Borderline personality disorder (BPD) is a severe condition characterized by dysregulated affect, cognition, behaviors, and interpersonal relationships . Several symptoms of BPD include fear of abandonment, unstable and intense relationships characterized by fluctuations between idealization and devaluation of others, difficulty controlling anger, and chronic feelings of emptiness. BPD is known as one of the most challenging disorders to treat, in part due to the high prevalence of nonsuicidal self-injury and suicide attempts in this population [2, 3]. While there are several developmental models of BPD [4, 5], one of the most dominant models is Linehan’s biosocial theory of BPD . According to the biosocial model, BPD is characterized by marked emotion dysregulation, which arises from a transactional relationship between pre-existing emotional vulnerability (characterized by emotional sensitivity, reactivity, and slow return to baseline) and an invalidating childhood environment. Invalidation may occur in a variety of forms; broadly speaking however, an invalidating environment is one in which a child’s inner experience and expression of emotions, thoughts, and behaviors are frequently criticized, trivialized, ignored, and/or punished. In support of the biosocial theory, various studies have demonstrated an association between childhood invalidation and development of BPD symptoms. Compared to both clinical and non-clinical controls, there is a higher incidence of reported childhood psychological abuse, physical abuse, and neglect among BPD patients [7,8,9]. Besides severe forms of invalidation such as childhood maltreatment, studies also suggest that parental contradictory communication patterns , absence of maternal protection , and parental overprotection without affection  as perceived by individuals with BPD were associated with the development of BPD pathology. Most of the existing studies were conducted in North American or European settings, which limit the generalizability of their findings to other cultural contexts, such as Asia.
BPD in Asia
Few studies to date have examined components of the biosocial theory in Asia. Huang et al.  recruited a sample of 400 Chinese participants, and found that compared to individuals with other personality disorders and those without personality disorders, individuals who received a BPD diagnosis reported higher levels of parental physical, emotional, and sexual abuse. In another study, Zhang et al.  examined a sample of 1402 Chinese patients from an outpatient counselling center, and found that BPD symptomatology was positive associated with childhood emotional, physical and sexual abuse, as well as childhood emotional and physical neglect. While these findings provide some support for the biosocial model, none of the studies specifically assessed the construct of childhood invalidation in relation to BPD symptomatology. Further, the fact that Asian cultures tend to emphasize interdependence, emotion control, and hierarchy [15, 16] might imply a high level of invalidation experienced at the individual and/or collective level. While the present study was not set up to provide direct comparison between cross-cultural samples, we aimed to provide a preliminary investigation of the association between childhood invalidation and BPD symptoms in the Singaporean context – a multicultural Asian society influenced by Confucius values as well as other Southeast Asian heritages such as Malay and Indian cultures .
Self-compassion and BPD
Beyond the issue of cross-cultural applicability of the biosocial model, it is important to examine factors that may moderate the association between childhood invalidation and BPD symptomatology. Several factors that have received research attention include affective dysfunction and social support. In one study, affective dysfunction was found to moderate the association between emotional abuse and childhood BPD symptoms, with emotional abuse predicting BPD features only among children with high (versus low) affective dysfunction . Consistent with this study, research has demonstrated that Tryptophan Hydroxylase I (TPH-1) gene – a gene implicated in the serotonergic stress response pathway- moderated the association between childhood abuse and diagnosis of BPD . Another study examined whether social support would moderate the association between childhood sexual abuse and borderline personality features, but did not find support for the moderation effect . Beyond these studies, little work has investigated whether adaptive personality traits may influence the association between invalidation and BPD symptoms. In this study, we were interested in examining self-compassion as a potential correlate of BPD symptoms, as well as moderator of the association between childhood invalidation and BPD symptoms.
A construct originating from Buddhist teachings, self-compassion refers to the tendency to be moved by one’s suffering, such that one yearns to reduce one’s suffering and to treat oneself with kindness and empathy [21, 22]. Neff [21, 22] conceptualizes self-compassion as consisting of three aspects: 1) self-kindness, referring to the ability to relate to oneself kindly; 2) common humanity, which refers to the acknowledgement that setbacks and imperfection are inevitable among all human beings, as opposed to feeling isolated during times of failure; and 3) mindfulness, which refers to being accepting and aware of both negative and positive experiences, as opposed to over-identifying with one’s inner experiences. Depending on context, self-compassion can be conceptualized as a personality trait, referring to the general tendency of an individual to adopt an attitude of compassion towards him- or herself in everyday life [21, 22], a momentary state of being kind to oneself , or a strategy of coping with difficult experiences (e.g., intentionally extending wishes of loving-kindness towards oneself when encountering an experience of failure ).
As a personality trait, self-compassion has been associated with reduced symptoms of depression and anxiety across multiple contexts, ranging from academic to interpersonal domains [21, 23, 25]. Self-compassion has also been found to correlate with greater well-being in both adolescents and older adults [26, 27]. Among clinical populations, depressed patients have been found to demonstrate lower levels of self-compassion compared to non-depressed individuals, even after controlling for depressive symptoms . Further, the association between self-compassion and depressive symptoms was mediated by shame, symptom-focused rumination, and cognitive and behavioral avoidance [28, 29]. In one study, a brief self-compassion manipulation resulted in decreases in shame and negative affect compared to a control condition . These findings are consistent with the idea that self-compassion serves as a direct antidote to shame , which has been proposed to be a core emotion underlying BPD . A meta-analysis found a large effect size (r = .54) for the relationship between self-compassion and psychopathological symptoms, particularly depression, anxiety, and stress . Taken together, the findings suggest a strong relationship between self-compassion and psychological health, and point to the role of self-compassion in reducing maladaptive, transdiagnostic emotional and cognitive processes, such as shame, rumination, and avoidance. Little work however has directly examined the association between self-compassion and symptoms of BPD. Given that BPD is characterized by similar maladaptive cognitive processes that have been found to be impacted by self-compassion [31, 33], we predicted that self-compassion would be negatively correlated with BPD symptoms.
Further, there is evidence indicating that self-compassion may moderate, or attenuate emotional reactions to adverse events. For example, Leary et al.  found that individuals with high self-compassion showed less negative behavioral and emotional reactions when imagining distressing events, compared with less self-compassionate individuals. Further, people with greater self-compassion demonstrate the ability to acknowledge their role in negative situations without feeling overwhelmed by negative emotions . In another study, self-compassion, relative to self-esteem, predicted greater decreases in anxiety after participants were exposed to an ego-threat (i.e., thinking about their greatest weakness) in a laboratory setting . Among patients with major depressive disorder, a brief self-compassion manipulation was found to be more effective than reappraisal in downregulating depressed mood, particularly at high levels of baseline depressed mood . Overall, these findings highlight the potential role of self-compassion in moderating individuals’ reactions to experiences of invalidation. In the context of BPD, adopting a self-compassionate perspective may help lower one’s tendency to internalize feelings of shame, or self-invalidation that that may result from repeated experiences of invalidation .
Further, there is evidence that self-compassion is associated with use of more adaptive emotion regulation styles. For example, self-compassion was found to predict greater emotional processing, as well as lower rumination, thought suppression, and catastrophizing across both cross-sectional and laboratory studies [22, 23]. The common humanity facet of self-compassion may also support the ability to reframe distressing life circumstances as part of what all humans experience . Considering the role of self-compassion in moderating reactions to aversive events and promoting adaptive emotion regulation, it is plausible that high levels of self-compassion may predict a weaker association between experiences of invalidation and development of BPD symptoms. To date, no study has yet examined whether trait self-compassion may moderate the relationship between childhood invalidation and BPD symptoms.
The present study
The present study aimed to examine the association among self-compassion, childhood invalidating environment, and BPD symptoms in a sample of Singaporean undergraduate students. Based on previous research, it was hypothesized that an invalidating childhood environment would be positively correlated with BPD symptomatology. It was also hypothesized that self-compassion would be inversely correlated with BPD symptomatology. We further predicted that self-compassion would moderate the relationship between an invalidating childhood environment and BPD symptomatology. Specifically, the relationship between an invalidating childhood environment and BPD symptomatology was expected to be weaker among those with higher levels of self-compassion, and vice versa among those with lower levels of self-compassion. In this study, we adopted a dimensional perspective of BPD symptoms and recruited on a nonclinical sample of college students, as young adulthood represents a developmental period whereby the symptoms of BPD tend to begin to emerge .