In addition, perceived relationship compatibility is likely to change over time

Gottlieb’s quote that opened this article referred to the stake that the Internet dating sites have in the idea that “long-term romantic compatibility can be predicted according to scientific principles (p

A relationship may be compatible in early interaction, but the pair may later discover that they are not compatible for a long-term relationship. This is an obvious truism. In fact, one use of the concept compatibility in the relationship literature is in the context of compatibility testing for mate selection. According to “compatibility testing models,” such as Murstein’s (1987) Stimulus-Value-Role theory, partners gain new information about each other as they go through stages of increasing relationship development which involves becoming interdependent in new contextspatibility can continue to change over time in long-term relationships. The major longitudinal research studies on married couples, including Huston’s PAlR project (e.g., Huston, Niehuis, & Smith, 2001) and Orbuch’s (e.g., Orbuch, Veroff, Hassan, & Horrocks, 2002) Early Years of Marriage Project, have found that compatibility – or at least its traveling companions -change over years of marriage. Some couples who begin in marital bliss find themselves several years later divorced, or, if still together, in unhappy/incompatible relationships. Such marriages have been described in various ways, including empty-shell, conflict-habituated, and mixed-blessing marriages. A recent study of 1,000 married couples across the U.S. (e.g., Whisman, Beach, & Snyder, 2008) found that 31% of marriages can be classified as “unhappy.”

Furthermore, the assessment of compatibility at any point in time may include both a present focus and a future focus. As noted by Berscheid (1985), people are likely to use the word compatibility not only to refer to whether a pair is presently in harmony, but “are also making some prediction about how likely this state is to endure into the foreseeable future” (p. 145). When insiders and outsiders have different views of the compatibility of a relationship, it may be because they are focused, to different degrees, on the current state versus the predicted state.

For example, personal characteristics that are found to be associated with relationship satisfaction and the other traveling companions of relationship compatibility include agreeableness, emotional stability, extraversion, high self-esteem, and secure attachment style (e

58).” A primary goal of relationship science is, in fact, to make predictions and identify causal conditions that influence important relationship phenomena, such as attraction, satisfaction, and stability (e.g., Kelley et al., 1983). As is true of any complex relationship construct that is likely to have reciprocal associations with other relationship phenomena, there are no definitive models or statements that can be offered about which variables are causal conditions of compatibility versus are outcomes or indicators of compatibility. However, Figure 1 provides a summary of the types of variables likely to influence the interaction patterns in relationships that result in compatibility. These causal factors can affect a pair’s current compatibility as well as the likelihood that the relationship will be compatible in the long-run.

The causal conditions are divided into personal, relational, and environmental factors (Kelley et al., 1983). Personal causal conditions are the relatively stable characteristics of the partners in the relationship, who I will abbreviate as P (Person) and O (Other), following the notation used by Kelley et al. (1983). Individuals with a high level of certain personal characteristics are more likely than their counterparts who are characterized by a low level of these traits, to have compatible relationships with others. g., Barelds, 2005). Conversely, the personality characteristics, neuroticism and insecure attachment style, have been linked to lower quality relationships (C; Karney & Bradbury, 1997; Kelly & Conley, 1987).