Slovenian Validation of the Capacity to Love Inventory – A Preliminary Study

Slovenia


Introduction
Intimate relationships are evolutionarily important for our survival and reproduction, and thus a fundamental human need (Baumeister & Leary, 1995).For many people, the most important interpersonal bond is the spousal relationship.While interpersonal relationships can be a source of happiness and fulfilment on the one hand, relationship conflict is likely to negatively impact subjective and physiological aspects of a person's functioning as well as their overall well-being (Cramer, 2002;Kiecolt-Glaser et al., 2005).There is a growing body of evidence showing that marital discord increases the risk for physical health problems.Studies from the 1980s and 1990s have consistently shown that the quality of romantic relationships is associated with health outcomes (Burman & Margolin, 1992;Kiecolt-Glaser & Newton, 2001).Some studies have even shown that the quality social relationship contributes to a 50% higher likelihood of survival (Holt-Lunstad et al., 2010).
Social support is a well examined psychological factor influencing health outcomes (Uchino, 2009).For example, marriage has been shown to affect spousal health behaviours consistently over time (Homish & Leonard, 2008;Meyler et al., 2007).Recently, low marital satisfaction was found to be related to health outcomes such as increased levels of inflammation in a large sample (Whisman & Sbarra, 2012).Further, couples who engage in more hostile behaviours during marital discussions have generally elevated blood pressure and heart rate compared to less hostile couples (reviewed in Robles & Kiecolt-Glaser, 2003).Finally, healthy romantic relationships appear to have benefits ranging from lower stress reactivity to better physical health (Coan et al., 2013;Kiecolt-Glaser & Newton, 2001).
Similarly, relationship quality is related to mental health.Marital maladaptivness and relationship discord is associated with perceived stress, which might contribute to mental health problems (Funk & Rogge, 2007;Whisman & Baucom, 2012), however, the direction of the association can also be opposite (Benazon & Coyne, 2000).Studies have shown that individuals who report greater relationship discord are at increased risk for mental health problems, and this association has been demonstrated for many psychological disorders (Whisman, 2013).Because of the detrimental effects it can have on an individual's health, relationship distress can be considered a public health issue (Foran et al., 2015).

The Importance of Love and Capacity to Love
Love is a fundamental human phenomenon (Fletcher et al., 2015), however, love research has not settled on a common theory of love, leading to many unanswered questions (Levin, 2000).Some empirical approaches to love have focused on specific aspects such as the characteristics of romantic love (Rubin, 1970) or definitions of love styles commonly referred to as eros, agape, pragma, or others (Lee, 1976;Hendrick & Hendrick, 1986).One of the first unified theories of love was proposed by Sternberg and Barnes (1988), who pointed to intimacy, passion and commitment as love-components that can be coalesced into different phenotypes of love relations.However, empirically established conceptions of love taking etiological dimensions into account are still to be established.The concept of capacity to love examined in this study is based on an integrated developmental object relations theory (Bergmann, 1971;Gottlieb, 2002;Kapusta et al., 2018;Kernberg 1974Kernberg , 1977Kernberg , 2011aKernberg , 2011b;;Modell, 1963).It consists of multiple components and refers to the ability to enter into and maintain lasting romantic love relationships (Kernberg, 2011a).Capacity to love integrates several dimensions (used interchangeably with the terms subscales and factors throughout the text) closely related to personality characteristics, which is based on the observation, that individuals with personality disorders struggle both in forming and sustaining close relationships (Whisman et al., 2007;Zimmerman & Coryell, 1989) and if related, they commonly experience conflict, violence and instability in relationships (South, 2014).The mechanisms involved in poor romantic relationship functioning are not yet fully understood (Boutwell et al., 2012;Krueger et al., 1998;Lavner et al., 2015).

The Purpose of the Study
Our primary objective was to establish psychometric properties of the Capacity to Love Inventory (CTL-I) (Kapusta et al., 2018) in a Slovenian sample, thereby adding to the growing set of validation studies, the CTL-I currently being validated on Austrian, Polish and Italian samples (Kapusta et al., 2018;Margherita et al., 2018).Our secondary goal was to examine the association between the capacity to love and quality of relationship functioning assessed by the Quality of Relationship Inventory (Pierce et al., 1991) in terms of external validity.

Procedure and Participants
An online invitation to participate in the study was sent to psychology and natural science students at two public universities in Slovenia with the approval of faculty departments.Faculty departments sent out invitation links to participate in the study to all enrolled students with an active university e-mail address.Participants could also forward the invitation to their social network.
In order to participate in the study, participants had to agree to the Privacy policy, which included information about the aim of the study, participants' rights regarding anonymity, data storage, and use of the data collected.Participants were guaranteed anonymity throughout the processthere was no data collected that would allow the identification of the participants.The research data was used exclusively for the dissemination procedures.The procedure followed the ethical and research standards of the University of Primorska and the Helsinki declaration.
The selection of psychology and natural science students balanced the target population proportionally to gender differences: psychology is dominated by females, while natural sciences by males.However, more women (79.5%) participated in the study.A similar overproportion of females emerged in previous validation studies on this topic (Kapusta et al., 2018;Margherita et al., 2018).
The online survey consisted of the Capacity to Love Inventory (Kapusta et al., 2018) and the Quality of Relationship Inventory (Pierce et al., 1997) as well as demographic variables (presented in Table 1).The Capacity to Love Inventory was translated from English to Slovenian for the purpose of the study, using the backtranslation procedure (Van de Vijver & Leung, 1997).
A total of 601 individuals opened the online invitation letter, and 37% of the questionnaires were completed entirely.Our final sample consisted of 224 participants.The average age of participants was 24.5 years (SD = 6.07, range 18 -50).Demographic data is presented in Table 1.
Descriptive statistical analyses were performed with the Statistical Package for the Social Sciences (SPSS) 19.0.Confirmatory factor analysis of the CTL-I was conducted in R 4.1.1.(R Core Team, 2019), using lavaan package (Rosseel, 2012).

Measures
The Capacity to Love Inventory (CTL-I; Kapusta et al., 2018), is a 41 item selfreport questionnaire rated on a 4-point scale (1disagree to 4agree).The questionnaire consists of six dimensions: Interest in the life project of the other (INT; "I feel enriched to see the personal growth and life experience of my partner."),basic trust (BRT; "I am comfortable with my partner and I usually feel safe in his/her company"), gratitude (GRT; "I feel gratitude for the existence of my partner"), common ego ideal (CEI; "We always try to work on our relationship"), permanence of sexual passion (PSP; "Sexual boredom arises in long-term relationships", reversed) and loss and mourning (LOM; "I am often unwilling to accept the end of my relationships", reversed).The scale has been translated through the back translation process (Van de Vijver & Leung, 1997) into Slovenian.
In the original version, Cronbach's alpha of the total scale is .90,for the subscales values are .73for Interest in the other, .86 for Basic trust, .81 for Gratitude and Humility, .81 for Common Ego Ideal, .83 for Permanence of sexual passion, and .75 for Loss and mourning.A second validation on an Italian sample showed Cronbach's alpha values in a similar range (Kapusta et al., 2018).
The Quality of Relationships Inventory (QRI; Pierce et al., 1997), is used to assess relationship-specific perceptions of social support (Support subscale), consisting of individual's expectations about the availability of support from particular significant others (Pierce et al., 1991(Pierce et al., , 1997)).The QRI focuses on perceived support within an intimate relationship, rather than reflecting a person's perceived support from any individual in his or her social network.The QRI includes an assessment of two other features highly relevant to relationship quality: Conflict (the extent to which the relationship is a source of conflict, anger and ambivalent feelings) and Depth (the importance of the relationship).The QRI has proven useful in both clinical and nonclinical relationship research.For example, research has demonstrated that an individual's relationship-specific perceptions, as assessed by the QRI, are useful in predicting that person's adjustment (e.g., loneliness, selfesteem, anxiety, depression, coping; Pierce et al., 1997;Ptacek et al., 1999).QRI is based on the assumption that general predispositions to engage in and respond to social behaviour are grounded in expectations, derived from Bowlby's (1980) theory of working models and relations between the self and important others.
In our study, we used the Slovene version of the QRI (Zager Kocjan & Avsec, 2014), consisting of 25 self-report items evaluated on a 4-point scale ranging from 1 (not true) to 4 (almost always true).The scale has three dimensions with sufficient internal consistency measured by Cronbach alpha: the Support subscale (.86) measures the level of mutual support in the relationship, the Depth subscale (.82) measures the dependency and depth of the interpersonal relationship and the Conflict subscale (.90) measures critical and conflict-related issues.The Support and Depth dimensions reflect better relationship quality, while higher scores in the Conflict subscale are interpreted as lower relationship quality.

Results
We tested the theory-driven model developed by Kapusta et al. (2018) with a CFA analysis: a six-factor model with 41 items and scales being allowed to correlate with each other.Table 2 shows the descriptive statistics of our sample.The results of the Kolmogorov-Smirnov test of scales and subscales indicated that most of the scales and subscales did not have a normal distribution.Confirmatory factor analysis was conducted using a maximum likelihood estimation with robust standard errors and a Satorra-Bentler scaled test statistic.Model fit was assessed using the following fit indexes: (1) the chi-squared statistic and its degree of freedom; (2) the Standardized Root Mean Square Residuals (SRMR); and, (3) the Root Mean Square Error of Approximation (RMSEA) and its 90% confidence interval (90% CI).In line with what Schermelleh-Engel and colleagues ( 2003) affirmed, the model fits the data when ꭓ 2 /df equal or < 2, RMSEA equal or < .05(90% CI: the lower boundary of the CI should contain zero for exact fit and be < .05for close fit), although Browne and Cudeck (1993) argued that values ranging from .05 to .08 are indicative of good model adequacy.Internal consistencies for the scales of the best fitting model were computed using Cronbach's coefficient alpha for each factor.
Based on the results of the chi-squared test, a lack of overall fit for the model tested (p < .01)was shown; which may be due to the sensitivity of this statistic to large sample sizes (Hu & Bentler, 1999;Kahn, 2006).In fact, chi-square is highly sensitive to sample size: as the size of the sample increases, absolute differences become a smaller and smaller proportion of the expected value.Moreover, a lack of this fit index is common in social sciences due to the interconnectedness of psychological concepts (Schermelleh-Engel et al., 2003;Vandenberg, 2006).
An RMSEA value of less than .06suggests an excellent data fit, while an RMSEA value of less than .08suggests an acceptable fit (Schreiber et al., 2006).The goodness-of-fit indices (RMSEA and SRMR) show acceptable scores for the RMSEA (.06) with less than .08being acceptable (Steiger, 2007) as well as satisfactory scores for the SRMR at .07 with an acceptable score cut-off being less than .08(Hu & Bentler, 1999).Results show a comparable fit to the results obtained in the original version of the CTL-I (Kapusta et al., 2018) CTL-I: chi 2 /degrees of freedom = 3.13 (2391.9/764),SRMR = .060,RMSEA = .062(90% CI .060-.065) as well as the Italian version where fit indices were: chi 2 /degrees of freedom = 3.40 (2598.87/764),SRMR = .05,RMSEA = .06(90% CI .055-.060) (Margherita et al., 2018).Table 4 shows the results of the confirmatory factor analysis.As the QRI was used as a measure of convergent validity for the CTL-I dimensions, we expected significant correlations on the majority of the dimensions.In line with these expectations, most QRI subscales and the CTL-I subscales correlated significantly (Table 5).As expected, the Conflict subscale of the QRI correlated negatively with all the CTL-I subscales, while the highest (negative) correlation was with Basic trust.The QRI subscales of Social support and Depth showed significant correlations with the CTL subscales Interest, Basic trust, Gratitude, and Common go ideal with correlations ranging from .39 to .71.These were moderate to high correlations significant at p < .05.The subscales of Permanence of sexual passion showed only a slight correlation with QRI depth, while Loss and mourning showed no correlations with any of the subscales.Overall, results indicate a significant, moderate to strong correlation between quality of relationship and capacity to love (r = .66,p < .01)and its subscales (social support r = .62,p < .01;depth r = .62,p < .01;conflict r = -.37,p < .01).
CTL-I subscales Basic trust, Gratitude and Common ego ideal significantly correlated between each other (Table 6).The Permanence of sexual passion and Loss and mourning subscale did not show significant correlations with the other 4 subscales.CTL-I total showed significant correlations with all six subscales.

Discussion
The purpose of our study was to continue the validation process of the Capacity to Love Inventory (CTL-I), a quantitative measure for assessing an individual's capacity to love, on a Slovene sample.
The Cronbach's alphas for the subscales were lower for the subscales interest, loss and mourning and permanence of sexual passion, while basic trust, gratitude and common ego ideal showed good internal consistency.Model fit was tested using CFA showing satisfactory results (RMSEA and SRMR) in confirming the factor structure of the Slovenian version of the CTL-I.However, the chi-squared test analysis showed a lack of overall model fit, as was also the case in the previous validation studies (Kapusta et al., 2018;Margherita et al., 2018).As the chi-squared test is sensitive to sample size (Hu & Bentler, 1999;Kahn, 2006) this result is common in psychological constructs exhibiting high intercorrelations.Overall, our results are comparable to the results of the two previous validation studies (Kapusta et al, 2018;Margherita et al., 2018).
Due to the importance of love in forming and maintaining intimate bonds, we hypothesized a positive association between the CTL-I and relationship quality.Strong and significant correlations were found between the QRI subscale of Social support and the CTL-I subscales Interest, Basic trust, Gratitude, and Common ego ideal.The same was found for the QRI Depth subscale.The QRI Conflict subscale also showed significant negative correlations with the four CTL-I subscales mentioned above.The Permanence of sexual passion and Loss and mourning subscales, however, showed little to no correlation with the QRI subscales.A result, which is in line with Kapusta and colleagues' (2018) weak associations between these scales.Given the fact of smaller sample size in our study, replication in larger Slovenian samples is needed.
Also, the correlational analysis between CTL-I subscales and the total score showed slightly lower values than those found previously (Kapusta et al., 2018;Margherita et al., 2018).Correlations between Interest in the other, Basic Trust, Gratitude, Common ego ideal and the Total CTL-I score were moderately to high as well as statistically significant.Additionally, unlike the aforementioned studies, we found no significant correlation between Permanence of sexual passion and Loss and mourning with the other subscales.Loss and mourning as measured by the CTL-I refers to an individual's reactions to and the level to which they are affected by inevitable relationship ruptures.In both previous studies, correlations between these two subscales were significantly lower compared to the other subscales, with Loss and mourning having very modest to no correlation with any of the factors.The PSP and LOM subscales should be reviewed in further studies especially using the Slovenian translation of the CTL-I.In Kapusta and colleagues (2018) and Margherita and colleagues (2018) correlations, while being statistically significant, were the lowest between PSP and LOM among the six subscales.We would therefore suggest further studies to be conducted to re-examine the validity of the two subscales and improve on the Slovenian CTL-I.
The Capacity to Love Inventory was developed in an attempt to gain deeper insight into the dimensions of the psychotherapeutic process and its outcomes and could thus be an important tool for monitoring the effectiveness of clinical intervention (Margherita et al., 2018).Authors have also theorized the potential of the instrument in promoting protective factors in the general population (Margherita et al., 2017;Tessitore & Margherita, 2017).The CTL-I could prove valuable in further exploring the mechanisms of relationship functioning in nonclinical and subclinical populations, as these mechanisms of relationship quality have not yet been fully understood (Boutwell et al., 2012;Lavner et al., 2015).
Perhaps the largest advantage of the CTL-I as compared to other relationship measures is that it can be used as a measure of psychodynamically conceptualized difficulties in relationship functioning thus valuable in clinical settings as a diagnostic tool for problems in intimate relationships.For example, psychoanalytic theories suggest an association of depression with the loss of loved objects (Desmet, 2013).Accordingly, a mature capacity to love is associated with the ability to bear depressive feelings (Klein, 1940(Klein, , 1946)).In line with psychoanalytic theories, the original validation study showed significant negative correlations between depression and all the capacity to love dimensions (Kapusta et al., 2018) pointing to further validity of the construct.

Implications
As intimate relationship functioning is associated with aspects of both mental and physical health, it is important to find ways to assess and improve the quality of relationships.The primary evolutionary goal of intimate relationships is essentially the bearing of offspring.Thus, parent relationship quality is of vital importance for a child's psychological development (Schore, 2013).Parental discord has been shown to be associated with child psychological outcomes (Davies et al., 2018;Knopp et al., 2017;Tan et al., 2020).In line with developmental cascades (Masten & Chichetti, 2010) parent relationship quality can have far-reaching consequences on a child's mental health consequentially influencing the child's romantic interactions and relationship quality (Handley et al., 2019).Improving relationship functioning could thus have far-reaching societal benefits and measures such as the CTL-I can aid in the process of identifying and treating specific psychological sources of intimate relationship distress.

Limitations
Traditional power estimations for Structural Equation Modeling (SEM) (e.g., Bentler & Chou, 1987;Tanaka, 1987) might suggest that the sample size of the current study is too small to reach adequate power.However, more recent power estimations for SEM suggest sample sizes of 200 and above, as in our study to be adequate (Boomsma & Hoogland, 2001;Hoogland & Boomsma 1998;Kim et al., 2005;Kline, 2005).A second aspect, the disproportionate number of women participating in the study compared to men needs also to be considered.In line with previous CTL-I studies, gender bias can be explained by findings that women might be interested in relationships and participating in research more than men (Fraley et al., 2011;Su et al., 2009).To be argued similarly, our sample was composed of young participants (M = 24.5).Given the fact that age is related to relationship experience, this might have also an effect on the overall result.For example, some recent research has shown a decline in sexual experience among young adults (Herbenick et al., 2021).However, the mean age and age range of our sample was very similar to the age of the two previous samples (16 to 66, M = 28.92, Austrian [Kapusta et al., 2018] and 18 to 50, M = 23.24,Polish [Kapusta et al., 2018]) of the original validation study (Kapusta et al., 2018).An additional potential limitation in the generalizability of our findings was the inclusion of both humanistic and natural science students in our study.Some research has shown personality factors to be associated with vocational choice (Balsamo et al., 2012;Coenen et al., 2021).These personality traits could in turn be associated with relationship quality and experience (Vater & Schröder-Abé, 2015).

Conclusion
The main objective of the present study was primarily to validate the Slovenian version of the Capacity to Love Inventory.We were largely able to confirm the factor structure of the CTL-I.The results of the confirmatory factor analysis were analogous to those of the previous two validation studies.A second goal of the study was to assess its association with the QRI, which was in turn also a measure of the CTL-I's convergent validity.The dimensions Loss and mourning and Permanence of sexual passion, showed lower than expected associations with the QRI dimensions as well as CTL-I subscales, which warrants further examination.We believe the CTL-I is an important measure for assessing both clinical as well as non-clinical relationship functioning.Overall, we believe our study should be seen as a preliminary attempt at the validation of the Slovenian version of the CTL-I as well as a valuable supplement to the process of validating the concept of the capacity to love internationally.

Table 1
Characteristics of the Sample

Table 2
Descriptive Statistics for the Studied Measures and Comparison of Means

Table 3
Fit Indices for Our and Previous Studies

Table 4
Results of the Confirmatory Factor Analysis -Item Loadings of the Slovenian CTL-I * Reverse-coded item.INT = Interest; BTR = Basic Trust; GRT = Gratitude, CEI = Common Ego Ideal; PSP = Permanance of Sexual Passion; LOM = Loss and Mourning.