Cohabitation as an Evolving Process

One of the most important conclusions drawn from recent cohabitation research is that, rather being an endpoint of relationship development (as it was thought to be when cohabitation was considered a substitute for marriage), for many cohabitation is a midpoint of relationship development. Sassler (2004), for example, concluded that quantitative studies have overestimated plans to marry among cohabitors, and argued that commitment continues to grow during cohabitation for many partners. Consequently, cohabitation might be best thought of as an evolving process in which daters’ movement into and out of full-time, shared residential cohabitation is likely to be fluid and change as the relationship becomes more or less involved. Thus, the way cohabitation fits into the progression of dating relationships is complex, varying across couples, occurring at different stages in the relationship, and evolving in nature throughout a relationship.

In a study of noncohabiting and cohabiting daters, Priem and Surra (2011) found evidence suggesting that cohabitation while dating may be a developmental progression that parallels depth of involvement and increases in commitment to wed. These researchers examined various degrees of cohabitation while dating, including noncohabiting, quasi-cohabiting (individuals who reported living together, but maintaining separate residences), and full-time cohabiting. Results showed that increased degrees of cohabitation were associated with greater levels of involvement. Whereas most of the noncohabitors were in casual or serious dating relationships, the majority of quasi-cohabitors was seriously dating or privately committed to wed. This finding suggests that the transition from noncohabiting to part-time cohabitation may be prompted by an increase in stage of involvement from casual to serious dating. As partners become more involved, they begin to cohabit to a greater degree. Thus, cohabitation in dating relationships may be the cause or effect of increasing feelings of closeness and commitment in the relationship.

Priem and Surra (2011) also found that the degree of cohabitation was associated with differences in reports of commitment to wed. On average, noncohabitors reported a 54 percent chance of marrying their dating partners in the future; quasi-cohabitors, 65 percent; and cohabitors, 78 percent. For all three cohabitation statuses, initial chance of marriage was less when the stage of involvement was lower (e.g., casual, serious, privately committed to wed, or formally engaged). These findings further reinforce the idea that cohabitation, in this sample, evolved with growing commitment to the relationship. The results also indicate that cohabitation has the ability to influence the development of commitment to marry. To the extent that cohabitors are not certain that they will marry their partners, the experience of living together has the potential to either increase or decrease commitment to wed. Overall, the findings suggest that cohabitation may form a developmental progression that often maps well onto the development of the relationship itself.

Forms and Functions of Cohabitation While Dating

Another conclusion that can be drawn from current research is that cohabitation has different forms and functions. Form refers to the type of relationship and function refers to the tasks that the relationship performs or the provisions provided by the relationship. Two major forms of cohabitation while dating can be distinguished by the relative certainty of marriage. Each form is associated with unique functions that elucidate the various ways in which cohabitation and relationship development are interrelated.

One prominent form of cohabitation while dating is cohabitation as a prelude to marriage. In this case, cohabitation occurs when partners are seriously committed to one another or engaged formally. According to Casper and Bianchi (2002), cohabitation as a precursor to marriage was characteristic of cohabitors who have definite plans to marry and a low probability of relationship dissolution. For these individuals, cohabitation functions as an advanced stage of involvement with well-established commitment.

Another prominent form is that of cohabitation as dating. In this case, cohabitations appear to be more dating-like, in the sense that they occur earlier in the relationship and prior to the solidification of marriage or future plans. The characteristics of cohabiting relationships, in general, provide evidence that many cohabitations are entered into as part of the dating process. Like many dating relationships, cohabitating relationships tend to be rather short-lived with most ending in either termination or marriage within a few years. About 50 percent of cohabitations last a year or less and only about 10 percent last five years or more (Lichter & Qian, 2008). Moreover, the rate of dissolution of cohabitations formed by age 24 is about 52 percent (Schoen et al., 2007). For these individuals, cohabitation may serve a mate-selection function through which individuals enjoy the companionship and convenience of living together while still evaluating the suitability of their match.

Although these two forms do not encompass all cohabiting relationships, the majority of cohabiting relationships occur either as part of the mate selection process or as a prelude to marriage, rather than a substitute or alternative to marriage. Research has shown that cohabitation functions as a substitute or alternative to marriage for only about 10 percent of cohabitors (Casper & Bianchi, 2002), and they do so particularly for individuals of lower socioeconomic status (Seltzer, 2000), African Americans (Oppenheimer, 2003), and older cohabitors (King & Scott, 2005).

The different forms and functions of cohabitation have the ability to affect how relationships develops and may differentially affect or reflect relationship characteristics such as satisfaction, commitment, and relationship quality and outcomes. This is especially true for individuals who cohabit prior to the solidification of commitment. In the next section, we draw on empirical evidence and theory to understand some of the ways in which cohabitation while dating, compared to dating without cohabiting, may alter relationship development.

Cohabitation and Commitment

The concept of inertia, based on commitment theories, provides an explanation for why cohabitation prior to the solidification of commitment may negatively influence later relationship quality (Stanley, Rhoades, & Markman, 2006). Stanley et al. argued that partners who live together before making a mutual decision to marry are at greater risk for marital distress because the additional constraints accrued during cohabitation promote relationship continuance regardless of dedication to the relationship. Once in a cohabiting relationship, daters engage in activities, such as sharing a lease, buying household items together, or owning a pet, that noncohabiting daters are less likely to experience. In turn, these activities increase constraints to ending the relationship regardless of cohabitors’ level of personal dedication. Such cohabitors are vulnerable to the inertia effect, in which couples who would not have married end up married partly because the constraints of co-residence made leaving the relationship more difficult. Because in these cases the transition to marriage is based on constraint commitment, rather than personal dedication to the relationship, couples are more prone to later marital instability.

Consistent with this perspective, Kline et al. (2004) reported that, compared to those who cohabited after being engaged, individuals who cohabited prior to being engaged had more negative interactions and lower relationship commitment, quality, and confidence. The authors argued that the results are evidence that individuals who live together before they are engaged, a step in relationships that requires explicit commitment to the relationship, are at greater risk for negative outcomes later in their relationship.

While the theory of inertia suggests that constraints may force partners’ into commitments in the absence of dedication, other data suggest that happiness, conflict, and other measures indicative of dedication to the relationship are factors that cohabiting partners weigh when deciding to wed or end the relationship. Brown (2000) found that cohabitors’ transition to marriage was predicted by relationship happiness. Furthermore, negative relationship assessments, including low happiness, interaction, and conflict resolution and high disagreements, prompted cohabiting women to leave the relationship and cohabiting men to refrain from marriage. The results suggest that relationship progression from cohabitation to marriage is a function of individuals’ satisfaction with the relationship, one component of dedication commitment, rather than simply due to constraints.

Cohabitation and Interdependence

Interdependence theory provides an alternative explanation for how cohabitation may positively or negatively impact commitment and relationship quality. Interdependence between partners results from the behavioral interconnections that they weave between them (Kelley et al., 1983). More diverse, frequent, and strong interconnections are associated with greater interdependence and a closer relationship. Living together while dating, compared to dating without cohabiting, undoubtedly enhances partners’ interdependence. The mere fact of sharing a residence engenders greater socio-emotional and instrumental interconnections, thereby increasing both the frequency and diversity of interconnections. Sharing a residence means that partners are in closer proximity than they would be otherwise, and opportunities for coordinating and exchanging joint behaviors are increased. As a result, one partner's behavior is likely to have greater impact on the other, increasing the strength of interconnections. The greater interdependence provides opportunities for couples to get to know each other, and creates a need to coordinate routines in ways that are mutually beneficial if the relationship is to succeed.

While the experience of living together is apt to facilitate increased interdependence, the effect on relational quality is unpredictable. On the one hand, greater interdependence may increase commitment and relational quality as partners discover their compatibilities and each derives rewards from their enhanced interconnectedness. On the other hand, cohabiting may highlight incompatibilities that individuals were previously unaware of, leading to decreased commitment and relational quality.

Examples from Surra's unpublished data from a study of commitment in dating couples illustrate the ways in which the ability to adapt to the new living arrangements influence individuals’ perceptions of relationship quality. In Surra's sample, cohabitation was mentioned as a reason for both increases and decreases in the chance of marriage to a partner. Some participants discussed how learning to live with their partners increased the chance of marriage because they realized they successfully live together. One participant stated:

Moving in together was what caused it [the chance of marriage] to go up. The joint responsibilities of maintaining a place together and doing shopping together and all that kind of stuff, that goes along with, a person living. It was just kind of very worldly type stuff that we did together and did together fairly well.

Another woman discussed how living together increased the chance of marriage because it allowed the partners to get to know each other and reinforced the couple's compatibility:

We moved in together, and he found out that I can't cook or clean, and he's still there, and we've almost killed each other a number of times, but we always work it out. I was very concerned that I would never be able to live with anybody, but, we found out that we are compatible, as far as living together goes, more than we thought, and, that we're both OK with it.

In other cases, the decision decreased the chance of marriage significantly because the inability to adapt to the new living situation was a sign that partners could not or should not get married in the future. One participant stated:

In the five months we lived together, to me it was extremely apparent that I was more willing to adapt to his style of life than he was to adapt to my style. I began to feel very put upon, almost as if I were a maid instead of a partner, and so at that point my feelings of having a marriage with him decreased.

Thus, while cohabitation is apt to have a strong impact on interdependence, its impact on relational quality is likely to depend on a host of other considerations beyond the fact of cohabitation itself. Given that cohabitation occurs at various levels of commitment in dating relationships and the theoretical claims that it has the potential to alter characteristics of the relationship, the question then becomes, how does cohabitation influence relationship development and quality? For example, how can cohabitors foster greater dedication commitment and reduce the potentially harmful effects of inertia? What strategies can cohabitors use to effectively manage the transition to co-residence and building interdependence? Answering these questions requires an understanding of the mechanisms and processes through which commitment, and relationship quality more generally, is built. In the next section, we use cohabitation research to identify key mechanisms through which the experience of cohabiting may influence relationship quality. We then take a communication perspective to explicate crucial insights into the effects of cohabitation on adaptive relationship development.

Sliding Versus Deciding and the Importance of Communication in the Decision-Making Process

According to cohabitation research, one mechanism through which living with a dating partner may exert influence on relationship quality is through a lack of discussion about the decision to cohabit. A budding line of research has begun to examine how the process of deciding to live together might influence relationship development. Cohabitation research from the 1970s (e.g., Macklin, 1978), illustrated that the transition to cohabitation is a “ gradual, often unconscious, escalation of emotional and physical involvement” (p. 6). More recent descriptions focus on the degree to which the decision was “deliberate and purposeful” (Manning & Smock, 2005, p. 990). In a qualitative study about how to measure cohabitation, Manning and Smock reported that when asked how they started to live together, approximately 53 percent of participants did not describe the decision as planned. Instead, these participants described a slide into cohabitation that occurred slowly over time, without specific discussions about the implications. Participants stated, “It just happened,” or “It just snuck up on me.” Manning and Smock concluded that cohabitation is a state into which individuals slide rather than thoughtfully decide. Based on this research, Stanley et al. (2006) coined the term “sliding versus deciding” to describe the gradual progression into cohabitation. The assumption that arose from this line of research is that couples who “slid” into cohabitation moved in together without discussing or thinking about what the transition meant, whereas those who “decided” made the transition after discussing the new arrangement.

Although not yet empirically tested, the theory offers a variety of ways in which the decision-making process may influence relationship development and quality. Stanley et al. (2006) proposed that sliding into cohabitation without fully considering the implications of the decision increases individuals’ risk for later distress due to inertia. From this perspective, discussing what the transition to co-residence means to each person and for the future of the relationship is a crucial component in the success of cohabiting relationships.

Communication research provides insight into how the decision-making process may influence the relationship quality and future outcomes of cohabitors. As currently conceptualized, sliding inherently involves a lack of communication. To the extent that individuals are deliberately avoiding discussion about the transition to co-residence, previous research on topic avoidance, or the strategic decision not to disclose information, may shed light on the detrimental effects of sliding. Research has shown that individuals avoid certain topics, such as the state of the relationship, relational rules, and negative self-disclosures, because they are considered taboo (Baxter & Wilmot, 1985) or because they are trying to protect the self or the relationship (Afifi & Guerrero, 2000). Daters may choose not to discuss the decision to cohabit for fear that the discussion will negatively impact the relationship, or out of a desire to maintain the status quo and avoid disclosing information that is face threatening. Living together may be particularly difficult to discuss because it requires a change in the status of the relationship, something that may be threatening when involvement is ambiguous, fluid, or unknown. Even in an established or committed relationship, cohabitation implies movement to a new level and it may be safer to avoid discussion of what that movement entails. Topic avoidance may reinforce relational uncertainty, leading to decreased feelings of liking, intimacy and closeness, and increased susceptibility to the negative outcomes associated with relational uncertainty.

In contrast to sliding, deciding is thought to involve active discussion of what living together means. As such, deciding requires disclosure of feelings, which may enhance intimacy and satisfaction with the relationship (Altman & Taylor, 1973). Engaging in a conversation about cohabiting may serve to define the relationship because talk serves to “project an image of the relationship as real and enduring, thereby promoting its continuance” (Sillars & Vangelisti, 2006, p. 335). Deliberations about the transition to co-residence have the potential to alter partners’ perception of the relationship and their behavior toward each other. Relationship talk, including conversations about the transition to co-residence, can serve to maintain or change the relationship between individuals by influencing people's definition of the relationship and clarifying how committed or attached partners are (Baxter, 1987); however, it can also cause greater uncertainty and stress. In the context of cohabitation, conversations about moving in together may affirm the meaning of the relationship and assist in the construction of a unique relationship identity that facilitates relationship growth. Alternatively, partners may discover that their definitions of the relationship differ significantly, leading to distress and possibly dissolution.

One of the issues that future research must address to understand fully how sliding versus deciding influences the development of cohabiting relationships is how partners can manage the discussion about living together and what communication strategies are most effective in those interactions. Before pursuing this line of research, however, the first step for scholars will be to strengthen the conceptual definition of sliding versus deciding. Because sliding is a relatively new insight, the construct lacks a clear definition. First, the necessity of communication is unclear in current conceptualizations of sliding. For example, is sliding the gradual progression that cohabitors describe, starting with spending a lot of time together, to sleeping over more and more, and finally moving into a single residence; or is sliding solely a function of the lack of discussion about the implications of moving in together? Defining sliding in terms of the degree to which it is deliberate and purposeful suggests that deciding may be a function of either the discussion of what the transition means or careful thought about what the transition means. Thus, it is possible that people “slide” into cohabitation without discussing the transition with their partner, but having fully thought through the implications of moving in together. Further distinguishing the characteristics of sliding versus deciding would allow researchers to examine what intra-personal thought processes individuals engage in, if deliberate thought is sufficient for positive future relationship outcomes, and what communication strategies are most effective.

Ambiguity and Relational Uncertainty in Cohabiting Unions

Another mechanism through which the experience of cohabiting may influence the adaptive development of dating relationships is based on the ambiguity of cohabiting unions and the resulting relational uncertainty cohabitors endure. An abundance of research has described cohabitation as an uninstitutionalized union in the U.S.A. (see Cherlin, 2004). Compared to marriage, which is governed by consensual norms and formal laws, and dating, which has progressive relational scripts that provide clarity about the path a couple is on (Whitehead, 2002), cohabitation remains an incomplete institution (Nock, 1995). Due to the lack of institutionalization, cohabitation represents an ambiguous state that is devoid of socially accepted expectations and clear norms for what the transition means about commitment, especially for those who cohabit prior to engagement. Cohabitors are even unclear about what label to apply to their partner, presumably because of the lack of a language to describe the state of cohabiting relationships (Manning & Smock, 2005).

The ambiguity of some forms of cohabitation makes uncertainty reduction theory a relevant framework for understanding how cohabitation may influence adaptive and maladaptive relationship development. In ongoing relationships, transitions into cohabitation may influence people's relational uncertainty, which is the degree of confidence people have in their perceptions of involvement in a relationship (for review see Knobloch & Solomon, 1999). Uncertainty reduction theory posits that uncertainty is a subjective, aversive state that stems from individuals’ awareness of ambiguity and an inability to predict and explain behavior (see Knobloch, 2008). The ambiguity surrounding the institution of cohabitation may lead to dyadic and individual relational uncertainty.

One study of college-aged cohabitors found that the majority of cohabitors do, in fact, experience relational uncertainty that stems from a number of sources. When asked to describe issues of relational uncertainty experienced in their cohabiting relationships, 93 percent of the 180 cohabitors sampled reported at least one relational uncertainty (Steuber & Priem, 2011). The sources of relational uncertainty documented ranged from relational sustainability and compatibility to doubts about finances, family planning, and communication. A substantial number of cohabitors referenced questions about relational norms and relational steps, which included doubts about whether participants or their partners were ready for marriage or if the relationship would progress toward marriage. Cohabitors also expressed doubts about expectations for financial responsibilities, housework, and how much time the couple should spend together.

Scholars have argued that the ambiguity surrounding the transition to cohabitation and the subsequent relational uncertainty may undermine mutual clarity about the nature of the relationship, which may, in turn, inhibit the development of a stable and committed union (Stanley et al., 2006). Communication research on relational uncertainty highlights the ways in which ambiguity and relational uncertainty in cohabiting relationships may deter adaptive relationship development in multiple ways. First, relational uncertainty enhances negative reactivity and hinders message processing. Relational uncertainty is associated with more intense experiences of negative emotions, including anger, sadness, fear, and hurt (Knobloch & Solomon, 2002, 2003). Furthermore, individuals’ who experienced relational uncertainty reported more jealousy, which is associated with reduced intimacy in the relationship (Theiss & Solomon, 2008).

In addition, individuals who are unsure about their relationship lack well-defined expectations for behavior, which makes message processing more difficult. For example, relational uncertainty is associated with a decreased ability to interpret cues of intimacy and liking during interactions (Knobloch & Solomon, 2005), and may make people more critical of the messages they receive from a dating partner (Knobloch, Miller, Bond, & Mannone, 2007). Consistent with this claim, Priem and Solomon (2011a) found that individuals who reported greater partner uncertainty experienced slower recovery in the stress hormone cortisol after a supportive interaction with a dating partner, suggesting that relational uncertainty reduces the ability to capitalize on the potential stress reducing benefit of supportive messages.

Such research suggests that cohabitation prior to establishing commitment may be problematic for adaptive relationship development. The inherent ambiguity may be a catalyst for relational uncertainty, which may undermine relationship quality by enhancing negative reactions to relationship events and undercutting message processing. To the extent that relational uncertainty is a key factor in understanding the development of, and outcomes associated with, cohabitation, a crucial question for scholars to address in future research is how cohabitors manage uncertainty in ways that facilitate positive relationship development. According to uncertainty reduction theory, people seek information to reduce uncertainty, which should, in turn, enhance intimacy, liking, and similarity between partners (Berger & Calabrese, 1975). Thus, a promising line of research may be in the examination of information seeking and strategies that effectively reduce relational uncertainty.

Adapting to Co-residence and Overcoming Relational Turbulence

As discussed earlier, cohabitation is a relationship transition that requires individuals to adapt to changing levels of interdependence. Thus, partners’ ability to negotiate the increasing levels of interference that stem from cohabitation may be another key mechanism for understanding how living together exerts negative or positive effects on relationship quality.

The relational turbulence model (RTM) provides a potentially advantageous framework for understanding how partners might navigate the demands of increased interdependence. According to RTM, transitions create a need to adapt to the changing interdependence, or mutually beneficial systems of behavior, in order to sustain the relationship. As couples negotiate interdependence, attempts to coordinate action sequences inevitably lead to interference, or cases where a partner's involvement makes achieving goals more difficult. The increased interference leads to relational turbulence, which is associated with intensified subjectivity wherein individuals tend to be more cognitively, emotionally, and behaviorally reactive to relationship events (for full review see Solomon & Knobloch, 2004).

One study of the RTM and perceptions of emotional support provides insight into the ways in which interference and relational turbulence may have both positive and negative effects on relationship outcomes. Priem and Solomon (2011b) found that interference was associated with both more positive and more negative perceptions of a dating partner's supportiveness. Participants who reported greater interference from their partner reported greater relational turbulence, which in turn, predicted more positive evaluations of a partner's supportive messages. Interference, however, was also directly associated with more negative evaluations of a partner's supportiveness. These results suggest that there is something unique about the ways in which a partner's hindering the accomplishment of daily tasks influences perception. On the one hand, a partner's interference causes people to feel that their relationship is stressful, which polarizes their reactions to relationship events making positive situations more positive and negative situations more negative. In the context of supportive messages, then, interference positively impacts perception. On the other hand, the direct effect of interference on perceptions of supportiveness indicates that things going on in the relationship also negatively influence how subsequent supportive interactions are perceived.

An implication of this line of research for cohabitors is that couples who are able to renegotiate interdependence and work through the turbulence associated with the transition to co-residence may reap the benefit of a stronger relationship in the future. As daters begin living together, they experience increased interference and relational turbulence that alters their perception of relationship events in negative and positive ways. Consistent with previous research, interference may make cohabitors more reactive to negative events, such as perceiving irritations as more severe and relationally threatening (Solomon & Knobloch, 2004), which over time may erode the quality of the relationship. In contrast, the ability to work through the changes affirms partners’ ability to work together to solve life's problems and provide mutual support, thereby reducing uncertainty and reinforcing commitment to the relationship. As cohabitation becomes more normative, future research should identify ineffective strategies for dealing with interference that are associated with decreased relationship quality and examine how couples can manage the transition to cohabitation in a way that bolsters positive relationship development.

Addressing Measurement Issues Cohabitation Research

One of the most important methodological issues is how to measure cohabitation. The perspective of cohabitation as a status, rather than a process, has created a body of research that utilizes a binary response question to measure cohabitation. For example, one of the major national surveys, the National Survey of Family Growth (NSFG) used the question, “Have you ever lived with someone whom you did not later marry?” to measure cohabitation status. Binary questions, such as this one, are problematic because they over simplify the cohabitation process and overlook the fact that for many, cohabitation develops gradually over time.

Given the diversity in the cohabitation experience, scholars have begun to acknowledge that broader definitions of cohabitation should be used to understand its role in relationship development (Knab & McLanahan, 2007; Manning & Smock, 2005). Previous research provides insight into ways in which researchers may effectively measure cohabitation. Quotations in Manning and Smock's (2005) article show that participants had a difficult time identifying when they started to cohabit, but could distinguish between when the partner moved in full-time versus when the partner stayed over every night. This suggests that even though cohabitation often occurs gradually and, therefore, lacks a clear start, the transition from part-time cohabitation to full-time cohabitation in a shared residence is meaningful. Thus, maintaining separate residences or living in a shared residence is a distinguishing feature for cohabitors that can be used when measuring cohabitation.

Other research has endorsed the use of subjective and behavioral measures to capture more fully the cohabitation experience (see Knab & McLanahan, 2007). The Fragile Families survey, for example, includes a more objective question, “How many nights per week do you spend the night together?” and a more subjective categorical question, “Are you and—living together?” with options being “all/most of the time,” “some of the time,” “rarely,” or “never.”

Priem and Surra (2011) also used a method of measuring cohabitation while dating that provides greater nuance. Participants were asked to choose one of five categorical options provided that best described the status of their relationship. From that data, the authors created three groups: noncohabitors, quasi-cohabitors, and cohabitors. Individuals who reported they were dating and living in separate residences were labeled as noncohabitors. The term quasi-cohabitor was used for participants who reported either “living together 3–4 nights, but keeping separate residences,” or “living together every night, but keeping separate residences.” Cohabitors included individuals who reported “living together with both partners’ possessions in one residence.” This method of measuring cohabitation retains the assumption that a central distinguishing factor in cohabitation is the sharing of a residence, and makes a distinction between those living together part of the time and not at all.

Embracing Repeated Measurement and Diversity in Sampling to Study Cohabitation

As noted previously, most research on cohabitation has come from large-scale surveys with national representative samples. Commenting on the limited set of methods used to study cohabitation, Stanley et al. (2006) lamented “the fact that a vast number of studies published on the cohabitation effect are from a single, now aging data set (the National Survey of Families and Households)” and the “general dearth of longitudinal methods with sufficient sensitivity and quality of measurement” (pp. 499–500). While communication scholars have much to offer the study of cohabitation theoretically, the methods used to study it will be demanding. The study of cohabitation and its role in relationship development is best achieved by means of repeated measurement of diverse samples of cohabiting individuals at different levels of involvement. As we have demonstrated, cohabitation is a fluid state, something that typically develops gradually and that individuals enter in steps, with occasional falls backwards, before living together full-time in one residence. Because of the fluid nature of cohabitation and its uncertain place in relationship development, studies are needed in which frequent, repeated measurements are taken to match assessments of quality against changes in cohabitation or the evolution of decisions to begin or end cohabitations.

Likewise, sampling will be challenging in the study of cohabitation. One advantage of large national surveys is that they make it possible to tease out the diverse forms and functions of cohabitation in different subpopulations. Such surveys have consistently shown that cohabitation varies greatly by race, immigrant status, social class, and other variables (for a review see Greenland & Smock, in press). Yet the large majority of research on dating relies almost exclusively on college-student samples or samples in which the characteristics of the partners are not described (Surra et al., 2007). In the context of cohabitation, reliance on a college-student sample is less desirable because the effects associated with cohabitation are known to vary by demographic characteristics. In order to study cohabitation, communication scholars will need to use samples more broadly selected from the community-at-large.

Evolving as a Key for Future Research

As noted previously, American views and their practice of cohabitation have changed drastically. As cohabitation becomes more institutionalized, norms surrounding it will develop, and the associations between cohabitation and relationship outcomes will change. These changes will require that scholars’ thinking about, and research on, cohabitation also evolve.

One way that research on cohabitation can evolve is by acknowledging the changing nature of cohabitation and building from previous research and theory in new cohorts and samples. Research surrounding the cohabitation effect highlights the need for testing old assumptions with new data. Although it seemed as though the negative effects of cohabitation on marriage were undeniable in early research on cohabitation, the rapid changes in cohabitation has led scholars to question the relevance of the cohabitation effect in contemporary relationships. Smock (2000) stated that newer findings provide, “strong indications that cohabitation is changing,” and that “the inverse relationship between premarital cohabitation and marital stability is diminishing. The effect, if any, is trivial for recent birth cohorts” (p. 13), For example, Teachman (2003) found that for women, cohabiting with their future spouse is not associated with a higher risk of marital dissolution. Schoen (1992) found that the negative association between cohabitation and marital stability largely disappears as cohabitation becomes increasingly common.

Regardless of whether or not the cohabitation effect is weakening in more recent cohorts (a fact that remains highly debated), the shifts in findings underscore one of the most important points for future research. Trends in cohabitation continue to change. As cohabitation while dating reaches normative status, it will become more institutionalized. Researchers must continue to test old assumptions using new data to keep up with changing trends. This includes not only using new analysis techniques and sampling from a diverse range of groups, as discussed earlier, but also being aware of the assumptions that have been made in early research and testing the validity of old assumptions with more recent cohorts of cohabitors.