Professor Mark L. Knapp of the University of Texas identified 10 interaction stages of interpersonal relationships. The first five stages cover relational development, the process by which relationships grow. The last five occur during relational deterioration, the process by which relationships disintegrate:
1. Differentiating occurs when the two partners start emphasizing their individual differences instead of their similarities. Some separate activities are healthy in a relationship but, in differentiation, the pulling apart is to get away from each other.
2. Circumscribing is characterized by decreased interaction, shorter times together, and less depth to sharing. The two people might go to public events together but do little together in private. Each person figuratively draws a circle around himself or herself, a circle that does not include the other person. The exchange of feelings, the demonstrations of commitment, and the obvious pairing are disappearing.
3. Stagnating suggests a lack of activity, especially activity together. Interactions are minimal, functional, and only for convenience. The two people now find conversation and sharing awkward instead of stimulating. During this stage, each individual may be finding an outlet elsewhere for developmental stages.
4. Avoiding brings reluctance to interact, active avoidance, and even hostility. The two former partners are now getting each other's way, each seeing the other as an obstacle or a limitation. The amount of their talk may actually increase, but the content and intent are negative. Arguing, fighting, disagreeing, and flight mark their interactions.
5. Terminating occurs when the two people are no longer seen by others or themselves as a pair. They increasingly dissociate, share nothing, claim common goods as individual property, and give back or get rid of the symbols of togetherness. Divorce, annulment, and dissolution are manifestations of this stage, as are people who no longer live together, former friends who have nothing to do with each other, and roommates who take separate and distant quarters.