TYPE Original Research PUBLISHED 06 July 2023 DOI 10.3389/fpsyg.2023.1212036 The Toronto Mindfulness Scale OPEN ACCESS and the State Mindfulness Scale: psychometric properties of the EDITED BY Francisco Sampaio, Escola Superior de Enfermagem do Porto, Portugal REVIEWED BY Spanish versions César González-Blanch, Marqués de Valdecilla University Hospital, Spain Eunjin Kim, Jaime Navarrete 1,2,3†, Marta Fontana-McNally 1,2†, Wonkwang University, Republic of Korea Ariadna Colomer-Carbonell 1,2,3, Juan P. Sanabria-Mazo 1,2,3, *CORRESPONDENCE Daniel Pinazo 4, Antonio-José Silvestre-López 5, Mark Lau 6, Albert Feliu-Soler albert.feliu@uab.cat Galia Tanay 7, Javier García-Campayo 8,9, Marcelo Demarzo 10, These authors share first authorship † Joaquim Soler 11,12, Ausiàs Cebolla 13,14, Albert Feliu-Soler 15* and RECEIVED 25April 2023 Juan V. Luciano 1,2,3,15 ACCEPTED 14 June 2023 PUBLISHED 06 July 2023 1 Institut De Recerca Sant Joan De Déu, Esplugues De Llobregat, Spain, 2 Teaching, Research & Innovation Unit, Parc Sanitari Sant Joan De Déu, Sant Boi De Llobregat, Spain, 3 CIBER of Epidemiology CITATION and Public Health (CIBERESP), Madrid, Spain, 4 Department of Evolutionary, Educational and Social Navarrete J, Fontana-McNally M, Psychology and Methodology, Universitat Jaume I, Castellón de la Plana, Spain, 5 Department of English Colomer-Carbonell A, Sanabria-Mazo JP, Studies, Universitat Jaume I, Castellón de la Plana, Spain, 6 Department of Psychiatry, Faculty of Pinazo D, Silvestre-López A-J, Lau M, Tanay G, Medicine, University of British Columbia, Vancouver, BC, Canada, 7 Observing Minds Lab, School of García-Campayo J, Demarzo M, Soler J, Psychological Sciences, University of Haifa, Haifa, Israel, 8 Institute of Health Research of Aragon (IIS Cebolla A, Feliu-Soler A and Luciano JV (2023) Aragón), Miguel Servet University Hospital, Zaragoza, Spain, 9 Universidad de Zaragoza, Zaragoza, Spain, The Toronto Mindfulness Scale and the State 10 Mente Aberta - the Brazilian Center for Mindfulness and Health Promotion- Universidade Federal de Mindfulness Scale: psychometric properties of São Paulo- UNIFESP, São Paulo, Brazil, 11 Department of Psychiatry, Hospital de la Santa Creu i Sant Pau, the Spanish versions. Barcelona, Spain, 12 CIBER of Mental Health (CIBERSAM), Madrid, Spain, 13 Department of Personality, Front. Psychol. 14:1212036. Evaluation and Psychological Treatments, University of Valencia, Valencia, Spain, 14 CIBER of Obesity and doi: 10.3389/fpsyg.2023.1212036 Nutrition (CIBEROBN), Madrid, Spain, 15 Department of Clinical & Health Psychology, Autonomous COPYRIGHT University of Barcelona, Bellaterra, Spain © 2023 Navarrete, Fontana-McNally, Colomer- Carbonell, Sanabria-Mazo, Pinazo, Silvestre- López, Lau, Tanay, García-Campayo, Demarzo, Soler, Cebolla, Feliu-Soler and Luciano. This is an open-access article distributed under the Objectives: The Toronto Mindfulness Scale (TMS) and the State Mindfulness Scale terms of the Creative Commons Attribution (SMS) are two relevant self-report measures of state mindfulness. The purpose License (CC BY). The use, distribution or of this study was to examine the internal structure and to offer evidence of the reproduction in other forums is permitted, provided the original author(s) and the reliability and validity of the Spanish versions of the TMS and SMS. copyright owner(s) are credited and that the Methods: Data from six distinct non-clinical samples in Spain were obtained. They original publication in this journal is cited, in accordance with accepted academic practice. responded to the TMS (n=119), SMS (n=223), and measures of trait mindfulness, No use, distribution or reproduction is decentering, non-attachment, depression, anxiety, stress, positive and negative permitted which does not comply with these affect, self-criticism, and self-reassurance. The internal structure of the TMS and terms. SMS was analyzed through confirmatory factor analysis. Reliability, construct validity, and sensitivity to change analyses were performed. Results: The correlated two-factor structure (curiosity and decentering) was the best-fitting model for the TMS (CFI=0.932; TLI=0.913; RMSEA=0.100 [0.077– 0.123]; WRMR=0.908). The bifactor structure (general factor, mindfulness of body, and mindfulness of mind) was the best-fitting model for the SMS (CFI=0.961; TLI=0.950; RMSEA=0.096 [0.086–0.106]; WRMR=0.993). Adequate reliability was found for both measures. The reliability of the SMS specific factors was very poor when controlling for the general factor. The patterns of correlations were mainly as expected and according to previous literature. The TMS and SMS have been able to detect state mindfulness changes after different meditation practices. Conclusion: Validity evidence is provided to support the use of the TMS and SMS in Spanish populations, though the reliability of the SMS specific factors merit revision. Frontiers in Psychology 01 frontiersin.org Navarrete et al. 10.3389/fpsyg.2023.1212036 KEYWORDS toronto mindfulness scale, state mindfulness scale, spanish validation, confirmatory factor analysis, WLSMV, omega-hierarchical 1. Introduction addition, Ireland et al. (2019) replicated and expanded Lau et al. (2006) findings regarding the original –English- version of the Mindfulness is generally defined as a non-elaborative, TMS. Regarding dimensionality, Ireland et al. (2019) and Yu et al. non-judgmental, present-centered awareness where different (2021) found support for the two-factor structure after implementing thoughts, feelings, and sensations that arise in one’s attentional field some modifications that mainly involved the curiosity factor. Overall, are acknowledged and accepted as they are (Kabat-Zinn, 1990). It has the TMS showed a good internal consistency and adequate been described as a trait-like kind of awareness, though mindfulness convergent/discriminant validity, correlating positively with trait can also be viewed as a mode, or state-like quality, that is maintained mindfulness (only decentering factor), decentering, frequency of only when attention to experience is intentionally set with an open, meditation practice, wellbeing, self-awareness, inner peace, positive non-judgmental orientation to experience (Bishop et al., 2004). In affect, and negatively with stress, depression, and anxiety with a small- fact, the rationale of mindfulness-based interventions (MBI) is that to-medium strength for all the associations (r range from 0.02 to 0.54; evoking the state of mindfulness regularly across meditation practice Lee et al., 2010; Ireland et al., 2019; Yu et al., 2021). increases the propensity of an individual toward mindfulness in The SMS is a 21-item scale that assesses two state mindfulness everyday life (Davidson, 2010). In this regard, Kiken et al. (2015) aspects: one reflecting state mindfulness of bodily sensations and the showed that repeated mindfulness meditation practice within an MBI other reflecting state mindfulness of mind. Dimensionality analyses increased individuals’ state mindfulness over time, which in turn, from the original validation study showed that the SMS entailed a predicted changes in trait mindfulness and psychological distress. hierarchical two-factor structure including a higher-order state As repeated measures of key state variables during MBIs mindfulness factor (Tanay and Bernstein, 2013). As the original contribute to a better understanding of the trajectory of mindfulness authors noted (Ruimi et al., 2022), this scale has been translated in to training (Navarrete et al., 2022), the need for researchers and clinicians various languages, including Spanish, and has been used in many to have access to reliable measures is growing. Nevertheless, when research settings (e.g., Navarrete et al., 2021a). However, except for the attempting to measure mindfulness, the difficulty arises depending on original work by Tanay and Bernstein (2013), only one study has whether trait or state mindfulness is the target. Most self-report assessed its psychometric properties in another culture (Andrade measures of mindfulness assess the construct as a trait-like behavior et al., 2019). In a Portuguese convenience sample, Andrade et al. (i.e., a general tendency to be mindful in daily life) as opposed to a (2019) showed that the original hierarchical two-factor structure plus state-like construct (Siegling and Petrides, 2014; Baer, 2019). An four pairs of correlated error terms were not supported. In addition, example of the most popular trait mindfulness measure is the Five- they tested a modified hierarchical two-factor structure with six pairs Facet Mindfulness Questionnaire (FFMQ; Baer et al., 2006), which is of correlated error terms, for which they found an adequate goodness used worldwide (Lecuona et al., 2020). In contrast, there are very few of fit. In both Tanay and Bernstein (2013) and Andrade et al. (2019) self-report measures focused on state mindfulness, which studies, internal consistency was adequate and convergent/ consequently means that their psychometric properties have been less discriminant validity analyses were in the expected direction, showing studied (Baer, 2019). that state mindfulness was positively correlated with curiosity, Currently, the two most important self-report measures of state decentering, some facets of trait mindfulness, and positive affect, and mindfulness are (Baer, 2019): the Toronto Mindfulness Scale (TMS; negatively with suppression emotion regulation strategy with a small- Lau et al., 2006) and the State Mindfulness Scale (SMS; Tanay and to-medium strength for all the associations (r range from 0.05 to 0.56; Bernstein, 2013). The TMS is a reliable and valid measure of state Tanay and Bernstein, 2013; Andrade et al., 2019). mindfulness, derived from Bishop et al.’s (2004) operational definition As mindfulness research grows among Spanish-speaking of mindfulness which comprised the components of ‘Orientation to countries, the need for reliable and valid Spanish adaptations of these Experience’ -characterized by openness and curiosity- and ‘Self- scales arises (Hervás et al., 2016). Moreover, further psychometric Regulation of Attention’ – being aware of current thoughts, feelings, studies of the TMS and SMS are warranted in order to clarify some and sensations without getting caught up in ruminative or elaborative aspects about their factor structure (Ireland et al., 2019; Ruimi et al., thinking-. In contrast, the original SMS framework was based on an 2022). Finally, previous studies used maximum likelihood or integration of the traditional Buddhist concept of mindfulness and maximum likelihood robust estimation methods when confirmatory also Bishop et al.’s (2004) construct definition. factor analyses were conducted, which are less optimal methods for The TMS is a 13-item scale that encompasses two separate factors: Likert-type data than diagonally weighted least squares (Li, 2016). curiosity and decentering. Curiosity refers to the quality with which Against this background, the present work assesses the one becomes aware in the present moment, while decentering refers psychometric properties of the Spanish versions of the TMS and the to the ability to be aware of one’s experience without being drawn in SMS in pooled samples from the Spanish general population. More by the different stimuli (Lau et al., 2006). The TMS has been adapted specifically, the objectives of this study were to analyze the factor and validated to Korean (Lee et al., 2010) and Chinese (Yu et al., 2021) structure of both scales (i.e., the TMS and the SMS), their reliability, populations, though only the last performed factor analysis. In convergent/discriminant validity, and sensitivity to change. Regarding Frontiers in Psychology 02 frontiersin.org Navarrete et al. 10.3389/fpsyg.2023.1212036 the first objective, we expected that a correlated two-factor model and sample of students and administration and services staff from the a hierarchical two-factor model for the TMS and the SMS, respectively, University of Jaume I (Castellón, Spain). would yield the best fit in our dataset (Hypothesis 1). Moreover, we expected adequate internal reliability (Hypothesis 2) and convergent/discriminant validity for these measures. In this sense, 2.2. Procedure we hypothesized that the TMS scores would be positively associated with mindfulness facets, decentering, and non-attachment, as well as Initially, permission from the original authors was obtained for negatively associated with depression, anxiety, and stress with a small- translating and validating the TMS and SMS. A team of Spanish to-medium strength for all the associations (Hypothesis 3). Similarly, psychologists, who were proficient in English and experts in we hypothesized that SMS scores would be positively associated with mindfulness interventions and contemplative psychology, translated TMS scores (strong association expected), trait mindfulness facets the original version of the TMS and SMS into Spanish. Then, (i.e., observing, describe, non-judging, and non-reactivity), positive discrepancies were discussed and the items were back-translated into affect, and self-reassurance, as well as negatively associated with self- English by a native English speaker also fluent in Spanish and criticism with a small-to-medium strength for all the associations independent from the team. Again, discrepancies with the original (Hypothesis 4). Finally, it was anticipated that both state mindfulness TMS and SMS were discussed and the Spanish versions were adapted measures would be sensitive to change after meditation practice, until they were equivalent to the English versions. The final versions showing statistically significant higher TMS and SMS scores in of the Spanish TMS and SMS can be found in the supplemental participants after common meditation practices (Hypothesis 5). materials section (Supplementary Appendix A). This psychometric study was approved by the Ethics Committee at the Sant Joan de Déu Foundation (PIC-141-19). Participants from 2. Materials and methods all samples voluntarily gave their written informed consent to take part in their respective study and gave permission to analyze their data 2.1. Participants in any subsequent study. All studies complied with the Declaration of Helsinki and no remuneration was offered for participating in any of The dataset for this study stemmed from six non-clinical samples them. Data from all samples were obtained from different research from the Spanish general population. Characteristics of each sample projects described below. The main researchers of each project are shown in Table 1. Overall, participants were primarily women and provided data that has not been previously analyzed or published in university students. Sample 1 comprised a convenience sample of any scientific journal. undergraduates from the University of Jaume I (Castellón, Spain). Sample 1 participants were from a research project about the Sample 2 comprised individuals with previous meditation experience association between meditation practice and values-related behaviors. from the University of Zaragoza community (Zaragoza, Spain). The main aim was to examine the processes involved in that Sample 3 comprised participants that took part in an efficacy study of association. A cross-sectional design was used. Participants were a brief mindful eating induction on food choices and intake at the recruited mainly through advertisements in several Spanish websites Basque Culinary Center in Spain (Allirot et al., 2018). Participants in about mindfulness, meditation, and psychology (scientific Sample 4 were recruited from the University of Zaragoza for the associations, mindfulness associations, monasteries, etc.), as well as psychometric study on the Compassion Practice Quality Scale on non-professional social networks (i.e., Facebook). Participants (Navarrete et al., 2021b). Sample 5 was composed of subjects from an completed an online assessment protocol. Complementary ongoing study about compassion practice quality at the University of information about this research can be found in its main publication Valencia (Valencia, Spain). Finally, Sample 6 comprised a convenience (Franquesa et al., 2017). TABLE 1 Participants characteristics for included samples. TMS SMS TMS and SMS Characteristics Sample 1 Sample 2 Sample 3 Sample 4 Sample 5 Sample 6 (n=119) (n=24) (n=70) (n=69) (n=84) (n=42) Gender (women): n (%) 92 (77.3) 18 (75) 70 (100) 50 (72.50) 65 (77.40) 26 (61.90) Age (in years): M (SD) 20.36 (3.13) 52.59 (8.32) 35.30 (10.68) 35.77 (11.29) 31.43 (12.87) 33.81 (9.77) Previous experience in 27 (22.7) 24 (100) 0 (0) 32 (46.40) 37 (44) 13 (31) meditation practice (yes): n (%) Level of education: n (%) Some school education 0 (0) 0 (0) n/a 8 (11.60) 1 (1.20) 0 (0) High school and/or vocational 0 (0) 0 (0) n/a 7 (10.10) 7 (8.30) 8 (19) education University degree/professional 119 (100) 24 (100) n/a 54 (78.30) 76 (90.50) 34 (81) qualification Frontiers in Psychology 03 frontiersin.org Navarrete et al. 10.3389/fpsyg.2023.1212036 Sample 2 participants underwent a 1-month Vipassana meditation to certain thoughts, feelings or sensations”) and decentering (7 items; retreat organized by a master’s degree course in mindfulness in the e.g., “I experienced myself as separate from my changing thoughts and University of Zaragoza (Spain). Individuals who had confirmed their feelings”) factors. The time frame was adapted when the TMS was also presence at the retreat were sent a letter inviting them to participate in administered before meditation. Higher scores (ranging from 0 to 24 a longitudinal study aimed to assess changes in mindfulness, well- scores in curiosity subscale; ranging from 0 to 28 scores of decentering being, and prosocial personality traits. Participants answered different subscale) indicate higher degree of state mindfulness with respect to measures in the paper-and-pencil format. Concretely, the TMS was meditation practice. administered immediately before the retreat opening and at the end of the retreat. During the retreat, participants practiced open 2.3.3. State mindfulness scale monitoring and focused attention meditations (8–9 h of daily The SMS (Tanay and Bernstein, 2013) is a 21-item self-report meditative practice) and had 1–2 h of teachings. Complementary measure with a 5-point Likert-type scale from 1 (not at all) to 5 (very information about this study can be found in its main publication well). It assesses state mindfulness during the previous 15 min (after (Montero-Marin et al., 2016). meditation practice or other activity) and scores load into state Sample 3 participants were women from a longitudinal study mindfulness of mind (15 items; e.g., “I was aware of different about the effect of a single mindful eating induction on subsequent emotions that arose in me”) and body (6 items; e.g., “I noticed food choices and intake (Allirot et al., 2018). Participants were physical sensations come and go”). In addition, a total score can recruited through advertisements in social media. Included be computed (ranging from 21 to 105 scores). The time frame was participants completed a screening assessment through an online adapted when the SMS was also administered before meditation. survey system. Only baseline data was used in the present study. Higher scores (ranging from 15 to 75 scores in mind subscale; Complementary information about this research can be found in its ranging from 6 to 30 scores of body subscale) indicate greater levels main publication (Allirot et al., 2018). of state mindfulness. Sample 4 participants were recruited from the University of Zaragoza for the psychometric validation study on the Compassion 2.3.4. Five facets mindfulness questionnaire Practice Quality Scale (Navarrete et al., 2021b). Sample 5 participants The FFMQ (Baer et al., 2006) is a 39-item self-report measure with took part in an ongoing study aimed to validate a short mental a 5-point Liker-type scale from 1 (never or very rarely true) to 5 (very imagery skills training and evaluate whether it improves the quality of often or always true). It contains five scales of trait mindfulness: compassion practice. Participants of both samples underwent a observing, describing, acting with awareness, non-judging of inner compassion-based meditation and a loving-kindness meditation, experience, and non-reactivity to inner experience. The higher the respectively. All participants completed pre- and post-test assessments scores are, the higher the levels of trait mindfulness. The Spanish through an online survey system. Complementary information about version of the original 39-item version (facets ranging from 8 to 40 the research line can be found in its main publication (Navarrete scores except for non-reactivity, which ranges from 7 to 35 scores; et al., 2021b). Cebolla et al., 2012) and the 15-item version (facets ranging from 3 to Sample 6 participants were recruited from groups of 15 scores; Gu et al., 2016; Feliu-Soler et al., 2021) were used. In this Metacognition-Based Mindfulness and Meditation Program sample, the scores showed adequate internal consistency with conducted at the University of Jaume I (Castellón, Spain) aimed at Cronbach’s alpha ranging from 0.70 to 0.87 in all facets of the reducing stress and promoting wellbeing in the university community FFMQ-39 and Cronbach’s alpha ranging from 0.72 to 0.85 in all facets (Ortet et al., 2020). Participants were recruited through advertisements of the FFMQ-15, except for observing (α = 0.56). in social media sites and/or University communication channels. Only cross-sectional data was used for the present study (i.e., the TMS and 2.3.5. The experiences questionnaire SMS at pre-intervention). Participants were assessed through paper- The experiences questionnaire (EQ; Fresco et al., 2007) is a and-pencil. Complementary information about this study can 20-item self-report measure that contains two scales: one for be found in its main publication (Ortet et al., 2020). decentering (11 items) and one for rumination (9 items). Only the first one (EQ-Decentering) was used, in which participants rate items on a 7-point Likert-type scale from 1 (never) to 7 (all the time). A higher 2.3. Measures score indicates a higher degree of decentering (ranging from 7 to 77 scores). The Spanish version was used (Soler et al., 2014). In this 2.3.1. Sociodemographic data sample, the EQ showed adequate internal consistency (α = 0.83). Data was collected on participants’ age, gender, and education level. Additionally, we collected data on previous meditation 2.3.6. Non-attachment scale experience (yes or no question). The non-attachment scale (NAS; Sahdra et al., 2010) contains 30 items with a 6-point Liker-type scale from 1 (disagree strongly) to 6 2.3.2. Toronto mindfulness scale (agree strongly) to evaluate non-attachment (e.g., “I can let go of The TMS (Lau et al., 2006) is a 13-item self-report measure with regrets and feelings of dissatisfaction about the past”). The Spanish a 5-point response scale ranging from 0 (not at all) to 4 (very much). 7-item version was used (Feliu-Soler et al., 2016). Higher scores It assesses state mindfulness in the immediately preceding meditation indicate higher non-attachment level (ranging from 7 to 42 scores). practice and scores load into the curiosity (6 items; e.g., “I was curious In this sample, the NAS showed adequate internal consistency about what I might learn about myself by taking notice of how I react (α = 0.76). Frontiers in Psychology 04 frontiersin.org Navarrete et al. 10.3389/fpsyg.2023.1212036 2.3.7. Depression, anxiety, and stress scale assessed scale: a coefficient lower than 0.30 indicates that an item is The depression, anxiety, and stress scale (DASS-21; Henry and measuring something different from the scale as a whole Crawford, 2005) is a 21-item self-report measure scored on a 4-point (DeVellis, 1991). Likert scale ranging from 0 (did not apply to me at all) to 3 (applied to Then, Confirmatory Factor Analyses (CFAs) with diagonally me very much, or most of the time). It measures depression (7 items; weighted least squares (WLSMV) as the estimation method were e.g., “I felt that life wasn’t worthwhile”), anxiety (7 items; e.g., “I felt conducted for assessing dimensionality. The minimum sample size I was close to panic”), and stress (7 items; e.g., “I found it difficult to needed was achieved considering that samples equal or above 100 relax”). A total score measuring psychological distress can participants are enough for analyzing simple models (Kline, 2015). be calculated (ranging from 0 to 63 scores). The higher the scores are The correlated two-factor model of the TMS (curiosity and (each subscale ranging from 0 to 21 scores), the higher the levels of decentering) was tested to replicate Lau et al. (2006) with the data psychopathological symptoms will be. The Spanish version was used from Sample 1. Additionally, a one-factor model with all items loading here (Daza et al., 2002). In this sample, the DASS-21 showed adequate on one latent factor of state mindfulness, a bifactor model with all internal consistency for the depression (α = 0.86), anxiety (α =0.79), items loading on one general latent factor and on two uncorrelated and stress (α = 0.79) factors, as well as for the general distress factor factors, and a hierarchical two-factor model including an overarching (α = 0.92). mindfulness factor were tested. All models were calculated with and without the correlated residuals between items 5 and 6, 3 and 13, and 2.3.8. International positive and negative affect 12 and 13 that Ireland et al. (2019) and Yu et al. (2021) proposed in schedule short form their psychometric studies. The positive and negative affect schedule short form (PANAS; In the case of the SMS’s factorial structure, we examined the Thompson, 2007) is 10-item self-reporting measure that contains two goodness-of-fit of the original structure (hierarchical two-factor 5-item Likert scales: one for positive affect and one for negative affect. model) reported by Tanay and Bernstein (2013), in addition to the It has a 5-point response format ranging from 1 (very slightly or not following models in Samples 3, 4 and 5: a one-factor model with all at all) to 5 (extremely). Higher scores indicate higher positive and items loading on one state mindfulness factor; a correlated two-factor negative affect (each one ranging from 5 to 25 scores). An ad-hoc model; and finally, a bifactor model with all items loading on one version was used, with the items extracted from the Spanish long- general latent factor and on two uncorrelated specific factors. All version PANAS (Sandín et al., 1999). In this sample, the scores showed models were tested with and without the correlated residuals between adequate internal consistency for the positive (α = 0.91) and negative items 3 and 12, 6 and 11, 10 and 16, and 15 and 16 proposed by Tanay (α = 0.73) scales. and Bernstein (2013). In order to test the fit of the proposed models, the following 2.3.9. Forms of self-criticizing/attacking and indices were calculated and interpreted using conservative and liberal self-reassuring scale short form cut-offs (Hu and Bentler, 1999; Schermelleh-Engel et al., 2003): the The forms of self-criticizing/attacking and self-reassuring scale chi-square ratio (χ2/df) ≤ 3, the comparative fit index (CFI) and the short form (FSCRS-SF; Sommers-Spijkerman et al., 2018) is a self- Tucker-Lewis index (TLI) ≥ 0.95 or 0.90, the root mean square error report measure that assesses two forms of self-criticism (inadequate approximation (RMSEA) ≤ 0.06 or 0.10, and the weighted root mean self and hated self) and self-reassurance (reassured self) with its 14 square residual (WRMR) ≈ 1. A practical improvement in model-fit items being rated on a 5-point Likert scale ranging from 0 (not at all approach was used to compare the models (difference of 0.01 or like me) to 4 (extremely like me). Higher scores indicate higher self- greater in TLI; Vandenberg and Lance, 2000). criticism (ranging from 0 to 20 scores in inadequacy subscale; ranging Following the methodology proposed by Cuesta-Vargas et al. from 0 to 16 scores of self-hate subscale) and self-reassurance (ranging (2018, 2020), before assembling the TMS (Sample 1 and 2) and SMS from 0 to 20 scores). The Spanish version was used here (Navarrete (Samples 3–5) datasets, we tested whether the subsamples were et al., 2021c). In this sample, the scores showed adequate internal homogeneous concerning the structure of the items represented by consistency for the inadequate self (α = 0.81), hated self (α = 0.80), and the covariances or correlations. Regarding the heterogeneity test for reassured self (α = 0.79) scales. the assembled datasets, the RMSEA was chosen as the main indicator Participants from Sample 1 and 2 completed the TMS, participants following the cut-off criteria described above (Cuesta-Vargas et al., from samples 3, 4, and 5 answered to the SMS, and participants from 2018, 2020). Sample 6 completed both. In addition, Sample 1 completed the The internal consistency of the scales was determined by FFMQ-15, EQ–Decentering, NAS, and DASS-21, Sample 3 completed calculating Cronbach’s α, where coefficients equal to or above 0.60 the FFMQ, Sample 4 completed the PANAS and FSCRS-SF and indicated adequate internal consistency for exploratory research and Sample 5 participants the FSCRS-SF. equal to or above 0.70 for confirmatory research (Hair et al., 1998). In addition, coefficients H, omega (ω), and omega-hierarchical (ωh) were calculated to evaluate the reliability of the TMS and SMS from a 2.4. Data analyses bifactor approach (Rodriguez et al., 2016; Flora, 2020). The coefficient H measures construct replicability, with values higher than 0.80 Firstly, descriptive statistics (mean [M], standard deviation [SD], indicating a well-defined latent variable (Hancock and Mueller, 2001). skewness, and kurtosis) were computed. In addition, corrected item- Regarding the general factor, comparing omega and omega- total correlations (rtot) were calculated for TMS and SMS items to hierarchical indicates the reliability of the general score controlling for examine how each item contributed to the overall scale. The rtot the specific factors. With regard to the specific factors, it provides serves the purpose of identifying items that are not explicative for the information about their ability to reliably measure the variance by Frontiers in Psychology 05 frontiersin.org Navarrete et al. 10.3389/fpsyg.2023.1212036 themselves controlling for the general factor. Thus, low omega- correlated error terms suggested by the authors was the best-fitting hierarchical values (<0.50) mean that the computation of specific model (χ2/df = 3.05; p < 0.001; CFI = 0.96; TLI = 0.95; RMSEA = 0.10 subscale scores are not recommended (Brunner et al., 2012). with CI 90% [0.09, 0.11]; WRMR = 0.99), showing a better fit than the To investigate convergent/discriminant validity, Pearson bifactor solution without pairs of correlated error terms (χ2/df = 3.36; correlation coefficients between TMS and FFMQ-15, EQ– p < 0.001; CFI = 0.95; TLI = 0.94; RMSEA = 0.10 with CI 90% [0.09, Decentering, NAS, and DASS-21 were calculated with the data of 0.11]; WRMR = 1.08). The standardized factor loadings of this bifactor Sample 1. In addition, correlations between SMS and FFMQ model ranged from.59 (item 14) to.84 (item 11), see Figure 2 for (Sample 3), PANAS (Sample 4), and FSCRS-SF (Samples 4 and 5) more details. were calculated. Finally, correlations between the TMS and SMS were calculated with the data of Sample 6. The strength of the correlations was interpreted following Cohen’s guidelines (Cohen, 3.3. Reliability 1988): small (r = 0.10–0.29), medium (r = 0.30–0.49), and large (r = 0.50–1.00). Internal consistency of the TMS was adequate with Cronbach’s α Finally, sensitivity to change was assessed by conducting three and McDonald’s ω equal to or greater than.60 (αcuriosity = 0.85; paired-samples t-test to evaluate the impact of the 1-month αdecentering = 0.65; ωcuriosity = 0.85; ωdecentering = 0.65). Vipassana meditation retreat on the TMS scores in Sample 2, a Regarding the SMS, the following coefficient H, ω, and ωh values compassion-based meditation in Sample 4 participants’ SMS scores, were obtained: 0.97/0.97/0.96 (SMS-total), 0.51/0.97/0.01 (SMS- and a loving-kindness meditation on the SMS scores of participants mind), and.55/0.89/0.15 (SMS-body). The difference between ω and from Sample 5. ωh for SMS-mind and SMS-body suggested that the reliability of both Descriptive and correlation analyses and paired-samples t-test specific factors was very poor when controlling for the general factor were performed with SPSS version 26. CFA was performed with of state mindfulness. Mplus version 7.4. 3.4. Convergent/discriminant validity 3. Results Relationships between the TMS subscales (curiosity and decentering) and the other questionnaires are shown in Table 5. 3.1. Item analysis Results showed that TMS-curiosity was positively correlated with EQ-decentering (r = 0.20; p = 0.032), being a correlation of Preliminary analyses showed that the items scores of the TMS and small magnitude. TMS-curiosity was not significantly associated SMS were normally distributed, as assessed by levels of skewness and with FFMQ-15 facets. Moreover, TMS-decentering was positively kurtosis (see Tables 2, 3). In addition, the rtot for both scales was correlated with EQ-decentering (r = 0.21; p = 0.023) and greater than 0.30, thus suggesting adequate homogeneity of the items, NAS-non-attachment (r = 0.19; p = 0.039). As well, except for item 4 of the TMS. However, this item was retained because TMS-decentering was correlated with FFMQ-non-reactivity the scale’s overall Cronbach’s α and McDonald’s ω were adequate. (r = 0.28; p = 0.002). As shown in Table 6, there was a significant association between FFMQ-observing and SMS-total (r = 0.35; p = 0.004), SMS-mind 3.2. Dimensionality (r = 0.33; p = 0.007), and SMS-body (r = 0.35; p = 0.004). As well, SMS-body significantly correlated with FFMQ-non-reactivity. In The fit indices for the models tested in the TMS are shown in addition, PANAS-positive affect factor was significantly associated Table 4. Samples 1 and 2 were not homogeneous concerning the with SMS-total (r = 0.44; p < 0.001), SMS-mind (r = 0.43; p < 0.001), structure of the TMS items (RMSEA = 0.12, 90% CI [0.09–0.14]), so and SMS-body (r = 0.40; p = 0.001). Finally, the SMS factors were the CFA of the TMS was performed with data from Sample 1. The negatively associated with the two factors of self-criticism, FSCRS- best-fitting model was the original correlated two-factor model inadequate self (SMS-total: r = −0.21; p = 0.017; SMS-mind: proposed by Lau et al. (2006), though including the three pairs of r = −0.21; p = 0.017; and SMS-body: r = −0.18; p = 0.04) and FSCRS- correlated error terms proposed by Ireland et al. (2019) and Yu et al. hated self (SMS-total: r = −0.23; p = 0.010; SMS-mind: r = −0.21; (2021) (χ2/df = 2.19; p < 0.001; CFI = 0.93; TLI = 0.91; RMSEA = 0.10 p = 0.019; and SMS-body: r = −0.25; p = 0.005). In this line, there was with CI 90% [0.08, 0.12]; WRMR = 0.91). The standardized factor a positive association between FSCRS-reassured self and SMS-total loadings of this two-factor model ranged from.24 (item 8) to.74 (item (r = 0.36; p < 0.001), SMS-mind (r = 0.35; p < 0.001), and SMS-body 12), see Figure 1 for more details. Preliminary analyses showed that (r = 0.33; p < 0.001). Overall, the magnitude of these correlations the factor structures with the correlated residuals of Ireland et al. was moderate. (2019) and Yu et al. (2021) separately were not supported by our data. Finally, there were statistically significant correlations between With regard to the SMS, when Samples 3, 4, and 5 of the dataset TMS-curiosity and SMS-total (r = 0.48; p = 0.001), SMS-mind (r = 0.48; were tested for heterogeneity, they were found to be relatively p = 0.001), and SMS-body (r = 0.36; p = 0.019). As well, homogeneous (RMSEA = 0.10, 90% CI [0.09–0.12]). As displayed in TMS-decentering was significantly associated with SMS-total (r = 0.51; Table 4, the hierarchical two-factor model (with and without pairs of p = 0.001), SMS-mind (r = 0.50; p = 0.001), and SMS-body (r = 0.40; correlated error terms) proposed by Tanay and Bernstein (2013) was p = 0.008). Overall, the magnitude of these correlations was not supported. Instead, the bifactor model with the four pairs of moderate-to-large. Frontiers in Psychology 06 frontiersin.org Navarrete et al. 10.3389/fpsyg.2023.1212036 TABLE 2 Descriptive statistics of the Toronto Mindfulness Scale and standardized factor loadings (λ) for the correlated two-factor model (+ θ5-6, θ3-13, θ12-13 free). TMS items M (SD) S K rtot λ Factor I. Curiosity. 3. I was curious about what I might learn about myself by taking notice of how I react to certain 2.42 (1.09) −0.58 −0.29 0.60 0.73 thoughts, feelings or sensations. [Sentía curiosidad sobre qué podía aprender de mí mismo/a, dándome cuenta de cómo reacciono habitualmente ante ciertos pensamientos, emociones o sensaciones.] 5. I was curious to see what my mind was up to from moment to moment. [Sentí curiosidad por ver 2.50 (1.10) −0.36 −0.75 0.68 0.73 qué hacía mi mente momento a momento.] 6. I was curious about each of the thoughts and feelings that I was having. [Sentí curiosidad hacia 2.39 (1.07) −0.45 −0.53 0.68 0.70 cada uno de los pensamientos y emociones que estaba teniendo en ese momento.] 10. I remained curious about the nature of each experience as it arose. [Observé con curiosidad 2.72 (0.95) −0.51 −0.31 0.54 0.72 cómo era la experiencia que estaba teniendo en ese momento.] 12. I was curious about my reactions to things. [Sentía curiosidad por mis reacciones ante aquello 2.37 (1.05) −0.43 −0.58 0.67 0.74 que sucedía en ese momento.] 13. I was curious about what I might learn about myself by just taking notice of what my attention 2.55 (1.08) −0.60 −0.20 0.64 0.65 gets drawn to. [Estaba interesado/a en descubrir qué podía aprender de mí mismo/a simplemente siendo consciente de aquello que atraía mi atención en ese momento.] Factor II. Decentering 1. I experienced myself as separate from my changing thoughts and feelings. [Me percibí a mí 1.73 (1.18) 0.03 −0.91 0.32 0.46 mismo/a como algo separado de mis sentimientos y pensamientos cambiantes.] 2. I was more concerned with being open to my experiences than controlling or changing them. 2.19 (0.95) −0.10 −0.08 0.37 0.52 [Estaba más interesado/a en estar abierto a lo que me sucedía en ese momento que en tratar de controlar o cambiar esa experiencia.] 4. I experienced my thoughts more as events in my mind than as a necessarily accurate reflection of 2.06 (1.07) −0.33 −0.70 0.28 0.34 the way things ‘really’ are. [Experimentaba mis pensamientos más como sucesos mentales que como un reflejo preciso de cómo son las cosas en realidad.] 7. I was receptive to observing unpleasant thoughts and feelings without interfering with them. 2.38 (1.14) −0.33 −0.82 0.51 0.89 [Estaba receptivo a observar mis pensamientos y sentimientos desagradables que pudieran aparecer sin necesidad de interferir en ellos.] 8. I was more invested in just watching my experiences as they arose, than in figuring out what they 2.32 (1.13) −0.41 −0.61 0.31 0.24 could mean. [Estaba más dedicado a simplemente observar lo que me sucedía que en interpretar su posible significado.] 9. I approached each experience by trying to accept it, no matter whether it was pleasant or 2.52 (1.08) −0.47 −0.44 0.38 0.52 unpleasant. [Intenté aceptar cualquier experiencia que estuviera teniendo en ese momento, sin importar si esta era agradable o desagradable.] 11. I was aware of my thoughts and feelings without overidentifying with them. [Era consciente de 1.95 (1.17) 0.00 −0.78 0.35 0.40 mis pensamientos y emociones sin identificarme demasiado con ellos.] N = 119. TMS, Toronto Mindfulness Scale; M, mean; SD, standard deviation; S, skewness; K, kurtosis. Rtot, corrected item-total correlations. Items scores range from 0 (not at all) to 4 (very much). 3.5. Sensitivity to change SMS-body (t = −5.07, p < 0.001, d = 0.97) scores. Regarding the participants who performed a loving-kindness meditation, significant Table 7 shows the results of the paired-samples t-tests evaluating changes in SMS scores (moderate effect sizes) from pre-meditation to the impact of different meditations on participants’ TMS and SMS post-meditation assessment were detected in the SMS-total (t = −7.22, scores. Statistically significant improvements in TMS-curiosity p < 0.001, d = 0.70), SMS-mind (t = −7.13, p < 0.001, d = 0.69), and (t = −3.30, p = 0.003, d = 0.63) and TMS-decentering (t = −4.56, SMS-body (t = −8.60, p < 0.001, d = 0.67) scores. p < 0.001, d = 0.88) scores (with moderate-to-large effect sizes) were detected at the end of the 1-month Vipassana meditation retreat. Similarly, there were statistically significant changes in the SMS scores 4. Discussion of participants who performed a compassion-based meditation (moderate-to-large effect sizes), as reflected in SMS-total (t = −7.10, In this study, we evaluated the psychometric properties of the p < 0.001, d = 0.90), SMS-mind (t = −7.63, p < 0.001, d = 0.97), and Spanish versions of the TMS and SMS, which assess state mindfulness, Frontiers in Psychology 07 frontiersin.org Navarrete et al. 10.3389/fpsyg.2023.1212036 TABLE 3 Descriptive statistics of the State Mindfulness Scale and standardized factor loadings (λ) for the bifactor model. SMS items M (SD) S K rtot λ gen λ spec Factor I. State mindfulness of mind 3.52 (1.08) −0.46 −0.48 0.70 0.74 0.28 1. I was aware of different emotions that arose in me. [Fui consciente de las diferentes emociones que surgieron en mí.] 3.57 (1.18) −0.76 −0.26 0.74 0.78 0.35 2. I tried to pay attention to pleasant and unpleasant sensations. [Intenté atender a las sensaciones agradables y desagradables.] 3. I found some of my experiences interesting. [Encontré interesantes algunas de 3.52 (1.21) −0.58 −0.60 0.63 0.68 0.23 mis experiencias.] 4. I noticed many small details of my experience. [Me di cuenta de muchos 3.13 (1.25) −0.15 −1.01 0.77 0.81 0.25 pequeños detalles de mi experiencia.] 5. I felt aware of what was happening inside of me. [Fui consciente de lo que pasaba 3.26 (1.18) −0.33 −0.77 0.75 0.80 0.25 dentro de mí.] 6. I noticed pleasant and unpleasant emotions. [Me di cuenta de emociones 3.58 (1.13) −0.72 −0.31 0.76 0.80 0.21 agradables y desagradables.] 7. I actively explored my experience in the moment. [Exploré activamente mi 3.22 (1.34) −0.38 −1.08 0.77 0.82 0.31 experiencia en el momento presente.] 10. I felt that I was experiencing the present moment fully. [Sentí que estaba 3.06 (1.29) −0.21 −1.09 0.77 0.81 0.17 experimentando plenamente el momento presente.] 11. I noticed pleasant and unpleasant thoughts. [Me di cuenta de pensamientos 3.53 (1.12) −0.65 −0.32 0.76 0.84 −0.17 agradables y desagradables.] 12. I noticed emotions come and go. [Me di cuenta de emociones yendo y viniendo.] 3.17 (1.22) −0.28 −0.95 0.70 0.79 −0.31 15. I had moments when I felt alert and aware. [Tuve momentos en los que me sentí 3.35 (1.20) −0.47 −0.74 0.75 0.78 0.02 alerta y consciente.] 16. I felt closely connected to the present moment. [Me sentí íntimamente 3.16 (1.25) −0.27 −0.91 0.75 0.78 0.14 conectado al momento presente.] 17. I noticed thoughts come and go. [Me di cuenta de pensamientos yendo y 3.34 (1.14) −0.35 −0.66 0.66 0.75 −0.48 viniendo.] 19. I was aware of what was going on in my mind. [Fui consciente de lo que sucedía 3.40 (1.17) −0.48 −0.66 0.75 0.82 −0.09 en mi mente.] 20. It was interesting to see the patterns of my thinking. [Fue interesante ver los 3.13 (1.30) −0.19 −0.99 0.75 0.81 −0.07 patrones de mi pensamiento.] Factor II. State mindfulness of body 8. I clearly physically felt what was going on in my body. [Me di cuenta claramente 3.00 (1.22) −0.15 −0.92 0.68 0.72 0.29 de lo que sucedía físicamente en mi cuerpo.] 9. I changed my body posture and paid attention to the physical process of moving. 2.61 (1.36) 0.21 −1.28 0.55 0.60 0.23 [Cambié la postura de mi cuerpo y presté atención al proceso físico del movimiento.] 13. I noticed various sensations caused by my surroundings (e.g., heat, coolness, 3.36 (1.24) −0.41 −0.81 0.60 0.62 0.39 the wind on my face). [Noté varias sensaciones causadas por el entorno (p. ej.: calor, frio, el viento en mi cara).] 14. I noticed physical sensations come and go. [Me di cuenta de sensaciones físicas 2.87 (1.17) 0.05 −0.79 0.58 0.59 0.68 yendo y viniendo.] 18. I felt in contact with my body. [Sentí que estaba en contacto con mi cuerpo.] 3.05 (1.19) −0.11 −0.88 0.76 0.81 0.14 21. I noticed some pleasant and unpleasant physical sensations. [Me di cuenta de 3.31 (1.15) −0.32 −0.79 0.67 0.74 0.07 algunas sensaciones físicas agradables y desagradables.] N = 223. SMS, State Mindfulness Scale; M, mean; SD, standard deviation; S, skewness; K, Kurtosis. Rtot, corrected item-total correlations. Factor loadings on general state mindfulness factor (λ gen) and specific factors (λ spec). Items scores range from 1 (not at all) to 5 (very well). Frontiers in Psychology 08 frontiersin.org Navarrete et al. 10.3389/fpsyg.2023.1212036 TABLE 4 Fit indices for the Toronto Mindfulness Scale and State Mindfulness Scale models. Scale Model χ2*** df CFI TLI RMSEA [90%CI] WRMR One-factor 231.38 65 0.846 0.815 0.147 [0.126, 0.167] 1.227 TMS One-factor (+ θ5-6, θ3-13, θ12-13 freea) 172.38 62 0.898 0.871 0.122 [0.101, 0.144] 1.032 (n = 119) Correlated Two-factor 176.23 64 0.896 0.873 0.121 [0.100, 0.143] 1.076 Correlated Two-factor (+ θ5-6, θ3-13, θ12-13 free ) a 133.98 61 0.932 0.913 0.100 [0.077, 0.123] 0.908 One-factor 809.94 189 0.928 0.921 0.121 [0.113, 0.130] 1.462 One-factor (+ θ3-12, θ6-11, θ10-16, θ15-16 freeb) 738.62 185 0.936 0.928 0.116 [0.107, 0.125] 1.377 SMS Correlated Two-factor 771.81 188 0.933 0.925 0.118 [0.109, 0.127] 1.414 (n = 223) Correlated Two-factor (+ θ3-12, θ6-11, θ10-16, θ15-16 free ) b 705.41 184 0.940 0.931 0.113 [0.104, 0.122] 1.333 Bifactor 564.27 168 0.954 0.943 0.103 [0.094, 0.112] 1.079 Bifactor (+ θ3-12, θ6-11, θ10-16, θ15-16 free ) b 500.61 164 0.961 0.950 0.096 [0.086, 0.106] 0.993 χ2 (df), chi-square (degrees of freedom); CFI, Comparative Fit Index; TLI, Tucker-Lewis Index; RMSEA, root mean square error approximation; 90% CI, 90% confidence interval of the RMSEA; WRMR, weighted root means square residual; TMS, Toronto Mindfulness Scale; SMS, State Mindfulness Scale. The chosen estimator was diagonally weighted least squares (WLSMV). Indices for the TMS bifactor and the hierarchical two-factor model with and without correlated residuals models are not shown because the Mplus models did not converge. Indices for the SMS hierarchical two-factor with and without correlated residuals models are not shown because the Mplus model did not converge. aCorrelated residuals among items as proposed by Ireland et al. (2019) and Yu et al. (2021). bCorrelated residuals among items as proposed by Tanay and Bernstein (2013). ***p < 0.001. TABLE 5 Convergent/discriminant validity of the Toronto Mindfulness Scale (n=119). Measure TMS M (SD) Curiosity Decentering FFMQ-15 Observing/noticing (3–15) 9.55 (2.84) 0.15 0.05 Describing (3–15) 9.83 (2.98) 0.11 −0.06 Acting with awareness (3–15) 9.53 (2.65) 0.00 −0.07 Non-judging of experience (3–15) 9.86 (3.06) −0.06 −0.13 Non-reactivity to inner experience 8.81 (2.51) 0.11 0.28** (3–15) EQ-Decentering (7–77) 34.56 (6.76) 0.20* 0.21* NAS (7–42) 26.45 (4.84) 0.14 0.19* DASS-21 (0–63) 20.24 (11.85) −0.12 0.04 Depression (0–21) 5.66 (4.72) −0.10 0.08 Anxiety (0–21) 6.10 (4.40) −0.15 0.04 Stress (0–21) 8.45 (4.42) −0.06 −0.02 The numbers in brackets beside subscale names is the range of possible scores. TMS, Toronto Mindfulness Scale; FFMQ-15, Five Facets Mindfulness Questionnaire (15-item version); EQ, Experiences Questionnaire – Decentering; NAS, Nonattachment scale; DASS-21, Depression Anxiety Stress Scale (21-item version). *p < 0.05; **p < 0.01. in pooled non-clinical samples from the Spanish general population. original authors, who found support for a “similar factor structure as Regarding Hypothesis 1, the TMS showed a correlated two-factor originally reported” (Ruimi et al., 2022, p. 13). structure (curiosity and decentering), consistent with the original Regarding reliability (Hypotheses 2), the TMS scores demonstrated model (Lau et al., 2006), though with three pairs of correlated error adequate internal consistency as expected, with similar values to those terms proposed in previous psychometric studies (Ireland et al., 2019; obtained in previous studies (Lau et al., 2006; Yu et al., 2021). In that Yu et al., 2021). So far, the correlated two-factor structure has been sense, it should be noted that we have reported McDonald’s ω for the considered the best factorial model and previous studies has not first time as an estimator of internal consistency of this scale. With shown evidence in favor of the presence of a general factor (Lau et al., respect to the SMS, although internal consistency analysis suggested 2006; Ireland et al., 2019; Yu et al., 2021). Regarding the SMS, a that the total score was a reliable measure of state mindfulness, in bifactor model was confirmed, instead of the hierarchical two-factor contrast with Andrade et al. (2019), a small portion of reliably model proposed by Tanay and Bernstein (2013). Even so, both factor measured variance could be attributed to body and mind factors. structures theoretically allow the scoring of the SMS subscales According to our results, despite the multidimensionality of the items, (mindfulness of body and mind) and a general factor of the whole these specific factors showed low reliability because they seem to scale (Brunner et al., 2012). In fact, this result might be in line with be tapped primarily by the general factor of state mindfulness. The recent unpublished reports about dimensionality of the SMS by the discrepancy between the present findings and those of Andrade et al. Frontiers in Psychology 09 frontiersin.org Navarrete et al. 10.3389/fpsyg.2023.1212036 (2019) regarding the SMS might be due to the use of different model in Andrade et al. (2019) vs. a bifactor model here. In a approaches to model the structure of the latent variables, a hierarchical hierarchical model, the reliability estimates of subfactors are typically expected to be higher compared to a bifactor model because the subfactors share a substantial amount of common variance due to their direct dependence on the higher-level factor. On the contrary, the specific factors in bifactor models are intentionally designed to capture specific and unique dimensions of the construct, and they may not share as much common variance or exhibit high internal consistency (Reise et al., 2013). The presence of a strong general construct that explains much more variance than the specific constructs is a common circumstance in many self-report measures (Brunner et al., 2012; Luciano et al., 2014). Therefore, it is not recommended to compute state mindfulness of bodily sensations and state mindfulness of mind scores separately because an interpretation of a person’s level in any of both specific domains involves great uncertainty. Nevertheless, it might be useful to compute the subscales scores when complex measurement models are required (Reise et al., 2013), for instance when testing Tanay and Bernstein’s (2013) definition of state mindfulness. With respect to convergent/discriminant validity of the TMS (Hypothesis 3), these results showed that the TMS scores were not significantly related to the facets of trait mindfulness, except for a weak association between decentering scores and non-reactivity to inner experience. Similarly, Ireland et al. (2019) found that only decentering was significantly associated to trait mindfulness (measured with the Mindful Attention Awareness Scale; Brown and Ryan, 2003). Moreover, Yu et al. (2021) reported a significant correlation between both TMS subscales scores and only observing and non-reacting. In addition, TMS scores were positively associated to decentering and non-attachment, except for curiosity with non-attachment. Similarly, Lee et al. (2010) found a significant correlation of TMS scores with decentering assessed with the FIGURE 1 Two-factor Model of the Toronto Mindfulness Scale (TMS) obtained EQ. However, no previous studies included the non-attachment in the CFA. construct, but similar ones with which curiosity and decentering (TMS) were significantly related, that is, psychological mindedness TABLE 6 Convergent/discriminant validity of the State Mindfulness Scale. Measure SMS n M (SD) Total Mind Body FFMQ (Sample 3) Observing/noticing (8–40) 67 27.34 (5.18) 0.35** 0.33** 0.35** Describing (8–40) 67 27.85 (5.09) 0.17 0.15 0.15 Acting with awareness (8–40) 64 28.41 (5.64) 0.18 0.17 0.17 Non-judging of experience (8–40) 66 29.08 (5.87) 0.06 0.01 0.15 Non-reactivity to inner experience 67 20.73 (3.72) 0.22 0.17 0.29* (7–35) PANAS (Sample 4) Positive affect (5–25) 63 12.68 (4.36) 0.44** 0.43** 0.40** Negative affect (5–25) 63 8.44 (3.23) −0.09 −0.10 −0.07 FSCRS-SF (Samples 4 and 5) Inadequate self (0–20) 129 8.09 (4.55) −0.21* −0.21* −0.18* Hated self (0–16) 130 3.12 (3.59) −0.23** −0.21* −0.25** Reassured self (0–20) 130 12.58 (4.10) 0.36** 0.35** 0.33** The numbers in brackets beside subscale names is the range of possible scores. SMS, State Mindfulness Scale; FFMQ, Five Facets Mindfulness Questionnaire (39-item version); PANAS, Positive and Negative Affect Scale; FSCRS-SF, Forms of Self-Criticizing/Attacking & Self-Reassuring Scale (Short Form). *p < 0.05; **p < 0.01. Frontiers in Psychology 10 frontiersin.org Navarrete et al. 10.3389/fpsyg.2023.1212036 TABLE 7 Means, standard deviations, and paired-samples t-test in TMS and SMS scores. Measure Pre-test Post-test t p Cohen’s d [95% CI] M SD M SD 1-month Vipassana meditation retreat (n = 22) TMS-Curiosity (0–24) 15.64 4.80 19.00 3.55 −3.30 0.003 0.63 [0.02, 1.23] TMS-Decentering 14.68 5.06 20.32 3.99 −4.56 <0.001 0.88 [0.26, 1.50] (0–28) Compassion meditation (n = 49) SMS (21–105) 55.14 19.44 74.98 14.33 −7.10 <0.001 0.90 [0.48, 1.32] SMS-Mind (15–75) 39.31 14.27 54.35 10.26 −7.63 <0.001 0.97 [0.55, 1.39] SMS-Body (6–30) 15.84 5.96 20.63 4.79 −5.07 <0.001 0.66 [0.25, 1.07] Loving-kindness meditation (n = 84) SMS 68.61 17.95 82.79 13.40 −7.22 <0.001 0.70 [0.30, 1.11] SMS-Mind 50.48 13.30 60.58 9.67 −7.13 <0.001 0.69 [0.28, 1.10] SMS-Body 18.13 5.33 22.20 4.61 −8.60 <0.001 0.67 [0.27, 1.08] The numbers in brackets beside subscale names is the range of possible scores. TMS, Toronto Mindfulness Scale; SMS, State Mindfulness Scale. and private self-awareness (Lau et al., 2006; Yu et al., 2021). In a significant increase in state mindfulness levels, as expected. Along addition, TMS scores have not shown a significant association with this line, the TMS and SMS have been able to detect state mindfulness psychopathology symptoms in this study nor in previous ones (Lau changes in a variety of mindfulness psychoeducation and practices et al., 2006; Lee et al., 2010; Yu et al., 2021), except for Ireland et al. (Lau et al., 2006; Tanay and Bernstein, 2013; Ruimi et al., 2022). (2019), who found a significant association between decentering and The main implication of this study is that the Spanish version of DASS-21 scores. the TMS and SMS can be used for state mindfulness assessment in In this line (Hypothesis 4), SMS scores were significantly related intervention research among Spanish participants from the general to positive affect, but not to negative affect, similar to what Andrade population. Overall, both have shown to be reliable measures with et al. (2019) reported. Also, our results showed for the first time a expected patterns of convergent validity and good responsiveness. negative association between state mindfulness and self-criticism. However, these findings must be interpreted understanding the Meanwhile compassion research has shown interest in the influence following limitations. First, the best-fitting CFA models achieved the of self-criticism on compassion states or compassion practice quality standards of good model fit by the narrowest of margins. Indeed, the (Gilbert et al., 2006; Naismith et al., 2018; Navarrete et al., 2021b), higher RMSEA values in the 90% confidence interval suggest that further research is needed to study the influence of self-criticism in there is room for model improvements in both scales. Moreover, the the process of generating mindfulness states and mindfulness variety of samples included in this study might partially bias the meditation practice, specifically to clarify its directionality. results because the recruitment and assessment were independent and Our results showed a significant association between SMS scores different for each one (Podsakoff et al., 2003). In this regard, the TMS and the observing facet of mindfulness, which Tanay and Bernstein and SMS were administered either online or in person and along with (2013) and Andrade et al. (2019) also reported. However, there were different questionnaires. In addition, the study samples were recruited no significant associations between SMS scores and describing by a non-probability (convenience) sampling process. Therefore, it is non-reactivity, or non-judging meanwhile those authors did find them. difficult to determine how well the Spanish population is represented It should be noted that assessing construct validity by correlating both by them, which limits the generalizability of the findings. For instance, trait and state measures might lead to counter-intuitive results (e.g., the samples were not representative of the Spanish general population lack of or inconsistent correlations between state mindfulness and in terms of their gender distribution (more than 70% in each sample facets of trait mindfulness). However, the fact that TMS and SMS were women) and level of education (high proportion of participants scores do not correlate very well with more stable measures (e.g., with university studies). Also, the extent to which our findings can FFMQ or MAAS) probably also indicates that they are actually be generalized to other Spanish-speaking countries might be limited. capturing “state” constructs. That is, state measures should show a Moreover, all the measures used were self-report measures. higher correlation with other state measures than with trait measures Furthermore, the sample sizes were modest, especially for the on a given occasion (Zuckerman, 1983). In that regard, there was a TMS. Although the present samples were enough for CFA analyses significant association between the TMS and SMS scores. As previously according to commonly cited rules of thumb (ratio of 5:10 or a reported, the magnitude was moderate indicating the differences in minimum sample size of 100–200; Brown, 2015), larger samples conceptual aspects of both scales (Tanay and Bernstein, 2013). guarantee higher statistical power and robustness of the models. Regarding sensitivity to change (Hypothesis 5), participants who Regarding sensitivity to change, the studies interventions had not a participated in the 1-month Vipassana meditation retreat, a control group to determine whether the changes were due to the compassion-based meditation or a loving-kindness meditation showed intervention or not. Thus, the changes captured by the paired-samples Frontiers in Psychology 11 frontiersin.org Navarrete et al. 10.3389/fpsyg.2023.1212036 FIGURE 2 Bifactor Model of the State Mindfulness Scale (SMS) obtained in the CFA. t-tests could be partially (not totally) related to the meditations. future research should consider studying the reliability of the SMS in Furthermore, participants were generally female, young, university detail to inform about the possibility of computing the subscale scores. educated, and without previous experience in meditation practice, which might limit the generalizability of the results to the wider population. In this line, future cross-sectional validation studies Data availability statement should recruit a large sample. Then, the factor structure of the TMS and the SMS Spanish versions should be tested to explore potential The data analyzed in this study is subject to the following licenses/ model modifications or alternative explanations to enhance the CFA restrictions: The data that support the findings of this study are models fit. Additionally, it is recommended to conduct replication available on request from the corresponding author. The data are not studies using Spanish samples from various levels of education, age publicly available due to a privacy issue. Requests to access these ranges, and in accordance with the population’s gender ratio. Finally, datasets should be directed to AF-S, albert.feliu@uab.cat. Frontiers in Psychology 12 frontiersin.org Navarrete et al. 10.3389/fpsyg.2023.1212036 Ethics statement role in the analysis and interpretation of data, in the writing of the manuscript, or in the decision to submit the paper for publication. The studies involving human participants were reviewed and approved by the Ethics Committee at the Sant Joan de Déu Foundation (PIC-141-19). The patients/participants provided their written Conflict of interest informed consent to participate in this study. The authors declare that the research was conducted in the absence of any commercial or financial relationships that could Author contributions be construed as a potential conflict of interest. AC-C, JS-M, DP, A-JS-L, JG-C, MD, JS, AC, AF-S, and JL designed and executed the study. JN and MF-M analyzed the data and wrote the Publisher’s note manuscript. All authors reviewed and approved the final version of the manuscript for submission. All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the Funding reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or We are grateful to the CIBER of Epidemiology and Public Health endorsed by the publisher. (CIBERESP CB22/02/00052; ISCIII), CIBER of Mental Health (CIBERSAM), and CIBER of Obesity and Nutrition (CIBEROBN) for their support. JN has a research contract from the Institute of Health Supplementary material Carlos III (ISCIII; ICI20/00080). JS-M has a PFIS predoctoral contract from the ISCIII (FI20/00034). AC-C has a FI predoctoral contract The Supplementary material for this article can be found online from AGAUR (FI_B/00216). AF-S acknowledges the funding from the at: https://www.frontiersin.org/articles/10.3389/fpsyg.2023.1212036/ Serra Húnter program (UAB-LE-8015). The ISCIII did not have any full#supplementary-material References Allirot, X., Miragall, M., Perdices, I., Baños, R. M., Urdaneta, E., and Cebolla, A. Daza, P., Novy, D. M., Stanley, M. A., and Averill, P. (2002). The depression anxiety (2018). Effects of a brief mindful eating induction on food choices and energy intake: stress scale-21: Spanish translation and validation with a Hispanic sample. J. external eating and mindfulness state as moderators. Mindfulness 9, 750–760. doi: Psychopathol. Behav. Assess. 24, 195–205. doi: 10.1023/A:1016014818163 10.1007/s12671-017-0812-0 DeVellis, R. F. (1991). Scale development: Theory and applications. Newbury Park: Sage Andrade, C., Arriaga, P., and Carvalho, M. (2019). The psychometric properties of the Publications, Inc. Portuguese version of the state mindfulness scale. Mindfulness 10, 2661–2672. doi: Feliu-Soler, A., Pérez-Aranda, A., Luciano, J. V., Demarzo, M., Mariño, M., Soler, J., 10.1007/s12671-019-01241-4 et al. (2021). Psychometric properties of the 15-item five facet mindfulness questionnaire Baer, R. (2019). Assessment of mindfulness by self-report. Curr. Opin. Psychol. 28, in a large sample of Spanish pilgrims. Mindfulness 12, 852–862. doi: 10.1007/ 42–48. doi: 10.1016/j.copsyc.2018.10.015 s12671-020-01549-6 Baer, R. A., Smith, G. T., Hopkins, J., Krietemeyer, J., and Toney, L. (2006). Using self- Feliu-Soler, A., Soler, J., Luciano, J. V., Cebolla, A., Elices, M., Demarzo, M., et al. report assessment methods to explore facets of mindfulness. Assessment 13, 27–45. doi: (2016). Psychometric properties of the Spanish version of the nonattachment scale 10.1177/1073191105283504 (NAS) and its relationship with mindfulness, decentering, and mental health. Mindfulness 7, 1156–1169. doi: 10.1007/s12671-016-0558-0 Bishop, S. R., Lau, M., Shapiro, S., Carlson, L., Anderson, N. D., Carmody, J., et al. (2004). Mindfulness: a proposed operational definition. Clin. Psychol. Sci. Pract. 11, Flora, D. B. (2020). Your coefficient alpha is probably wrong, but which coefficient 230–241. doi: 10.1093/clipsy.bph077 omega is right? A tutorial on using R to obtain better reliability estimates. Adv. Methods Pract. Psychol. Sci. 3, 484–501. doi: 10.1177/2515245920951747 Brown, T. A. (2015). Confirmatory factor analysis for applied research (2nd). New York, NY: Guilford Press. Franquesa, A., Cebolla, A., García-Campayo, J., Demarzo, M., Elices, M., Pascual, J. C., et al. (2017). Meditation practice is associated with a values-oriented life: the mediating role Brown, K. W., and Ryan, R. M. (2003). The benefits of being present: mindfulness and of decentering and mindfulness. Mindfulness 8, 1259–1268. doi: 10.1007/s12671- its role in psychological well-being. J. Pers. Soc. Psychol. 84, 822–848. doi: 017-0702-5 10.1037/0022-3514.84.4.822 Fresco, D. M., Moore, M. T., van Dulmen, M. H., Segal, Z. V., Ma, S. H., Teasdale, J. D., Brunner, M., Nagy, G., and Wilhelm, O. (2012). A tutorial on hierarchically structured et al. (2007). Initial psychometric properties of the experiences questionnaire: validation constructs. J. Pers. 80, 796–846. doi: 10.1111/j.1467-6494.2011.00749.x of a self-report measure of decentering. Behav. Ther. 38, 234–246. doi: 10.1016/j. Cebolla, A., Garcia-Palacios, A., Soler, J., Guillén, V., Baños, R., and Botella, C. (2012). beth.2006.08.003 Psychometric properties of the Spanish validation of the five facets of mindfulness Gilbert, P., Baldwin, M. W., Irons, C., Baccus, J. R., and Palmer, M. (2006). Self- questionnaire (FFMQ). Eur J Psychiatry 26, 118–126. doi: 10.4321/S0213-61632012000200005 criticism and self-warmth: an imagery study exploring their relation to depression. J. Cohen, J. W. (1988). Statistical power analysis for the behavioral sciences (2nd). Cogn. Psychother. 20, 183–200. doi: 10.1891/jcop.20.2.183 Hillsdale, NJ: Lawrence Erlbaum Associates. Gu, J., Strauss, C., Crane, C., Barnhofer, T., Karl, A., Cavanagh, K., et al. (2016). Cuesta-Vargas, A. I., Neblett, R., Chiarotto, A., Kregel, J., Nijs, J., van Wilgen, C. P., Examining the factor structure of the 39-item and 15-item versions of the five facet et al. (2018). Dimensionality and reliability of the central sensitization inventory in a mindfulness questionnaire before and after mindfulness-based cognitive therapy for pooled multicountry sample. J. Pain 19, 317–329. doi: 10.1016/j.jpain.2017.11.006 people with recurrent depression. Psychol. Assess. 28, 791–802. doi: 10.1037/pas0000263 Cuesta-Vargas, A. I., Neblett, R., Nijs, J., Chiarotto, A., Kregel, J., van Wilgen, C. P., Hair, J. F., Anderson, R. E., Tatham, R. L., and Black, W. C. (1998). Multivariate data et al. (2020). Establishing central sensitization-related symptom severity subgroups: a analysis (5th ed.). Upper Saddle River, NJ: Prentice Hall. multicountry study using the central sensitization inventory. Pain Med. 21, 2430–2440. Hancock, G. R., and Mueller, R. O. (2001). “Rethinking construct reliability within doi: 10.1093/pm/pnaa210 latent variable systems” in Structural equation modeling: Present and future—A Festschrift Davidson, R. J. (2010). Empirical explorations of mindfulness: conceptual and in honor of Karl Joreskog. eds. R. Cudeck, S. du Toit and D. Sorbom (Lincolnwood, IL: methodological conundrums. Emotion 10, 8–11. doi: 10.1037/a0018480 Scientific Software International), 195–216. Frontiers in Psychology 13 frontiersin.org Navarrete et al. 10.3389/fpsyg.2023.1212036 Henry, J. D., and Crawford, J. R. (2005). The short-form version of the depression Attacking & Self-Reassuring Scale (FSCRS-SF) in Spanish sample. PLoS One anxiety stress scales (DASS-21): construct validity and normative data in a large non- 16:e0252089. doi: 10.1371/journal.pone.0252089 clinical sample. Br. J. Clin. Psychol. 44, 227–239. doi: 10.1348/014466505X29657 Navarrete, J., Martínez-Sanchis, M., Bellosta-Batalla, M., Baños, R., Cebolla, A., and Hervás, G., Cebolla, A., and Soler, J. (2016). Intervenciones psicológicas basadas en Herrero, R. (2021a). Compassionate embodied virtual experience increases the mindfulness y sus beneficios: estado actual de la cuestión [mindfulness-based adherence to meditation practice. Appl. Sci. 11:1276. doi: 10.3390/app11031276 psychological interventions and benefits: state of the art]. Clínica y Salud 27, 115–124. Ortet, G., Pinazo, D., Walker, D., Gallego, S., Mezquita, L., and Ibáñez, M. I. (2020). doi: 10.1016/j.clysa.2016.09.002 Personality and nonjudging make you happier: contribution of the five-factor model, Hu, L. T., and Bentler, P. M. (1999). Cutoff criteria for fit indexes in covariance mindfulness facets and a mindfulness intervention to subjective well-being. PLoS One structure analysis: conventional criteria versus new alternatives. Struct. Equ. Model. 15:e0228655. doi: 10.1371/journal.pone.0228655 Multidiscip. J. 6, 1–55. doi: 10.1080/10705519909540118 Podsakoff, P. M., MacKenzie, S. B., Lee, J.-Y., and Podsakoff, N. P. (2003). Common Ireland, M. J., Day, J. J., and Clough, B. A. (2019). Exploring scale validity and method biases in behavioral research: a critical review of the literature and recommended measurement invariance of the Toronto mindfulness scale across levels of meditation remedies. J. Appl. Psychol. 88, 879–903. doi: 10.1037/0021-9010.88.5.879 experience and proficiency. J. Clin. Psychol. 75, 445–461. doi: 10.1002/jclp.22709 Reise, S. P., Bonifay, W. E., and Haviland, M. G. (2013). Scoring and modeling Kabat-Zinn, J. (1990). Full catastrophe living: Using the wisdom of your mind and body psychological measures in the presence of multidimensionality. J. Pers. Assess. 95, to face stress, pain, and illness. New York, NY: Delacorte. 129–140. doi: 10.1080/00223891.2012.725437 Kiken, L. G., Garland, E. L., Bluth, K., Palsson, O. S., and Gaylord, S. A. (2015). From Rodriguez, A., Reise, S. P., and Haviland, M. G. (2016). Applying bifactor statistical a state to a trait: trajectories of state mindfulness in meditation during intervention indices in the evaluation of psychological measures. J. Pers. Assess. 98, 223–237. doi: predict changes in trait mindfulness. Personal. Individ. Differ. 81, 41–46. doi: 10.1016/j. 10.1080/00223891.2015.1089249 paid.2014.12.044 Ruimi, L., Hadash, Y., Tanay, G., and Bernstein, A. (2022). “State Mindfulness Scale Kline, R. B. (2015). Principles and practice of structural equation modeling. New York, (SMS)” in Handbook of Assessment in Mindfulness Research. eds. O. N. Medvedev, C. U. NY: Guilford publications. Krägeloh, R. J. Siegert and N. N. Singh. Cham: Springer. Lau, M. A., Bishop, S. R., Segal, Z. V., Buis, T., Anderson, N. D., Carlson, L., et al. Sahdra, B. K., Shaver, P. R., and Brown, K. W. (2010). A scale to measure (2006). The Toronto mindfulness scale: development and validation. J. Clin. Psychol. 62, nonattachment: a Buddhist complement to Western research on attachment and 1445–1467. doi: 10.1002/jclp.20326 adaptive functioning. J. Pers. Assess. 92, 116–127. doi: 10.1080/00223890903425960 Lecuona, O., García-Garzón, E., García-Rubio, C., and Rodríguez-Carvajal, R. Sandín, B., Chorot, P., Lostao, L., Joiner, T. E., Santed, M. A., and Valiente, R. M. (2020). A psychometric review and conceptual replication study of the five facets (1999). Escalas PANAS de afecto positivo y negativo: validación factorial y convergencia mindfulness questionnaire latent structure. Assessment 27, 859–872. doi: transcultural. Psicothema 11, 37–51. 10.1177/1073191119873718 Schermelleh-Engel, K., Moosbrugger, H., and Müller, H. (2003). Evaluating the fit of Lee, W. K., Cho, Y. R., and Kim, S. H. (2010). The study of reliability and validity of structural equation models: tests of significance and descriptive goodness-of-fit the Korean version of the Toronto mindfulness scale. J. Korean Neuropsychiatr. Assoc. measures. Methods Psychol. Res. Online 8, 23–74. 49, 226–234. Siegling, A. B., and Petrides, K. V. (2014). Measures of trait mindfulness: convergent Li, C.-H. (2016). Confirmatory factor analysis with ordinal data: comparing robust validity, shared dimensionality, and linkages to the five-factor model. Front. Psychol. maximum likelihood and diagonally weighted least squares. Behav. Res. Methods 48, 5:1164. doi: 10.3389/fpsyg.2014.01164 936–949. doi: 10.3758/s13428-015-0619-7 Soler, J., Franquesa, A., Feliu-Soler, A., Cebolla, A., García-Campayo, J., Tejedor, R., Luciano, J. V., Barrada, J. R., Aguado, J., Osma, J., and García-Campayo, J. (2014). et al. (2014). Assessing decentering: validation, psychometric properties, and clinical Bifactor analysis and construct validity of the HADS: a cross-sectional and longitudinal usefulness of the experiences questionnaire in a Spanish sample. Behav. Ther. 45, study in fibromyalgia patients. Psychol. Assess. 26, 395–406. doi: 10.1037/a0035284 863–871. doi: 10.1016/j.beth.2014.05.004 Montero-Marin, J., Puebla-Guedea, M., Herrera-Mercadal, P., Cebolla, A., Soler, J., Sommers-Spijkerman, M., Trompetter, H., Ten Klooster, P., Schreurs, K., Gilbert, P., Demarzo, M., et al. (2016). Psychological effects of a 1-month meditation retreat on and Bohlmeijer, E. (2018). Development and validation of the forms of self-criticizing/ experienced meditators: the role of non-attachment. Front. Psychol. 7:1935. doi: 10.3389/ attacking and self-reassuring scale—short form. Psychol. Assess. 30, 729–743. doi: fpsyg.2016.01935 10.1037/pas0000514 Naismith, I., Mwale, A., and Feigenbaum, J. (2018). Inhibitors and facilitators of Tanay, G., and Bernstein, A. (2013). State mindfulness scale (SMS): development and compassion-focused imagery in personality disorder. Clin. Psychol. Psychother. 25, initial validation. Psychol. Assess. 25, 1286–1299. doi: 10.1037/a0034044 283–291. doi: 10.1002/cpp.2161 Thompson, E. R. (2007). Development and validation of an internationally reliable short-form of the positive and negative affect schedule (PANAS). J. Cross-Cult. Psychol. Navarrete, J., Campos, D., Diego-Pedro, R., González-Hernández, E., Herrero, R., 38, 227–242. doi: 10.1177/0022022106297301 Baños, R. M., et al. (2021b). Compassion-based meditation quality practice and its impact on the positive attitudes toward others. Mindfulness 12, 1940–1953. doi: 10.1007/ Vandenberg, R. J., and Lance, C. E. (2000). A review and synthesis of the measurement s12671-021-01652-2 invariance literature: suggestions, practices, and recommendations for organizational research. Organ. Res. Methods 3, 4–70. doi: 10.1177/109442810031002 Navarrete, J., García-Salvador, M. Á., Cebolla, A., and Baños, R. (2022). Impact of mindfulness training on Spanish police officers’ mental and emotional health: a Yu, S., Rodriguez, M. A., Deng, Y., Xiao, L., and Liu, X. (2021). The Toronto non-randomized pilot study. Mindfulness 13, 695–711. doi: 10.1007/ mindfulness scale: psychometric properties of the Chinese version. Mindfulness 12, s12671-022-01827-5 1976–1984. doi: 10.1007/s12671-021-01655-z Navarrete, J., Herrero, R., Soler, J., Domínguez-Clavé, E., Baños, R., and Cebolla, A. Zuckerman, M. (1983). The distinction between trait and state scales is not arbitrary: (2021c). Assessing self-criticism and self-reassurance: examining psychometric comment on Allen and Potkay's "on the arbitrary distinction between traits and states.". properties and clinical usefulness of the short-form of the forms of self-criticizing/ J. Pers. Soc. Psychol. 44, 1083–1086. doi: 10.1037/0022-3514.44.5.1083 Frontiers in Psychology 14 frontiersin.org