Interpersonal Communication

Social penetration theory is a conceptual framework that describes the development of interpersonal relationships. This theory refers to the reciprocity of behaviors between two people who are in the process of developing a relationship. These behaviors can include verbal/nonverbal exchange, interpersonal perceptions, and interactions with the environment. The behaviors vary based on the different levels of intimacy in the relationship.

"Onion theory"

This theory is often known as the "onion theory". This analogy suggests that like an onion, personalities have "layers". The outside layer is what the public sees, and the core is one's private self. When a relationship begins to develop, the individuals in the relationship may undergo a process of self-disclosure, progressing more deeply into the "layers".

Social penetration theory recognizes five stages: orientation, exploratory affective exchange, affective exchange, stable exchange, and de-penetration. Not all of these stages happen in every relationship.

1. Orientation stage: strangers exchange only impersonal information and are very cautious in their interactions.
2. Exploratory affective stage: communication styles become somewhat more friendly and relaxed.
3. Affective exchange: there is a high amount of open communication between individuals. These relationships typically consist of close friends or even romantic or platonic partners.
4. Stable exchange: continued open and personal types of interaction.
5. De-penetration: when the relationship's costs exceed its benefits there may be a withdrawal of information, ultimately leading to the end of the relationship.

If the early stages take place too quickly, this may be negative for the progress of the relationship.

Example: Jenny and Justin met for the first time at a wedding. Within minutes Jenny starts to tell Justin about her terrible ex-boyfriend and the misery he put her through. This is information that is typically shared at stage three or four, not stage one. Justin finds this off-putting, reducing the chances of a future relationship.

Social penetration theory predicts that people decide to risk self-disclosure based on the costs and rewards of sharing information, which are affected by factors such as relational outcome, relational stability, and relational satisfaction.

The depth of penetration is the degree of intimacy a relationship has accomplished, measured relative to the stages above. Griffin defines depth as "the degree of disclosure in a specific area of an individual's life" and breadth as "the range of areas in an individual's life over which disclosure takes place".

The theory explains the following key observations:

1. Peripheral items are exchanged more frequently and sooner than private information;
2. Self-disclosure is reciprocal, especially in the early stages of relationship development;
3. Penetration is rapid at the start but slows down quickly as the tightly wrapped inner layers are reached;
4. De-penetration is a gradual process of layer-by-layer withdrawal.

Computer-mediated social penetration

Online communication seems to follow a different set of rules. Because much online communication occurs on an anonymous level, individuals have the freedom to forego the 'rules' of self disclosure. In on-line interactions personal information can be disclosed immediately and without the risk of excessive intimacy. For example, Facebook users post extensive personal information, pictures, information on hobbies, and messages. This may be due to the heightened level of perceived control within the context of the online communication medium.