What Fantasies Can Do to Your Relationship: The Effects of Sexual Fantasies on Couple Interactions

Transcription

1 789611PSPXXX / Personality and Social Psychology BulletinBirnbaum et al. research-article2018 Empirical Research Paper What Fantasies Can Do to Your Relationship: The Effects of Sexual Fantasies on Couple Interactions Personality and Social Psychology Bulletin by the Society for Personality and Social Psychology, Inc Article reuse guidelines: sagepub.com/journals-permissions DOI: pspb.sagepub.com Gurit E. Birnbaum 1, Yaniv Kanat-Maymon 1, Moran Mizrahi 1, May Recanati 1, and Romy Orr 1 Abstract Research addressing the underlying functions of sexual fantasies has mainly focused on variables associated with frequency and content of fantasies. Relatively less is known about how sexual fantasizing affects the relationship. Four studies examined the contribution of fantasizing about one s partner ( dyadic fantasies ) to relationship outcomes. In Studies 1 and 2, participants fantasized either about their partner or about someone else and rated their desire to engage in sex and other nonsexual relationship-promoting activities with their partner. In Studies 3 and 4, romantic partners recorded their fantasies and relationship interactions each evening for a period of 21 and 42 days, respectively. In Study 4, partners also provided daily reports on relationship perceptions. Overall, dyadic fantasizing was associated with heightened desire and increased engagement in relationship-promoting behaviors. Relationship perceptions explained the link between dyadic fantasies and relationship-promoting behaviors, suggesting that such fantasies benefit the relationship by enhancing partner and relationship appeal. Keywords extradyadic, fantasies, relationship quality, sexual desire, sexuality Received December 2, 2017; revision accepted June 23, 2018 Sexual desire is among the strongest forces in human nature, one that can induce ecstatic pleasure and profound connection (Birnbaum & Finkel, 2015; Birnbaum, Mikulincer, Szepsenwol, Shaver, & Mizrahi, 2014). Unfortunately, desire tends to diminish gradually over time when the novelty and mystery that fuel it fade away (e.g., Birnbaum, Cohen, & Wertheimer, 2007; McNulty, Wenner, & Fisher, 2016). A decrease in frequency of sexual fantasies about existing partners ( dyadic fantasies ) and an increase of frequency of fantasies about other people ( extradyadic fantasies ) are typical manifestations of this process (Hicks & Leitenberg, 2001), as partners seek other sources of novelty and variety, at least in the fantasy realm. These fantasies may satisfy the need for novelty and variety without threatening the relationship. Still, some of them may make relationship deficiencies more salient, leading to further relationship dissatisfaction. Surprisingly, research addressing the underlying functions of sexual fantasies has mainly focused on variables associated with frequency and content of sexual fantasy (see Leitenberg & Henning, 1995; Ziegler & Conley, 2016, for reviews). Relatively less is known about how sexual fantasizing affects the relationship. Scholars did acknowledge that the use of fantasies might act as an aphrodisiac that increases sexual desire (e.g., Newbury, Hayter, Wylie, & Riddell, 2012; Trudel et al., 2001). However, the relevant literature has been largely based on clinical impressions rather than systematic research and offered conflicting views about whether and why fantasies training (i.e., guiding partners to generate arousing sexual imagery) promotes relationship well-being (Newbury et al., 2012). To address these concerns, the present research relied on complementary methods while examining the contribution of dyadic and extradyadic sexual fantasies to relationship outcomes as well as the mechanisms underlying this connection. Sexual Fantasies and Their Underlying Functions Sexual fantasies are experienced privately in an imaginary world. And yet, these fantasies do not exist in a relationship 1 Interdisciplinary Center Herzliya, Israel Corresponding Author: Gurit E. Birnbaum, Baruch Ivcher School of Psychology, Interdisciplinary Center Herzliya, P.O. Box 167, Herzliya 46150, Israel. birnbag@gmail.com

2 2 Personality and Social Psychology Bulletin 00(0) vacuum; the quality of interactions between partners can affect their content and frequency (Birnbaum, Mikulincer, & Gillath, 2011; Birnbaum, Svitelman, Bar-Shalom, & Porat, 2008) as much as the fantasies themselves may affect the relationship. Scholars exploring the nature of fantasies, however, tend to disagree as to whether sexual fantasies compensate for relational and sexual deficiencies (Leitenberg & Henning, 1995). In support of the compensatory view of fantasies, research has demonstrated that people habitually use mental imagery to regulate stress by creating an alternative reality (e.g., being in a powerful position). This alternative reality may counteract the initial stress-provoking event and restore the threatened self-esteem (e.g., Harder et al., 1984; Zelin et al., 1983). Nevertheless, studies that have focused specifically on sexual themes challenged the compensatory view, showing that sexual difficulties are associated with low rather than with high frequency of fantasizing (e.g., Arndt, Foehl, & Good, 1985; Lentz & Zeiss, 1983). Still, both frequency and content of sexual fantasizing may compensate for overall relational distress rather than for sexual dissatisfaction per se. This possibility is corroborated by studies showing that, compared with happily married people, people in distressed marriages fantasize more frequently about sexual themes and particularly about extradyadic sex (Davidson & Hoffman, 1986; Trudel, 2002), possibly making up for relationship burnout. Other studies, though, yielded conflicting results about the association between relationship satisfaction and frequency of sexual fantasies. In one of these studies, for example, frequent sexual fantasizing was associated with relationship dissatisfaction in men, but with sexual satisfaction in women (e.g., Alfonso, Allison, & Dunn, 1992). These inconsistencies are difficult to resolve due to methodological problems in past studies, such as correlational designs that preclude conclusions about causal connections between fantasizing and relationship quality. For example, it is not clear whether relationship difficulties encourage extradyadic fantasizing or whether extradyadic fantasizing contributes to relationship dissatisfaction. Regardless of whether sexual fantasies emanate from relationship difficulties, most scholars agree that fantasies are typically used to promote sexual arousal and enjoyment (Newbury et al., 2012; Ziegler & Conley, 2016). To be sure, more frequent fantasizing is associated with more frequent orgasms as well as greater sexual desire, arousal, and satisfaction (Leitenberg & Henning, 1995; Purifoy, Grodsky, & Giambra, 1992). Relying on the potential beneficial effects of fantasies, therapists often use fantasy training in the treatment of couples with sexual dysfunctions, claiming that fantasies can promote couple intimacy and improve sexual functioning. More specifically, they argue that sexual imagination offers mental alternatives to current discomfort that facilitates planning of a positive future course of action (Newbury et al., 2012; Person, 1996). This approach is echoed in more general research on the relational benefits of social daydreaming (see review by Poerio & Smallwood, 2016). Specifically, daydreams about interacting with close others have been found to increase feelings of love and connection for them that presumably foster pleasant future interactions. This effect was particularly pronounced in participants who scored low on these feelings before daydreaming (Poerio, Totterdell, Emerson, & Miles, 2015), suggesting that engaging in constructive forms of offline social cognition regulates negative social emotions and facilitates the pursuit of relationship-promoting goals (Poerio & Smallwood, 2016). Indeed, reflecting on how other people think, feel, and behave during daydreaming may enhance empathetic understanding (Decety & Jackson, 2006) and translate into responsive interpersonal behavior (Poerio & Smallwood, 2016), which is essential to maintaining intimate relationships (Birnbaum et al., 2016). In this sense, the functional significance of sexual fantasies may be similar to that of nonsexual mental imagery. Research on nostalgic reverie, for example, has indicated that sentimental longing for one s past fosters feelings of social connectedness (e.g., experiencing less relationship insecurity as well as feeling more loved, protected, and socially supported) and facilitates approach-oriented behavior (e.g., wishing to interact with others, showing empathy, seeking physical proximity; see review by Sedikides & Wildschut, 2018). Sexual fantasizing may thus be a specific form of mental imagery that serves a similar function of coping with an unpleasant reality (e.g., relationships that are no longer exciting in the case of sexual fantasies and homesickness in the case of nostalgic reverie). Unfortunately, no research has thus far investigated the relationship consequences of either dyadic or extradyadic fantasizing. This lack of research is surprising, given that although people do not necessarily act on their desires or even interested in carrying them out (e.g., Critelli & Bivona, 2008), sexual fantasies may lead to action with real-life consequences (Stockwell & Moran, 2014). For example, participants who had undergone sexual fantasy induction were more likely than participants in a control group to report higher levels of sexual behaviors 1 week after the experimental manipulations (Eisenman, 1982). Several studies have indicated that fantasizing about certain sexual themes may encourage the enactment of corresponding sexual behavior (e.g., Eisenman, 1982; Visser, DeBow, Pozzebon, Boegart, & Book, 2015). Nevertheless, the contribution of fantasies to relationship-based behaviors has not been examined yet. Most of the studies that did associate sexual fantasizing with relationship outcomes focused on global perceptions of relationship satisfaction instead of assessing specific behavioral aspects of the relationship (e.g., Alfonso et al., 1992; Davidson & Hoffman, 1986). Moreover, these studies used one-time, retrospective surveys and did not examine the dynamic interplay of fantasizing and relationship perceptions in their natural context, thereby overlooking important sources of variability (e.g., fluctuations in the quality of couple interactions). The methodological limitations of

3 Birnbaum et al. 3 these studies preclude drawing valid conclusions as to whether and why dyadic and extradyadic sexual fantasizing affects the relationship with current partners. Putting sexual fantasies within a relational context may therefore shed light on how fantasizing influences the relationship dynamics and elucidate the psychological mechanisms that regulate the behavioral expressions of sexuality in romantic relationships. The Present Research The present research sought to deepen the current understanding of whether and why sexual fantasizing affects sexual and nonsexual relationship outcomes. Building on the idea that the sexual system evolved to promote enduring bonds between romantic partners by eliciting relationshippromoting tendencies (Birnbaum, 2018; Birnbaum & Finkel, 2015), we predicted that activation of the sexual system through dyadic fantasizing would yield beneficial effects on sexual and nonsexual relationship outcomes. Prior research has already demonstrated that gratifying sex facilitates engagement in relationship-promoting behaviors (e.g., providing support, expressing love; Birnbaum, Reis, Mikulincer, Gillath, & Orpaz, 2006; Debrot, Meuwly, Muise, Impett, & Schoebi, 2017). Relying on the literature that social daydreaming can serve a relationship-promoting means of achieving feelings of social connection (Poerio & Smallwood, 2016), we examined the possibility that fantasizing about sex with one s partner would have similar effects through enhancing positive relationship perceptions. Specifically, the rewarding aspects of fantasizing might become associated with the partner and the relationship, coloring them in a more appealing light. This improved appeal, in turn, might motivate people to create an even more positive relationship atmosphere by actively engaging in behaviors that help build the relationship. The literature is less conclusive about the potential relational effects of extradyadic fantasizing. In particular, although sexually fantasizing is generally considered favorable for increasing sexual arousal (Leitenberg & Henning, 1995), therapists debate as to whether fantasizing specifically about someone other than the partner proves useful in compensating for relational and sexual difficulties and in heightening desire for the current partner (Newbury et al., 2012). Some scholars assert that extradyadic fantasies help maintain desire within the context of current relationships by regulating tensions between autonomy and union and increasing the sense of differentiation between partners (Newbury et al., 2012; Schnarch, 1997). Others contend that such fantasies may remove the focus from shared intimacy to individual personal gratification or even be perceived as mental infidelity (Kahr, 2008; Ziegler & Conley, 2016). As such, they may arouse insecurities and have detrimental effects on the relationship (Newbury et al., 2012). Given the current state of the fantasy literature, it is difficult to predict whether extradyadic fantasizing would have beneficial effects on partner and relationship perceptions or whether they would exacerbate relationship difficulties. We therefore made no specific a priori hypotheses regarding the extradyadic fantasies-relationship linkage, beyond hypothesizing that dyadic fantasizing would have more favorable effects on the relationship than extradyadic fantasizing. Four studies employed complementary methodologies to examine the contribution of sexual fantasizing to sexual desire directed toward one s partner and to other nonsexual relationship outcomes. In all studies, participants who were currently involved in a romantic relationship described their fantasies in narrative form or rated their frequency, and then reported on sexual and nonsexual aspects of their relationship. In Study 1, we instructed participants to fantasize either about their partner or about someone else and then to rate their desire for sex and for doing something that would make their partner happy. In Study 2, we crossed the fantasy manipulation used in Study 1 with a second manipulation of nonsexual fantasizing, such that participants from a new sample imagined one of four scenarios that involved engaging in sexual or nonsexual activity with either their partner or someone else. Then, participants rated their desire to have sex and to engage in positive nonsexual activities with their partner. Studies 3 and 4 employed a daily experience methodology to explore whether the expected effects of sexual fantasizing generalized to everyday life and were manifested in actual engagement in relationship-promoting behaviors. Study 4 also investigated the processes by which dyadic fantasizing affected engagement in such behaviors. Specifically, in Studies 3 and 4, we asked both members of romantic couples to complete daily measures of their fantasies and relationship interactions over a span of 23 and 42 consecutive days, respectively. In Study 4, partners also provided daily reports on positive and negative relationship perceptions. In all studies, all data were collected before any analyses were conducted; all data exclusions, manipulations, and variables analyzed are reported. Our specific predictions were as follows: 1. Dyadic fantasizing would have more beneficial effects on sexual and nonsexual aspects of the relationships compared with extradyadic fantasizing. 2. Dyadic fantasizing would be associated with increased desire for sex with one s partner and for engaging in other nonsexual relationship-promoting behaviors. 3. Relationship perceptions would explain the link between dyadic fantasizing and engaging in relationship-promoting behaviors, such that participants would be more likely to perceive their relationship positively and less likely to view them in a negative light following fantasizing about their partner. These perceptions, in turn, would predict engagement in relationship-promoting behaviors.

4 4 Personality and Social Psychology Bulletin 00(0) Study 1 Study 1 was designed to firm up a causal link between dyadic fantasizing and the desire to have sex with one s partner and to engage in relationship-promoting behavior. To do so, we employed an experimental design in which romantically involved participants were provided with a definition of sexual fantasy and were instructed to fantasize sexually about either their partner (a dyadic fantasy condition) or someone else (an extradyadic fantasy condition) and then to describe in narrative form this fantasy. Following this procedure, participants completed a questionnaire indicating their desire to have sex with their partner and their desire to do something that would make their partner happy. Method Participants. Eighty students (40 women, 40 men) from a university in central Israel volunteered for the study. Sample size was determined via a priori power analysis using G*Power software package (Faul, Erdfelder, Buchner, & Lang, 2009) to ensure 80% power to detect effect size, d, of 0.50 at p <.05. This hypothesized effect size was based on the findings of previous research examining the association of relationship insecurity with sexual fantasies (Birnbaum, Simpson, Weisberg, Barnea, & Assulin-Simhon, 2012). Potential participants were included in the sample if they were in a steady heterosexual, monogamous relationship of longer than 4 months (only one member of the couple participated in the study). Participants ranged from 20 to 33 years of age (M = 25.14, SD = 2.64). Relationship length ranged from 4 to 135 months (M = 42.65, SD = 31.71). No significant differences were found between the experimental conditions for any of the sociodemographic variables. Measures and procedure. Participants who agreed to participate in a study of expressions of intimacy were individually scheduled to attend a single half-hour laboratory session. Prior to each session, participants were randomly assigned to one of two conditions: Sexually fantasizing about one s partner or about someone else. Upon arrival at the laboratory, participants were greeted by a research assistant and were presented with the definition of the term sexual fantasy (Leitenberg & Henning, 1995). Then, participants were instructed to fantasize sexually about either their partner (a dyadic fantasy condition) or someone else (an extradyadic fantasy condition). We asked participants to describe in narrative form their fantasy when they had this fantasy in mind. Instructions for the dyadic fantasy condition were adapted from Birnbaum (2007) to reflect a dyadic fantasy: Please think of a sexual fantasy about your current relationship partner and write about the first one that comes to mind in the space below. Please describe in detail the specific scene, series of events, the figures, wishes, sensations, feelings, and thoughts that are experienced by you and the other figures in your fantasy. At this point, we wish to note that you are writing anonymously, so feel free to write anything you like. Instructions for the extradyadic fantasy condition were similar, except that the participants were asked to think of a sexual fantasy about someone who is not their current partner. After describing their fantasy, participants were instructed to think about how they felt right then and to complete three items assessing their sexual desire for their partner (e.g., I feel a great deal of sexual desire for my partner ; I am passionately attracted to my partner ). These items were adapted from the sexual desire scale used by Birnbaum and her colleagues (2016; Study 3) to reflect current experiences of desire. The three items were internally reliable (α =.70) and were thus averaged to form a global sexual desire index. Participants also completed two items assessing their desire to do something that would make their partner happy (e.g., I desire to do something that would make my partner happy ; I desire to do things with my partner that my partner really enjoys ; r =.25, p =.03). These items were intermixed with fillers assessing positive and negative feelings (e.g., I feel relaxed ; I experience negative feelings for my partner ) to mask the nature of these questionnaires. All items were rated on a 7-point Likert-type scale, ranging from 1 (not at all) to 7 (very much). Finally, participants provided demographic information (e.g., age, relationship length) and were then carefully debriefed. Results and Brief Discussion Manipulation check. Two judges independently indicated whether each fantasy involved sexual activity with one s partner or not. Neither of the judges had access to additional information about the participants while the fantasies were being read. All fantasies involved sexual themes in which the actual target of the fantasy matched the instructed one (i.e., one s partner vs. someone else). In addition, a t test for independent samples on negative feelings for current partner did not yield any significant effect (see Table 1), ruling out the possibility that participants experienced more negativity in the extradyadic fantasies condition than in the dyadic fantasies condition. The effects of fantasies on desire and relationship-promoting behavior. T tests for independent samples on the desire to engage in sex with one s partner and on the desire to engage in relationship-promoting behavior yielded the expected effect, such that the desire to engage in these behaviors was greater in the dyadic fantasizing condition than in the extradyadic fantasizing condition (see Table 1). Study 1 demonstrated that dyadic fantasizing is causally responsible for instigating the desire to have sex with one s

5 Birnbaum et al. 5 Table 1. Means, Standard Deviations, Statistics, and Effect Sizes of Desire for Engaging in Sex, Relationship-Promoting Behaviors, and Negative Feelings for the Fantasy Conditions (Study 1). Dyadic fantasies Extradyadic fantasies M SD M SD t(78) Cohen s d 95% CI for Cohen s d Sexual desire * 0.53 [0.08, 0.97] Relationship-promoting * 0.57 [0.13, 1.02] behaviors Negative feelings [ 0.27, 0.61] Note. Items were rated on a 7-point Likert-type scale. CI = confidence interval. *p <.05. partner and to do something that would make this partner happy. These findings suggest that fantasizing about sex with one s partner, even without experiencing such fantasies spontaneously, may increase this partner s sexual appeal and encourage the use of strategies that allow people to get closer to their partners and improve their relationships. This conclusion, however, should be viewed with caution, as it is not clear whether the findings reflect the beneficial effect of dyadic fantasizing on relationship outcomes or the detrimental effect of extradyadic fantasizing. Given that the average levels of desire and relationship-promoting behaviors in the extradyadic fantasies condition were above the midpoint of the scale used, it is also possible that extradyadic fantasizing benefits relationships, although to a lesser degree than dyadic fantasizing. Furthermore, Study 1 cannot rule out the possibility that these desires are enhanced by merely thinking about one s partner regardless of context rather than by fantasizing about this partner sexually. These limitations were addressed in Study 2. Study 2 Study 1 showed that dyadic fantasizing led people to experience greater sexual desire for their partner and greater desire to engage in relationship-promoting behaviors. Study 2 aimed to replicate and extend these findings in a couple of ways. First, we sought to clarify whether the difference in the expressed desires between dyadic and extradyadic fantasy conditions reflects the positive influence of dyadic fantasizing or the negative influence of extradyadic fantasizing. To do so, we added two nonsexual conditions in which participants imagined that they discussed a recent concern either with their partner or with someone else. The inclusion of these control conditions also allowed us to rule out the possibility that merely thinking about one s partner increases the desire for engaging in sex and other relationship-promoting behaviors regardless of context (i.e., sexual vs. nonsexual). Second, we replaced the general measure of relationship-promoting behaviors used in Study 1 with a measure that focused on certain nonsexual shared activities (e.g., engaging in an intimate, nonsexual conversation with one s partner). Specifically, in Study 2, partnered participants imagined one of four scenarios that involved engaging in sexual or nonsexual activity with either their partner or someone who was not their romantic partner. Then, they described this scenario in narrative form and rated their desire to have sex and to engage in positive nonsexual activities with their partner. We hypothesized that participants would experience greater desire to engage in sex and other relationship-promoting behaviors in the dyadic sexual fantasy condition as compared with the other conditions. Method Participants. One hundred two students (53 women, 49 men) from a university in central Israel volunteered for the study. Originally, we sought a similar number of participants per condition as in Study 1, based on a similar power analysis. However, recruitment difficulties led us to end the study prematurely and we decided to analyze and report the data at that stage. Potential participants were included in the sample if they were in a steady heterosexual, monogamous relationship of longer than 4 months. Participants ranged from 20 to 34 years of age (M = 24.89, SD = 2.81). Relationship length ranged from 4 to 209 months (M = 38.69, SD = 32.64). No significant differences were found between the experimental conditions for any of the sociodemographic variables. Measures and procedure. Participants who agreed to participate in a study of expressions of intimacy were individually scheduled to attend a single half-hour laboratory session. Prior to each session, participants were randomly assigned to one of four conditions in a 2 (imagining engaging in sex: partner vs. other) 2 (imagining engaging in a nonsexual interaction: partner vs. other) between-subjects design. Upon arrival at the laboratory, participants were greeted by a research assistant and were asked to imagine themselves in one of these four scenarios. Instructions for the dyadic and extradyadic sexual scenarios were similar to those used in Study 1. Instructions for the dyadic and extradyadic nonsexual scenarios were similar, except that participants were asked to imagine themselves discussing recent concerns with either an opposite-sex colleague or their partner. In all

6 6 Personality and Social Psychology Bulletin 00(0) conditions, participants were instructed to describe in detail the specific scene, wishes, sensations, feelings, and thoughts that they and the other person experienced. After describing the scenario in narrative form, participants were asked to think about how they felt right then and to complete the sexual desire measure, described in Study 1 (α =.68). Participants also completed three items assessing their desire to engage in shared activities with their partner (e.g., I desire to engage in a personal conversation with my partner ; I desire to visit a museum with my partner ; α =.64). These items were intermixed with fillers assessing positive and negative feelings, described in Study 1. All items were rated on a 5-point Likert-type scale, ranging from 1 (not at all) to 5 (very much). Finally, participants provided demographic information and were then carefully debriefed. Results and Brief Discussion Manipulation check. Two judges independently indicated whether each written scenario involved one s partner or not and whether it was sexual or nonsexual. Neither of the judges had access to additional information about the participants while the scenarios were being read. In all written scenarios, there was a match between the instructed and actual target and content of the scenario. In addition, a two 2 (target of fantasy) 2 (content of fantasy) ANOVA on negative feelings for current partner did not yield any significant effect (see Table 2), ruling out the possibility that participants experienced more negativity in the control conditions than in the fantasy conditions. The effects of fantasies on desire and relationship-promoting behavior. To examine the effect of the target of fantasizing (partner vs. other) on the desire for sex and other relationship-promoting behaviors as well as the potential moderation effect of the content of fantasy (sexual vs. nonsexual), we conducted two 2 (target of fantasy) 2 (content of fantasy) ANOVAs. Table 2 presents the statistics relevant to these analyses. We found a significant main effect of the content of fantasy on the desire to engage in relationship-promoting behaviors, F(1, 98) = 6.04, p =.016, η 2 p =.058, indicating that the participants experienced greater desire to engage in these behaviors when they fantasized about sex (M = 3.75, SD = 0.80) than when they fantasized about nonsexual themes (M = 3.41, SD = 0.68). We also found that the target of fantasy moderated the effect of the content of fantasy on the desire to engage in relationship-promoting behaviors and marginally moderated the effect of the content of fantasy on sexual desire. Simple effect tests showed that in the nonsexual conditions, target of fantasy had no significant effect on the desire to have sex, F(1, 98) = 0.06, p =.940, η 2 p =.001, and the desire to engage in relationship-promoting behaviors, F(1, 98) = 0.68, p =.423, η 2 p =.007. However, in the sexual conditions, the target of fantasy had a significant effect on the desire to have sex, 2 F(1, 98) = 5.56, p <.020, η p =.054, and on the desire to engage in relationship-promoting behaviors, F(1, 98) = 7.33, 2 p <.008, η p =.070, such that participants experienced greater desire to engage in these behaviors in the dyadic sexual fantasy condition than in the extradyadic sexual fantasy condition. No other effects were significant. Study 2 replicated and extended the findings of Study 1 by indicating that extradyadic fantasizing did not hamper the desire to engage in sex and other relationship-promoting behaviors. Rather, dyadic fantasizing heightened these desires. The findings also demonstrated that the beneficial effects of dyadic fantasizing were unique to the sexual realm, such that sexually fantasizing about one s partner led to a greater desire for sexual and nonsexual relationship-promoting behaviors as compared with nonsexually fantasizing about one s partner. These findings, however, are confined to the laboratory context, which may compromise their ecological validity. Indeed, given that the fantasies were induced rather than spontaneous, the results might reflect the effect of the verbal processing involved in writing out a fantasy rather than visual mental imagery effects. In addition, because we did not assess whether participants relied on a commonly used fantasy while thinking about specific fantasmatic content or created a new fantasy, we could not examine whether the novelty inherent in such induced fantasies might moderate their effect on relationship outcomes. Finally, the proposed causal link between fantasizing and relationship outcomes should be viewed with caution, as we did not monitor future relational behaviors. Overall, it is not clear whether the results of Studies 1 and 2 would generalize to a more naturalistic and longitudinal design. These limitations were addressed in Study 3. Study 3 Studies 1 and 2 demonstrated the relational benefits that sexual fantasies about one s partner may have, even when experienced briefly in an artificial lab setting. Study 3 sought to replicate and extend these findings. For this purpose, Study 3 employed a daily experience methodology and determined whether these effects would apply in settings that are more natural. Furthermore, Study 3 assessed actual engagement in relationship-promoting behaviors rather than the desire to engage in such behaviors. Study 3 also explored more directly the potentially adverse relationship consequences of extradyadic fantasizing by including a measure of engaging in relationship-damaging behaviors. In particular, both members of 48 romantic couples independently described their sexual fantasies immediately after every occasion in which they experienced a sexual fantasy. In addition, they reported on the positive and negative behaviors that characterized their relationship on that day every evening for 21 days. We predicted that fantasizing about one s partner would be positively associated with relationship-promoting behaviors and negatively associated with relationship-damaging behaviors.

7 Birnbaum et al. 7 Table 2. Means, Standard Deviations, Statistics, and Effect Sizes of Desire for Engaging in Sex and Relationship-Promoting Behaviors for the Fantasy Conditions (Study 2; N = 102). Dyadic Extradyadic Sexual Nonsexual Sexual Nonsexual F(1, 98) η 2 η 2 95% CI for Desire 4.24 a (0.97) 3.56 b (0.92) 3.54 b (1.26) 3.58 b (1.14) [.00,.12] Promoting behaviors 4.04 a (0.67) 3.33 b (0.65) 3.50 b (0.84) 3.50 b (0.71) 6.04*.06 [.01,.16] Negative feelings 1.40 (0.87) 1.60 (0.91) 1.25 (0.64) 1.21 (0.51) [.00,.07] Note. Standard deviations are presented in parentheses. The F value refers to the interaction between the target and content of the fantasies. Different subscripts indicate groups that significantly differ from each other within each raw (p <.05). Items were rated on a 5-point Likert-type scale. CI = confidence interval. p <.10. *p <.05. Method Participants. Forty-eight heterosexual cohabiting Israeli couples 1 participated in this study in exchange for 350 NIS (about US$98). To determine sample size, we estimated the relative power for the planned multilevel-analysis using the PinT V2.1 computer program (Bosker, Snijders, & Guldemond, 2003). Although PinT was originally developed for power analyses of discrete predictors, Raudenbush and Xiao-Feng (2001) noted that approximations are possible in cases with continuous explanatory variables. Power for a random coefficient model was estimated for a sample of 48 couples and 21 time periods, with a moderate effect size (.30 in a correlation metric). Estimation of the standard errors assuming α =.05 yielded a power of.91. All participants were recruited via flyers or by word of mouth from universities, colleges, community centers, and sport clubs in the central area of Israel. Potential study participants were included in the sample if they (a) were in a steady monogamous relationship of longer than 6 months, (b) agreed to report on their daily relationship behaviors and sexual fantasies during the 21-day study period, and (c) were currently sexually active (defined as having had vaginal sex at least once a week in the 2 months preceding the study). Women ranged in age from 19 to 32 years (M = 24.92, SD = 4.18) and men ranged in age from 20 to 35 years (M = 26.87, SD = 2.90). Of the couples, 76% were cohabiting and 24% were married. None had children. Relationship length ranged from 9 to 60 months (M = 37.42, SD = 29.92). Number of reported sexual fantasies during the 21-day study period ranged from 6 to 21 (M = 13.31, SD = 4.92) among women and from 7 to 21 (M = 13.37, SD = 4.81) among men. Overall, the two members of the 48 couples had sexual fantasies on 32% of the days. In 68% of the days, one partner reported having experienced sexual fantasies, whereas the other did not. Measures and procedure. Couples who fulfilled the inclusion criteria were invited to the laboratory, filled out a background questionnaire, and were trained to complete the diary questionnaires. Participants were instructed to fill out forms independently and to refrain from discussing responses with their partner until completion of the study. Participants were asked to describe their fantasies in narrative form immediately after every occasion in which they experienced them. In addition, participants were instructed to report on the behaviors that characterized their relationship on that day every evening for 21 days. We contacted couples by telephone every 2 days to improve compliance with the diary protocol. At the end of the study, participants were debriefed and thanked for their participation. Daily sexual fantasies. Couples were given the same instructions used in Study 1, with the exception that they were not asked to limit the object of their fantasies. Participants were also asked to indicate whether each fantasy involved their relationship partner. Only fantasies that involved sexual themes were analyzed. On average, participants reported sexual fantasies in 13 of the 21 study days (59%), with men reporting sexual fantasies in 59% of the days and women reporting these fantasies in 60% of the days. On average, participants fantasized about their relationship partner in 66% of their reported fantasies, with men fantasizing about their female relationship partner in 55% of the cases and women fantasizing about their male relationship partner in 72% of the cases. This gender difference was significant, χ 2 (1) = 65.68, p <.001. Daily relationship-promoting and damaging behaviors. Participants reported whether or not they had enacted each of 19 specific behaviors toward their partner on a given day and, with a parallel item, whether their partner had enacted each of the same 19 behaviors toward them. The list included 10 relationship-promoting behaviors (e.g., I told my partner I loved him or her My partner told me he or she loved me ) and nine relationship-damaging behaviors (e.g., My partner criticized me I criticized my partner ). These behaviors were used in previous diary studies examining couple interactions (Birnbaum et al., 2011; Birnbaum et al., 2006). Participants indicated a behavior s occurrence by checking a box next to the item. In scoring participants answers to the daily questionnaire, we made the following computational steps. First, we counted the number of participants own and perceived partners

8 8 Personality and Social Psychology Bulletin 00(0) relationship-promoting behaviors reported on a given day (scores ranged from 0 to 14, M = 7.48 for women, M = 8.02 for men). The sample means of within-person variance for daily reports of relationship-promoting behaviors were 8.12 for women and 7.69 for men. Second, we counted the number of participants own and perceived partners relationshipdamaging behaviors reported on a given day (scores ranged from 0 to 8, M = 2.17 for women, M = 2.91 for men). The sample means of within-person variance for daily reports of relationship-damaging behaviors were 4.55 for women and 3.90 for men. Third, for each type of behavior (promoting, damaging), we collapsed participants reports of what they did in the relationship and what they reported having received from their partner into a single score because these two scores were highly correlated, r(46) =.71 for relationshippromoting behaviors, r(46) =.65 for relationship-damaging behaviors. The dyadic correlations between men s daily score and women s daily score across the study period were strong for both promoting and damaging behaviors, rs of.64 and.77, ps <.01. No significant difference between partners was found in these scores. Results and Brief Discussion A two-intercept, two-level hierarchical model for dyadic diary data was used to account for the nested structure of these data. The two-intercept approach simultaneously estimates unique intercepts and slopes for both male and female partners (Kenny, Kashy, & Cook, 2006). In the hierarchical model, Level 1 captures within-person variability across days, whereas Level 2 represents between-couple variability across partners (see Laurenceau & Bolger, 2005; Raudenbush, Brennan, & Barnett, 1995, for more details). This analytic approach allows the error terms in Level 1 to correlate across partners and thus better estimates the error structure of the repeated dyadic data than a three-level model does (i.e., days nested within persons nested within couples; Bolger & Laurenceau, 2013). In all analyses, we controlled for potential time-related artifacts by including a linear trend of the elapsed time in days. The time trend was centered on the middle of the time span (i.e., 11th day). Moreover, we controlled for the previous day s outcome variable to rule out daily serial dependency. This variable was first grand centered on its gender mean and then person mean-centered. Finally, the target of fantasizing was dummy-coded into two independent comparisons. The first comparison contrasted fantasizing about one s partner with fantasizing about someone else, whereas the second comparison contrasted fantasizing about one s partner with not fantasizing. As can be seen in Table 3, for both men and women, daily fantasizing about one s partner (as opposed to fantasizing about someone else) was significantly linked with more relationship-promoting behaviors. The same pattern emerged for the second dummy coded variable. For both sexes, daily fantasizing about one s partner (in contrast to not fantasizing) was associated with more relationship-promoting behaviors. However, daily fantasizing about one s partner (as opposed to fantasizing about another person or not fantasizing at all) was not linked with daily changes in relationship-damaging behaviors. Additional analyses indicated that fantasizing about someone who was not the current partner (as opposed to not fantasizing) was associated neither with changes in relationship-promoting behaviors (women: B = 0.31, SE =.33, t = 0.91, p =.384; men: B = 0.14, SE =.27, t = 0.52, p =.607) nor with changes in relationship-damaging behaviors (women: B = 0.03, SE =.21, t = 0.15, p =.879; men: B = 0.10, SE =.15, t = 0.66, p =.520). Study 3 replicated the findings of Study 2 in a more naturalistic context, showing that people were more likely to engage in relationship-promoting behaviors, such as complimenting their partners and acting considerately toward them, following sexually fantasizing about them. Sexually fantasizing about someone else, by comparison, was not significantly associated with engaging in either relationship-promoting or relationship-damaging behaviors. These findings suggest that sexual fantasies can improve romantic relationships by encouraging engagement in behaviors that are likely to increase affection between partners, as long as these fantasies involve one s current partner. Still, fantasizing about someone who is not the current partner is not necessarily harmful for the relationship, but it is not helpful either. Study 4 Study 4 sought to replicate the findings of Study 3 and extend them by exploring the processes that underlie the link between dyadic fantasizing and engaging in relationshippromoting behaviors. In particular, we examined whether the association between sexually fantasizing about one s partner and engaging in relationship-promoting behaviors would be mediated by relationship perceptions. To do so, we asked both members of 100 romantic couples to complete a nightly diary for 6 weeks in which they recorded the quality of their relationship, frequency of dyadic fantasies, desire to engage in sex with their partner, positive and negative relational perceptions, and relationship-promoting behaviors. Method Participants. One hundred heterosexual Israeli couples 2 participated in this study in exchange for 400 NIS (about US$105). Power was determined using the PinT V2.1 computer program (Bosker et al., 2003). Power for a random coefficient model was estimated for a sample of 100 couples and 42 time periods, with a moderate effect size (.30 in a correlation metric). Estimation of the standard errors assuming α =.05 yielded a power of.99. Recruitment and inclusion criteria were similar to those described in Study 3. Women ranged in age from 21 to 31 years (M = 23.93, SD = 1.84) and

9 Birnbaum et al. 9 Table 3. Hierarchical Linear Modeling Coefficients Predicting Fluctuations in Daily Relationship-Promoting and Damaging Behaviors From Daily Sexual Fantasizing (Study 3). Positive behaviors Negative behaviors B SE t p 95% CI B SE t p 95% CI W_intercept <.000 [6.314, 8.231] [1.070, 0.583] M_intercept <.000 [7.134, 9.042] [1.006, 0.514] W_fantasizing [0.154, 1.644] [0.232, 0.618] (partner vs. other) M_fantasizing [0.397, 1.571] [0.046, 0.665] (partner vs. other) W_fantasizing <.000 [0.623, 1.850] [0.028, 0.574] (partner vs. none) M_fantasizing [0.518, 1.749] [ 0.059, 0.720] (partner vs. none) W_time [ 0.029, 0.033] [0.014, 0.020] M_time [ 0.013, 0.049] [0.006, 0.028] W_previous day DV [ 0.035, 0.368] [0.125, 0.200] M_previous day DV [ 0.053, 0.336] [0.128, 0.193] Note. Previous day DV refers to yesterday s relationship-promoting behaviors in the equations predicting relationship-promoting behaviors and for yesterday s relationship-damaging behaviors in the equations predicting relationship-damaging behaviors. CI = confidence interval; W = women; M = men; DV = dependent variable. men ranged in age from 21 to 35 years (M = 25.60, SD = 2.70). Ninety-five percent of the couples were cohabiting and 5% were married. Two percent had children. Relationship length ranged from 1 to 98 months (M = 24.80, SD = 25.67). Measures and procedure. Couples who fulfilled the inclusion criteria were invited to the laboratory, filled out a background questionnaire, and were trained to complete the diary questionnaires. Participants were instructed to fill out the questionnaires independently and to refrain from discussing responses with their partner until completion of the study. s containing a link to the daily-level measures were sent independently to both partners each day for 42 days. We contacted couples by telephone every week to improve compliance with the diary protocol. In addition, we sent reminder s to participants who had not completed their daily diaries by midnight each night. At the end of the study, both partners were debriefed and thanked for their participation. Daily-level measures. On each diary day, participants completed measures of frequency of dyadic fantasies, positive and negative relational perceptions, relationship-promoting behaviors, sexual desire for their partner, and relationship quality. We used measures with a single item or a few items to minimize participant attrition (Bolger, Davis, & Rafaeli, 2003). All daily items were rated on a 5-point scale ranging from 1 (not at all) to 5 (very much), unless reported otherwise. To estimate scale reliability at the daily level, we created an additional item-level (nested within days and person) and ran a three-level unconditional model in hierarchical linear model(ing) (HLM) 7 software (Raudenbush, Bryk, Cheong, Congdon, & du Toit, 2011), as suggested by Nezlek (2012). HLM estimates the reliability of the item-level intercept, which is equivalent to Cronbach s alpha. Frequency of dyadic fantasies. Participants rated the extent to which they sexually fantasized about their partner during that day. Positive relational perceptions. Participants completed two items assessing the extent to which they perceived their relationship in positive terms on that day ( I felt committed to my relationship today ; I felt that I have a very valuable relationship today ; α =.61). Negative relational perceptions. Participants completed two items assessing the extent to which they perceived their relationship in negative terms on that day ( I felt frustrated in my relationship today ; I had doubts about the compatibility between me and my partner today ; α =.67). To support the distinction between positive and negative relationship perceptions, we conducted a confirmatory factor analysis. Fit indices of a two-factor model were adequate (χ 2 = , df = 3, p <.001, comparative fit index [CFI] =.95, root mean square error of approximation [RMSEA] =.13). Moreover, the two-factor model fitted the data better than a one-factor model, in which all the items loaded on a single factor (χ 2 = 1,158.43, df = 2, p <.001, CFI =.85, RMSEA =.265; model comparison: Δχ 2 = , Δdf = 1, p <.001). Relationship-promoting behaviors. Participants completed four items assessing the extent to which their partner behave positively toward them ( My partner behaved affectionately and warmly toward me today ; My partner behaved

10 10 Personality and Social Psychology Bulletin 00(0) thoughtfully toward me today ; α =.82). The outcome of interest was partners reports on relationship-promoting behaviors, indicating whether the participant had enacted these behaviors toward the partner. Sexual desire. Participants completed five items assessing their sexual desire for their partner during that day (e.g., I felt a great deal of sexual desire for my partner today ; I was very interested in having sex with my partner today ; α =.86). Relationship quality. Participants rated relationship quality with their partner on each day. Ratings were made on a 5-point scale, ranging from (1) poor to (5) excellent. Results and Brief Discussion To account for the nested structure of these data, we employed the same two-intercept, two-level hierarchical model for dyadic diary data described in Study 3. We used four sets of control variables in all the analyses. First, to control for potential time-related artifacts, we included a linear trend of the elapsed time in days. Second, to rule out auto-correlation (i.e., daily serial dependency), we controlled for the previous day s outcome variable. For example, in predicting today s relationship-promoting behaviors, yesterday s relationship-promoting behaviors were partialed out. Third, daily relationship quality was controlled for to better identify unique effects of fantasizing above the general affective tone of the relationship. Finally, as recommended by Bolger and Laurenceau (2013), to account for potential confounding between the within-person and the between-person levels of analysis, we controlled for between-person averages (e.g., the average relationshippromoting behaviors aggregated across all 42-diary days) for all primary variables. To ease coefficient interpretation, prior to analysis, all within-person predictors were first grand centered on their gender mean and then person mean-centered. The time trend was centered on the middle of the time span (i.e., 22nd day). For the within-person predictors, intercepts and slopes were allowed to vary across gender, but other effects were estimated as fixed effects. To assess mediation, we used a procedure recommended by Preacher, Zyphur, and Zhang (2010) for testing mediation in a multilevel data structure. First, we estimated the link between day-to-day fantasizing about one s partner (i.e., independent variable) and partner s relationship-promoting behaviors (i.e., the outcome of interest). Second, we tested the association between fantasizing and the mediators (i.e., positive and negative relationship perceptions). Third, we examined the link between the mediators and the outcome variable while controlling for the independent variable. The significance of the indirect effects of fantasizing on relationship-promoting behaviors through positive and negative relationship perceptions was estimated by the 95% confidence intervals of 5,000 bias-corrected and accelerated bootstrapping analyses (MacKinnon, Lockwood, & Williams, 2004). A significant statistical effect at α <.05 is indicated when the value zero is not included in the confidence interval. Results of the multilevel dyadic analyses are presented in Table 4. Section I in Table 4 presents the association between the respondent s fantasizing and partner s relationship-promoting behaviors. The results indicated that for both sexes, daily fantasizing about one s romantic partner was positively linked with partner s reports on relationship-promoting behaviors. This link was found to be statistically significant above the effects of time, daily relationship quality, yesterday s relationship-promoting behaviors, and average fantasizing. The second and third sections of Table 4 present the associations between fantasizing and relationship perceptions. Results indicated that for both male and female partners, daily fantasizing was positively linked with positive relationship perceptions and negatively linked with negative relationship perceptions. In the fourth section of Table 4, we examined the associations between the mediators and the outcome of interest. Results showed that for both romantic partners, positive relationship perceptions were positively linked with partners relationship-promoting behaviors, whereas negative relationship perceptions were reversely associated with partners relationship-promoting behaviors. To test whether relationship perceptions mediated the associations between fantasizing and partners relationship-promoting behaviors, we calculated the 95% confidence interval (CI) of these indirect effects, using 5,000 bias-corrected and accelerated bootstrapped samples. Results showed that the 95% CI of the indirect effects for fantasizing as a predictor of relationship-promoting behaviors through positive relationship perceptions (women s 95% CI = [0.01, 0.03]; men s 95% CI = [0.01, 0.04]) and negative relationship perceptions (women s 95% CI = [0.01, 0.02]; men s 95% CI = [0.01, 0.02]) did not include zero. These findings indicated that the associations between fantasizing and partner s promoting behaviors were significantly mediated by relationship perceptions. Further analysis examined the extent to which the primary associations, as presented in Figure 1, differed across gender. The results indicated that gender did not moderate the associations between fantasizing and positive (B = 0.013, SE =.009, t = 1.41, p =.162) and negative (B = 0.026, SE =.015, t = 1.73, p =.087) relationship perceptions. Moreover, we neither found gender differences in the link between positive relationship perceptions and relationship-promoting behaviors (B = 0.013, SE =.022, t = 1.35, p =.178) nor between negative perceptions and relationshippromoting behaviors (B = 0.001, SE =.021, t = 0.03, p =.978). Finally, gender did not moderate the direct path between fantasizing and relationship-promoting behaviors (B = , SE =.017, t = 1.60, p =.109). 3 Finally, we tested whether daily fantasizing about one s partner predicted sexual desire. Results of the two-intercept,