Childhood maltreatment is linked to larger preferred interpersonal distances towards friends and strangers across the globe

Childhood maltreatment (CM), encompassing abuse and neglect, is a widespread global issue with prevalence rates varying significantly across gender and continents. The consequences of CM are substantial, increasing the risk of mental and physical health disorders. Furthermore, CM is strongly linked to social dysfunction, including isolation, withdrawal, victimization, and peer rejection. It's associated with low social support, relationship problems, and increased loneliness and social isolation. Research suggests that CM may underlie these social difficulties by altering responses to social stimuli. Adults with CM demonstrate differences in recognizing facial expressions, tending to perceive neutral expressions as negative. They often show discomfort and heightened neural reactivity to social touch. Enhanced amygdala responses to negative facial expressions and hyperreactivity to unfamiliar faces have also been observed. These responses are consistent with the heightened threat sensitivity often seen in individuals exposed to CM, leading to negative reactions to various social stimuli. Interpersonal distance, the preferred physical space maintained during social interactions, is a crucial factor potentially impacted by CM. Comfortable interpersonal distance (CID) is usually assessed using the stop-distance paradigm, where participants indicate when an approaching person's proximity becomes uncomfortable. CID develops during childhood and is influenced by several factors, including the relationship with the approaching person, age, gender, culture, and geographic factors such as temperature and population density. Existing research suggests a correlation between CM and increased CID, particularly in physically abused children and adults experiencing various forms of CM. However, this research is limited by small sample sizes, primarily focusing on European populations and only considering CID towards strangers. The current study aims to address these limitations by investigating the association between CM and CID in a large, multinational sample, exploring differences in CID toward friends versus strangers, and examining the relationship between CID, social functioning, and attachment.

Existing literature demonstrates a clear association between childhood maltreatment and various forms of social dysfunction. Studies highlight difficulties in emotion recognition, particularly regarding positive emotions, and a bias towards interpreting neutral expressions as negative. Increased neural reactivity to social touch and negative facial expressions are also documented. These findings point towards an altered processing of social stimuli among individuals who experienced CM. Research on interpersonal distance reveals that comfortable interpersonal distance (CID) varies across cultures and is influenced by factors such as relationship type, age, gender, and environmental conditions. Previous research on the link between CM and CID, using the stop-distance paradigm, has shown increased CID in physically abused children and adults with various forms of CM, however, these studies were limited by small sample sizes and primarily focused on European participants. The limited number of studies and their geographical restrictions hinder the generalizability of findings.

This study employed a large multinational sample (N=2986) recruited through diverse channels, including personal contacts, online platforms, and social media advertisements. Participants were adults aged 18 and older with sufficient reading skills in the local language. Several exclusion criteria were applied, such as incomplete trials in the CID task or excessive variance in reaction times during control trials. The final sample included 2986 participants (69.2% female, mean age 31.27). Data was collected online between October 2021 and March 2022 using Qualtrics software. The primary dependent variable was comfortable interpersonal distance (CID), measured using a modified online version of a validated CID task. In this virtual task, participants imagined themselves as a figure in a circular room and observed another figure (either a friend or a stranger) approaching. They pressed a spacebar when the approaching figure's proximity became uncomfortable. Reaction times were recorded, with longer times indicating smaller CID. Several questionnaires were administered to assess childhood trauma (Childhood Trauma Questionnaire; CTQ), lifetime trauma exposure (Life Events Checklist; LEC), PTSD symptoms (International Trauma Questionnaire; ITQ), social anxiety (Mini-Social Phobia Inventory; MINI-SPIN), depression (Patient Health Questionnaire-9; PHQ-9), social support (Multidimensional Scale of Perceived Social Support; MSPSS), interpersonal stress (Bergen Social Relationships Scale; BSRS), attachment styles (Experiences in Close Relationships Scale - Short Form; ECR-S), and fear of COVID-19 (Fear of the Coronavirus Questionnaire; FCQ). Data analysis involved multilevel modeling to account for the nested structure of the data (trials within participants within countries). For hypotheses examining the link between CM, CID, and the approaching individual (stranger vs friend), models included CM scores, the type of approaching individual, their interaction, and relevant covariates. Separate analyses were conducted for each subtype of CM, and models were tested to identify the best fit. For hypotheses relating social functioning and CID, a separate multilevel model included measures of attachment styles, social support and interpersonal stress as predictors, along with relevant covariates.

The study found a significant association between higher levels of childhood maltreatment (CM) and larger comfortable interpersonal distances (CID) towards both friends and strangers. This relationship was consistent across various countries and cultures, suggesting a robust association regardless of cultural context. Specifically: * Higher CM scores predicted larger CID towards both friends (β = -0.0082, p < 0.001) and strangers (β = -0.0077, p < 0.001). The interaction between CM and the approaching individual was not significant. * Analyses of CM subscales showed significant effects of physical abuse, sexual abuse, emotional neglect, and physical neglect on CID. Effects were most pronounced for physical abuse and neglect. * Less social support from significant others (β = 0.22, p < 0.001) was linked to larger CID. However, interpersonal stress was not significantly related to CID. * Insecure attachment styles (both anxious and avoidant) were associated with larger CID. Anxious attachment (β = -0.12, p < 0.001) and avoidant attachment (β = -0.09, p < 0.001) predicted greater CID. * Contrary to expectations, higher social anxiety scores were associated with smaller CID (β = 0.06, p < 0.001).

This study provides strong evidence that childhood maltreatment (CM) is associated with altered comfortable interpersonal distance (CID) across various cultures. The consistent effect of CM on CID, irrespective of the approaching individual (friend or stranger) and across diverse countries, highlights the robustness of this association. This suggests that CM may universally impact mechanisms regulating interpersonal space, possibly involving structures like the amygdala. The finding of larger CID in individuals with insecure attachment further supports the link between CM and impaired social functioning. The relationship between low social support and increased CID underscores the potential impact of CM on interpersonal relationships and the need for interventions focused on improving social functioning. The unexpected finding of smaller CID in individuals with higher social anxiety needs further investigation. This could be due to the nature of the virtual task, possibly creating a sense of safety for those with social anxiety. The study's limitations, such as the virtual nature of the CID task and varying sample sizes across countries, should be considered when interpreting results. Further research is needed to clarify the association of loneliness, social support and CID. Interventions targeting improved social skills and increased feelings of security might be beneficial for individuals impacted by CM.

This large-scale multinational study confirms a robust link between childhood maltreatment and increased comfortable interpersonal distance across diverse cultural contexts. Larger CID is associated with insecure attachment and low social support, highlighting the profound impact of CM on social functioning. Future research should focus on refining methods of measuring CID, exploring longitudinal effects, and investigating interventions that enhance social interaction and improve the regulation of interpersonal space in individuals with a history of CM. The consistent findings across diverse populations suggest the potential for universally applicable therapeutic approaches.

The study's primary limitation is the use of a virtual reality task to assess comfortable interpersonal distance. While this methodology has shown correlation with real-life distances, it might not fully capture the nuances of real-world social interactions. The varying sample sizes across countries could also affect the generalizability of findings. Additionally, the cross-sectional nature of the study limits the ability to infer causal relationships. The assessment of social anxiety with a brief measure may also limit the reliability of these findings. Future studies could benefit from utilizing more ecologically valid methods of assessing CID, incorporating longitudinal data, and utilizing more comprehensive measures of social anxiety.