquaintance/attraction. We meet other people and feel an initial attraction, often based on physical beauty and similarity.
B = Build-up. We become increasingly interdependent as we reveal more and more about our private selves. We get irritated by one another, but the more pleasant aspects may well keep the relationship going.
C = Continuation/consolidation. Longer-term commitments are made, such as marriage. The partnership enters what may be a life-long stable relationship.
D = Deterioration. Many relationships decay, due to several factors. These include relative effort, rewards, barriers to exit (such as marriage and social obligation) and the availability of alternatives.
E = Ending. The relationship ends when partners agree to separate or one leaves.