Borderline personality disorder (BPD) is a psychological disorder characterized by pervasive patterns of dysregulation in affective, interpersonal, behavioral, and cognitive domains. BPD affects approximately 0.5%  to 5.9%  of the general population, and is known as a disorder associated with elevated suicidal risks and significant psychosocial impairment [3, 4].
One influential model of BPD’s etiology is Linehan’s biosocial model . The biosocial model posits that symptoms of BPD are a reflection of difficulties with emotion regulation (or emotion dysregulation). This emotional dysregulation evolves out of an on-going, transactional relationship between pre-existing emotional vulnerability and an invalidating childhood environment. Emotional vulnerability refers to the individual’s biological predisposition for unstable and intense negative affect, with high sensitivity to emotions and a slow return to baseline emotionality. An invalidating environment, on the other hand, refers to an environment that persistently disregards, ignores, or punishes an individual for expressing his or her needs and emotions. Examples of forms of invalidation include physical, sexual and emotional abuse, pervasive criticizing, minimizing, trivializing and punishing of the individual, and routine pathologizing of the individual as possessing socially undesirable personality traits [6, 7]. Invalidation may also occur in ways that are more subtle, for example, via intolerance of expression of emotional experience or oversimplifying problem solving when the child is not capable of accomplishing a particular task. Experiences of invalidation may result in individuals internalizing such behaviors (e.g., engaging in self-invalidation) and failing to learn adaptive ways of regulating emotions. As a result, individuals may resort to maladaptive ways of coping with negative emotions, such as recurrent self-injurious behaviors, which is a common feature of BPD.
To date, the role of invalidation in the etiology of BPD has received some empirical support. The majority of these studies were conducted in Western contexts such as Europe, North America, or Australia. In a sample of 202 college students based in the U.S., Cheavens and colleagues found that perceived parental criticism (a form of invalidation) was positively associated with BPD features, and this relationship was partially mediated by thought suppression (a maladaptive emotion regulation strategy) . Another cross-sectional study by Sturrock and colleagues found support for a multiple mediational model, in which poor distress tolerance (a facet of emotional vulnerability) and emotional regulation difficulties mediated the association between invalidation and BPD symptoms .
Further, there is emerging work suggesting that the effects of invalidation on BPD symptoms may vary by parent’s gender. Previous research has highlighted the relative importance of the mother (versus the father) as the primary caregiver  in contributing to an environment of invalidation and the subsequent development of BPD [11, 12]. For example, a study by Sturrock and colleagues found that maternal invalidation, as opposed to paternal invalidation, significantly predicted BPD symptoms in a nonclinical sample . In another study, it was found that BPD symptoms were associated with maternal overprotection (e.g., invasion of privacy), but not paternal overprotection . Meanwhile, in a large sample of female undergraduates, Reeves and colleagues found no association between parental invalidation and BPD symptoms . It remains to be examined whether the association between parental invalidation and BPD symptoms would emerge more consistently, should the constructs of maternal versus paternal invalidation be assessed separately.
While selected findings allude to the idea that maternal invalidation may result in more adverse consequences compared to paternal invalidation, existing literature on parent-child relationships highlight an increasingly complex ecological context where both mothers and fathers exert influence over children’s development [14,15,16]. For example, it has been argued that father’s parenting behaviors affect children’s outcomes in ways that are similar to mother’s parenting behaviors . In a study by McDowell and Parke, both mothers’ and fathers’ parental behaviors (e.g., advice-giving and support) predicted children’s social competence and social acceptance from peers one year later . It remains to be investigated whether the parent’s gender may differentially influence specific domains of children’s development, such as emotion regulation, which is known as a core deficit in the presentation of BPD .
Invalidation and BPD in the Asian context
As highlighted above, empirical support for the biosocial model derives mainly from studies conducted in Western samples. Research has shown that the presentation and etiology of psychopathology varies by culture . Little work to date has examined the etiology and correlates of BPD in the Asian context. Huang and colleagues recruited a sample of 400 Chinese adults and found that compared to individuals with other personality disorders and those without personality disorders, those who received a BPD diagnosis reported higher levels of parental physical, emotional, and sexual abuse . In a separate study involving Chinese outpatients, Zhang and colleagues found that BPD symptomatology correlated positively 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 broader construct of childhood invalidation in relation to BPD symptomatology. Further, given the heterogeneity of cultures within Asia, these findings may not be generalizable to the Southeast Asian context . To date, no study has yet examined the role of parental invalidation in the development of BPD symptoms in a Singaporean context – a multicultural society influenced by Confucius values, as well as other Southeast Asian heritages such as Malay and Indian cultures . In Singapore, it has been found that mothers tend to be the primary caregivers, although the disciplining of children is often shared by fathers as well . Further, a longitudinal study showed that maternal warmth (versus paternal warmth) uniquely predicts emotional adjustment among children in China, a country that shares cultural similarities with Singapore . Taken together, the findings suggest that invalidation from the mother (versus paternal invalidation) may have a stronger impact on the development of emotional dysregulation and BPD symptoms. Therefore, we predicted that relative to paternal invalidation, maternal invalidation would be more strongly associated with BPD symptoms in Singapore.
Exploring the role of cultural factors in the etiology of BPD
Culture can be broadly defined as a set of psychosocial processes that differentiate one group from another, which include rituals, customs, institutions, beliefs and values . Given existing research that has demonstrated the complex influence of culture on cognition , affect , behavior , and how mental disorders develop and are expressed , it is plausible that specific cultural variables may be implicated in the etiology of BPD. Two cultural variables of interest are self-construal and conformity.
Several studies have investigated the role of self-construal in relation to mental health outcomes such as depression and anxiety [30, 31], but little work has explored the potential relevance of self-construal for understanding the etiology of BPD symptoms. Self-construal is a dimension of culture that pertains to the extent to which individuals understand the self as a unique, separate entity (independent self-construal), or as being defined by important, close relationships to others (interdependent self-construal) [32, 33]. Individuals with an independent self-construal tend to define themselves by their own, unique set of internal attributes (e.g., values, motives, goals), while those with an interdependent orientation tend to perceive themselves in reference to others’ feelings, thoughts, and wishes . These two forms of self-construal parallel broader cultural dimensions of Individualism versus Collectivism. Whereas individualistic societies emphasize values related to autonomy, freedom, and personal traits and preferences, collectivistic societies prioritize values such as conformity to norms and emotional control in service of culturally important goals such as social harmony, smooth interpersonal functioning, and duty to one’s ingroups [35, 36].
It is notable, however, that an individual’s self-construal may not always correspond to the prevailing culture’s position on the Individualism-Collectivism dimension . Endorsing a particular self-construal orientation does not automatically imply that one would subscribe to values that are typically associated with the larger cultural context. For example, it is possible that an individual living in a largely collectivist society endorses interdependent self-construal, and yet does not value conformity highly. Therefore, endorsement of self-construal and the extent to which one values conformity are related yet dissociable constructs. In this study, we define conformity as the tendency to conform to family and social norms and expectations, a trait conceptualized to be an important dimension of Asian values .
As highlighted above, early experience of invalidation has been theorized as an important etiological factor in BPD . Beyond the objective act or behavior reflective of invalidation, the way through which an act of invalidation is perceived or interpreted may serve to exacerbate or buffer the negative impact of invalidation on emotion dysregulation and related BPD symptoms. We propose that self-construal and conformity are two factors that influence how individuals perceive, or respond to experiences of invalidation. With regards to conformity, we postulate that individuals who value conformity to norms may be more adversely affected by experiences of childhood invalidation, compared to those who do not value conformity as highly. Such individuals may experience the interpersonal obligations to conform more strongly, and perceive experiences of invalidation as a personal failure to fulfill those obligations. As a result, they may be more vulnerable to experiencing dysregulation and related BPD symptoms resulting from early experiences of invalidation. This is particularly so as parents, or primary caregivers, are the main agents of norm socialization in childhood . Conversely, individuals who do not value conformity highly may not be as adversely affected by experiences of invalidation, as the perceived obligation to conform or adhere to others’ expectations may not be as strong. In the face of similar experience or history of invalidation, individuals who endorse high levels of conformity may therefore demonstrate greater symptoms of BPD, compared to those who endorse low levels of conformity. In fact, existing literature shows that a high level of family conformity orientation (the extent to which parents impose the value of conformity in children) is positively related to depression and conversely related to self-esteem in young adults and children respectively, suggesting that conformity may be a risk factor in the development of mental health issues [39, 40]. No research however has yet examined the role of conformity (as endorsed by the individual) in relation to experiences of invalidation and BPD symptoms.
As self-construal exerts a pervasive influence on how an individual relates to the self and the world , the effect of conformity on the association between invalidation and BPD symptoms may vary as a function of an individual’s self-construal. An individual who possesses a largely independent self-construal is less likely to value interpersonal obligations towards others strongly , which, in a way, may protect them from the negative impact of invalidation. For these individuals, the extent to which conformity is valued may have less of a bearing on how experiences of invalidation impact them. However, arguably, adopting a predominantly independent self-construal in a largely collectivist society (e.g. Singapore)  may render an individual vulnerable to experiences of invalidation, due to the inconsistency between his/her own values and the society’s values, as suggested by prior research demonstrating that a lack of fit between one’s personality and a society’s values predisposes one to having poor mental health . Therefore, it is an exploratory question how experiences of invalidation would be associated with BPD symptoms for individuals with an independent self-construal.
In contrast, the association between invalidation and BPD symptoms for individuals with an interdependent self-construal may vary more as a function of conformity. An individual characterized by interdependent self-construal is likely to deem interpersonal obligations as important , which may predispose them to being vulnerable to experiences of invalidation and related symptoms of BPD, especially if they also value conformity to norms highly. Meanwhile, those who do not value conformity as highly may be less negatively impacted by experiences of invalidation. For these individuals, adopting an interdependent self-construal may even serve as a protective mental health factor in a society that values collectivism . Therefore, it is plausible that conformity and self-construal may exert an interactive effect on the relationship between childhood invalidation and BPD symptoms. A comprehensive examination of the association among conformity, invalidation, and symptoms of BPD needs to take into account self-construal as a factor that may enhance or diminish the impact of conformity on the relationship between invalidation and BPD symptoms.
Within the larger literature, research has demonstrated a positive association between an interdependent self-construal and psychological symptoms, suggesting that individuals who are more focused on meeting duties, obligations, and social responsibilities associated with the group to which they belong (versus asserting their autonomy, needs, and wishes) may be more at risk for developing mental distress generally [43, 44]. We postulate that one way through which interdependent self-construal affects the development of mental distress may be via its influence on individuals’ responses to experiences of invalidation from the group (e.g., parents). To date, no research has yet examined type of self-construal as a potential moderator of the association between perceived invalidation and BPD symptoms.
Specific aims and hypotheses
The present study aimed to investigate the association between parental invalidation and BPD symptoms in the Singaporean context, as well as explore the role of self-construal and conformity as potential moderators of the association. Following Reeves and colleagues , we adopted a dimensional perspective of BPD symptoms and recruited a nonclinical sample of college students, as late adolescence and young adulthood represents a developmental period whereby the symptoms of BPD tend to peak . Based on previous research, it was hypothesized that maternal invalidation would be more strongly and positively correlated with BPD symptoms, as compared to paternal invalidation. We further hypothesized that the association between invalidation and BPD symptoms would be moderated by the interaction between self-reported degree of conformity to norms and self-construal. Specifically, we predicted that the association between invalidation and BPD symptoms would be stronger at high levels of conformity (versus low levels of conformity) among individuals with an interdependent self-construal. It was an exploratory question the extent to which invalidation would be associated with BPD symptoms, and whether the association would be moderated by conformity, among individuals with an independent self-construal.