Social Penetration Theory has been appealing since its inception nearly thirty years ago. Altman and Taylor have proposed an intriguing model by which to view relationship development. The theory is versatile, allowing students and scholars of communication to employ it in a number of ways. Researchers have integrated the simplicity of social penetration thinking into their scholarship.

For instance, the effects of self-disclosure on various types of relationships has been studied and written about across a variety of populations. Families (Golish, 2000; Turner & West, 2002), teachers (Russ, Simonds, & Hunt, 2002), marriages (Dickson & Walker, 2001), and physician–patient relationships (Agne, Thompson, & Cusella, 2000) have all been studied. Therefore, the theory is heuristic as it has spawned literally hundreds of studies on self-disclosure and relationship development.

Interpersonal communication scholars, however, are not without their doubts about SPT. Specifically, some writers contend that self-disclosure in particular may be too narrowly interpreted in the theory. For instance, Valerian Derlega, Sandra Metts, Sandra Petronio, and Stephen Margulis (1993) believe that self-disclosure depends on a number of factors, not simply the need to reveal to people over time. Because people are constantly changing, the authors argue that what is considered to be self-disclosure often depends on the attitudes of a relational partner. Further, they indicate that self-disclosure is not always a linear relationship event. Derlega and colleagues conclude that "self-disclosure and close relationships do not necessarily develop over time in a parallel, incremental, and continuous fashion" (1993, p. 26).

Other scholars have weighed in on relational development as well. They reject the notion that relationship development is linear. Mark Knapp and Anita Vangelisti (2000), for example, believe that "relationships are nested within a network of other social relationships which affect communication patterns manifested by the partners" (p. 38). Therefore, other people may influence the direction of a relationship. In addition, the linearity of the theory suggests that the reversal of relational engagement is relational disengagement (recall that Altman and Taylor likened relationship disengagement to a film shown in reverse). Leslie Baxter (1983), however, questions whether relationship deterioration is the reversal of relationship development. In fact, Baxter (1984) discovered that several elements exist in relationship breakups. Her work suggests that relationship development is not the clean process originally reasoned by Altman and Taylor.

Finally, the model's emphasis on self-disclosure may be misguided and inappropriate. Daniel Canary, Michael Cody, and Valerie Manusov (2000), for example, conclude that once relationships are established, self-disclosure does not necessarily continue to play a pivotal role to the degree that it once did early on in the relationship. Further, Canary and his colleagues believe that intimate expressions are frequently accompanied by bouts of conflict, emotional voids, and awkwardness in communication (recall the dark side of communication presented in Chapter 1). Therefore, the theory, as Altman and Taylor conceptualize it, is somewhat limited by its linearity and its emphasis on self-disclosure.

To be fair, Altman has subsequently refined his original thinking on the social penetration processes. He now believes that being open and disclosive should be viewed in conjunction with being private and withdrawn (Altman, Vinsel, & Brown, 1981). This dialectical perspective is similar to that proposed by Baxter and Barbara Montgomery in their theory on relational dialectics (Chapter 12). To be sure, Jason LaSalle and Elise Porter will surely experience the push and pull of self-disclosure as their relationship progresses. It is likely that as both of them share pieces of information, each will also remain private about other issues. And despite the critics' charges, Taylor and Altman (1987) claim that "many researchers have been influenced by the ideas from social penetration theory, but few have directly tested propositions from the theory" (p. 272). The experiences of people like Jason LaSalle will continue to be studied by researchers. His relationship with Elise requires the sort of thinking that underscores Social Penetration Theory. Although some criticize the theory, it provides an important contribution to understanding the development of human relationships.