Attachment theory, with its core concepts, perspectives, and insights developed over the past five decades, is influential for professionals working with young children. However, practitioners face challenges translating attachment theory and research into practical applications. This manifests in attachment myths, theoretical misinterpretations, and inconsistency of application. This state-of-the-art review is authored by 47 attachment researchers and practitioners and examines key insights from attachment theory to facilitate attachment-aware practice for professionals working with children and their caregivers. Following the ongoing debate on practical relevance in attachment theory, we present both 'strict' and 'expansive' translational perspectives on applications for addressing preventative or clinical attachment concerns. We first review core attachment propositions, based on replicated research of attachment and caregiving. We next address common misconceptions that hinder adequate practical applications. We present measures of attachment and sensitive parenting that might be helpful for practitioners. We also review evidence-based and promising attachment interventions, discussing core components of (preventative) support for parents or caregivers and the children in their care. We emphasize that attachment theory's clinical value lies not in assigning attachment classifications, but rather in understanding crucial insights into caregiving and early socioemotional development (e.g., secure base phenomena; the value of safe, stable, and shared good-enough care), developed in attachment research over the past 50 years, that may inform policy and clinical reasoning and areas for prevention and intervention.

Interbrain synchrony (IBS) is thought to reflect the flow of information between individuals and interpersonal mechanisms like empathy and bonding. Previous research suggests that IBS varies according to different factors, including interpersonal bond type, individual characteristics, emotional valence and physical presence/absence. This study investigated how IBS in mother-child dyads varies during imagined emotional situations, focusing on valence and imagined presence/absence of the mother. We used functional near-infrared spectroscopy (fNIRS) hyperscanning to measure IBS over the right prefrontal cortex, dorsolateral prefrontal cortex and temporoparietal junction in 38 mother-child dyads (child age: 10–14 years). Results showed that IBS differed across valence only when participants imagined the mother being present, with higher IBS in negative situations than in positive ones. Furthermore, in scenarios imagined with the mother present, IBS was associated with the mother’s personal distress —negative correlation in positive scenarios, and positive correlation in negative scenarios—and with children’s secure base support scores—negative association in the frontopolar cortex. These findings suggest that mothers and children perceive being together differently, depending on emotional valence, social context and individual differences. Overall, our results suggest that IBS reflects dyadic emotional processing and highlight associations with individual traits in dyadic neural synchrony.

Childhood maltreatment has been linked to biased internal working models that contribute to later social problems. It is unclear, however, how internal working models influence actual peer encounters in real-time. In this preregistered study, N = 133 adolescents and young adults (n = 65 maltreated; 11–24 years) from a longitudinal cohort played Cyberball ostensibly with two peers, both introduced before the game via descriptive statements: The Target peer was constructed to implicitly resemble participant’s one of the parents, and the Control peer resembled someone else’s parent. We recorded event-related cardiac slowing during my-turn (micro-inclusion) and not-my-turn (micro-exclusion) events. We observed differential cardiac responses to the two peers, which further varied by maltreatment status and age. During micro-exclusion, nonmaltreated participants showed greater cardiac slowing to Target, whereas maltreated participants showed greater cardiac slowing to Control, suggesting that participants selectively generalized their expectations. Cardiac slowing to Target was most pronounced in younger participants and diminished with age, suggesting that parental cues exert a stronger influence on peer interactions at younger ages. Together, our findings suggest that cardiac slowing can index rapid processing of representation-based expectations during social interactions and may thus constitute a mechanism by which internal models impact social functioning.

The preschool years are crucial for school readiness, with the child-parent attachment relationship providing a foundational context for skill acquisition as part of this transition. Advances in social neuroscience suggest that interpersonal neural synchrony (INS) represents a valuable index of interaction and relationship quality. We examined whether parent-child INS during a parent-guided learning task was associated with observed parental interaction behavior and narrative child attachment representations. INS in bilateral frontal and temporoparietal cortex was assessed using functional near-infrared spectroscopy (fNIRS) hyperscanning in ninety-three parents (51 fathers) and their biological children (aged 5-6 years, 48 girls) while parents guided children through cognitive exercises. Parental interaction behavior was assessed using video-coded NICHD sensitivity scales, and children’s attachment representations were indexed by narrative coherence using the Picture Story Stem Battery (PSSB). Results revealed specific region-dependent functional patterns. A positive correlation between parental respect for autonomy and quality of assistance with bilateral prefrontal INS possibly reflecting cognitive scaffolding. Furthermore, INS in the left prefrontal cortex positively correlated with child task performance and mediated the relationship between parental assistance and task success. In contrast, temporoparietal INS, particularly in mother-child dyads, possibly reflected relational and regulatory processes. While child attachment security positively correlated with right temporoparietal INS, maternal hostility negatively correlated with bilateral temporoparietal INS. Taken together, our findings suggest that INS in the prefrontal and temporoparietal cortex may serve as a differential neurobiological correlate of dyadic coordination, possibly capturing both the relational quality of the child-parent attachment bond and the efficacy of parental scaffolding in supporting early learning.

Adverse caregiving experiences are thought to bias internal representations of self and others, giving rise to negative expectations that generalize to new encounters. However, few studies examine whether cues signaling resemblance to caregivers selectively increase the odds of generalization. In this preregistered study, 133 participants were assessed for maltreatment at two waves (n = 65 maltreated; ages 4–16 and 11–24 years). At the second wave, participants played Cyberball. Following social exclusion, participants re-engaged with two novel co-players, who ostensibly introduced themselves via self-descriptive blurbs: The Target implicitly resembled the participant’s caregiver, whereas the Control resembled someone else’s caregiver. The co-players threw the ball to participants (re-inclusions) or not (re-exclusions) at equal rates. We assessed event-related cardiac slowing, a correlate of expectancy violation. Cardiac slowing to Target was most pronounced in younger participants and declined with age, suggesting that caregiver cues exert a stronger influence on peer interactions at younger ages. Supporting our pre-registered hypotheses, during re-exclusions, maltreated participants showed greater cardiac slowing to Control vs. Target, whereas nonmaltreated participants exhibited the opposite pattern. We conclude that, for maltreated individuals, re-exclusion violates expectancies less when stemming from caregiver-like targets, implying that resemblance cues trigger selective generalization during early psychophysiological processing.

This cross-sectional study investigated the relationship between depressive symptoms and creative personality through the lens of epigenetic modifications within Hypothalamic-Pituitary-Adrenal (HPA) axis genes. By analyzing DNA methylation patterns in key HPA axis genes-including corticotropin-releasing hormone (CRH), its receptor (CRHR1), CRH binding protein (CRHBP), melanocortin 2 receptor (MC2R), steroidogenic acute regulatory protein (STAR), FK506 binding protein 5 (FKBP5), and the glucocorticoid receptor (NR3C1), we examined how methylation variation was associated with the depressive symptoms-creativity link in 371 participants (190 women, 181 men). Our findings revealed that among individuals with methylation patterns putatively associated with reduced HPA axis activity, higher depressive symptoms were positively associated with creative personality, suggesting that in this biological context, introspective aspects of depressive symptoms may coincide with creative propensities. Conversely, among individuals with methylation patterns putatively associated with heightened HPA axis activity, higher depressive symptoms were negatively associated with creative personality. These results suggest that the association between depressive symptoms and creativity is not uniform but differs based on methylation variation in genes involved in stress response regulation. The findings highlight the potential role of HPA axis-related biological factors in understanding individual differences in the depression-creativity relationship, though the cross-sectional design precludes causal inference.

Abstract Human social interactions rely on the ability to reflect on one’s own and others’ internal states and traits—a process known as mentalizing. Impaired or altered mentalizing is a hallmark of multiple psychiatric and neurodevelopmental conditions. Yet, replicable and easily testable brain markers of mentalizing have so far been lacking. Here, we apply an interpretable machine learning approach to multiple datasets (total n = 390) to train and validate fMRI brain signatures that predict i) mentalizing about the self, ii) mentalizing about another person, and iii) both types of mentalizing. Self-mentalizing and other-mentalizing classifiers had positive weights in anterior/medial and posterior/lateral brain areas, respectively, with accuracy rates of 82% and 77% for out-of-sample prediction. The classifier trained across both types of mentalizing showed 98% predictive accuracy and separated (mental) attributional from factual inferences. Classifier patterns revealed better self/other separation in healthy adults compared to individuals with schizophrenia and with increasing age in adolescence. Together, our findings reveal consistent and separable neural patterns subserving trait-based mentalizing about self and others—present at least from the age of adolescence and functionally altered in severe neuropsychiatric disorders. These mentalizing signatures hold promise as candidate neuromarkers of social-cognitive processes in different contexts and clinical conditions.

Parents play an important role in the development of children's emotion regulation (ER) skills-not only through their responses to children's emotions themselves, but also as role models by demonstrating their own ER strategies. Recent studies suggest that interbrain synchrony (IBS) can provide deeper insights into such parent-child dynamics at the neural level. IBS has been suggested as a neural marker of interpersonal processes such as bond formation and information exchange, and is known to vary by emotional valence and social context. This work aimed to investigate IBS during shared mother-child emotional experiences across different social contexts to study the neural mechanisms underlying mothers' and children's ER skills. An emotional imagery task, in which 36 mother-child dyads (child age 10-14 years) imagined experiencing emotional situations both with and without each other, was applied. Brain activity was simultaneously recorded using functional near-infrared spectroscopy (fNIRS) over the right frontopolar cortex, dorsolateral prefrontal cortex (rdlPFC) and temporoparietal junction (rTPJ). Results revealed that for all the regions analysed IBS only varied across valences in the with each other social condition, with higher IBS observed in negative and neutral scenarios compared to positive ones. Furthermore, IBS in the with each other social condition was positively associated with children's use of cognitive reappraisal (i.e., psychological reframing situations) across valences. For the negative valence, IBS also showed a positive association with mothers' ER difficulties. These findings suggest that dyadic IBS might reflect personal traits related to ER and provide a foundation for future investigations into the neural mechanisms underlying ER development.

Humans are highly social, and much of that sociality is regulatory: individuals manage the demands placed upon their bodies not only alone but through and with others. Attachment science has pursued how the brain accomplishes this for the better part of a century, and its most recent contribution has been neurobiological. Within the Social Neuroscience of Human Attachment (SoNeAt) programme, we previously specified a neuroanatomical architecture of two interacting systems and four domain-general modules for organised attachment, extended it to attachment disruption and disorganisation, and moved it from single brains to dyads through hyperscanning as part of Relational Neuroscience. What that work established energetically, through social allostasis, it did not specify computationally. Here we close that gap. Drawing on active inference, allostasis as interoceptive inference, and recent constructs of attachment as prediction, we propose the term social allostatic inference: the attachment system is one predictive-allostatic loop, the four modules are its successive stages, and organised, disrupted, and disorganised attachment are characteristic settings of the precision parameters that govern it. We extend the account to the caregiving system, which shares this architecture but infers rather than senses both the error that initiates its loop and the signal that terminates it. At the level of the dyad, interpersonal neural and bio-behavioural synchrony are read as indices of where regulatory work is invested rather than of bond quality directly. We address persistent misconceptions in trauma-informed practice and set out a measurement programme.

The transmission of trauma across generations, particularly among descendants of Holocaust survivors, presents a complex interplay of psychological and epigenetic adaptations. This study explored the long-term impacts of Holocaust trauma on the third and fourth generations, focusing on the quality of social-emotional ties and psychopathology, as well as the epigenetic variation in the oxytocin system, the Hypothalamic-Pituitary-Adrenal (HPA) stress axis, and the Sympathetic Nervous System (SNA). Involving 371 participants, including 186 third- and fourth-generation descendants of Holocaust survivors (54.8% women, mean age = 29.67), we employed DNA methylation analysis of saliva samples to uncover these dynamics. Our findings revealed that descendants exhibited significantly lower general attachment avoidance, and a DNA methylation pattern associated with stronger activation of the oxytocin system, indicating enhanced social bonding and social emotion regulation. Conversely, they showed distinct DNA methylation patterns in CRH, CRHBP, FKBP5, and NR3C1 genes linked to increased HPA axis activation and more pronounced stress reactivity. Despite the presence of these two DNA methylation patterns, no elevated levels of psychopathology were observed. Our results highlight the dual nature of trauma transmission, with descendants displaying both vulnerabilities and resilience. While stronger oxytocin system activation may support social cohesion and stress reduction, stronger HPA axis reactivity could ensure sustained vigilance and preparedness. Our findings thus underscore the intricate balance between genetic, epigenetic, and environmental factors in shaping resilience and offer insights into the potential for long-term growth following inherited trauma.

Alterations in brain structure following adversity show inconsistencies. Jointly considering maltreatment exposure alongside externalizing psychopathology may therefore prove helpful. However, few prospective studies currently follow up maltreated youth with high or low externalizing problems using neuroimaging assessments. A structural magnetic resonance imaging study was conducted using T1-weighted scans from 98 youth (MAge = 14.76, SDAge = 1.96; 51% girls) comparing participants with low (n = 29) and high (n = 29) maltreatment exposure to carefully matched non-maltreated controls (n = 40). Comprehensive assessments of maltreatment history and psychopathology were ascertained across two waves, applying the Maltreatment Classification System alongside caregiver- and teacher-reported externalizing problems. Neuroimaging was conducted at the second wave. We found dose-dependent amygdala volume reductions following maltreatment and particularly abuse exposure, primarily driven by the basolateral subregion. Interaction analyses revealed lower amygdalar and hippocampal volumes in youth exposed to more vs. less extensive maltreatment, but merely among those with elevated externalizing problems. These findings highlight the value of the ecophenotype model for elucidating neural correlates of maltreatment and its sequelae.

How does the brain prioritize information when visual scenes contain multiple sources of relevance? While emotionally evocative content has long been considered central to attentional capture, social content constitutes another key dimension of relevance. However, the neural mechanisms underlying the integration of these relevance dimensions remain unclear. We co-registered event-related potentials (ERPs) and eye movements while participants viewed complex scenes varying in social content (social, non-social) and emotional valence (positive, negative, neutral). Early ERP responses (P1) showed enhanced amplitudes for positive social images, suggesting that social relevance can mitigate the early-stage negativity bias. Social content also modulated the EPN, while emotional valence shaped later components (P300, LPC), with larger amplitudes for negative scenes. Eye-tracking measures mirrored these ERP effects: initial saccades were faster for social images, and fixation patterns indicated increased visual exploration for both positive and negative social scenes relative to neutral ones. Together, these results support a sequential appraisal process in which social content is prioritized at early perceptual stages, while emotional valence influences later evaluative processing. This pattern challenges the notion of a general negativity bias and underscores the interactive and stage-specific contributions of social and emotional relevance in affective scene perception.

The loss of a parent during childhood is a profound event with enduring impacts on psychological and emotional development. This study investigates the long-term effects of childhood parental loss on attachment patterns and openness to experience, with a focus on the epigenetic modulation of the oxytocin and dopamine systems. The sample included 371 participants (51.2% women, ages 26-43), of whom 33 experienced parental loss during childhood. In those individuals who lost a parent, findings revealed comparably lower attachment avoidance and a DNA methylation profile associated with a potential for increased oxytocin activity. Additionally, a DNA methylation profile associated with a potential for heightened dopamine activity was identified in this group, aligning with greater creativity. These findings highlight the intricate interplay of genetic and environmental factors in fostering resilience and personal growth, shedding light on the roles of oxytocin and dopamine in social bonding and the potential for long-term adaptation following early-life trauma.

Stress is a wide-spread phenomenon and associated with various detrimental health effects. A significant resource for stress buffering is social support. How social support is perceived, however, depends on a multitude of individual and interindividual factors. This study aimed to explore the stress-reducing properties of relationship-inherent variables. We investigated the association of attachment style, relationship quality and dyadic coping, with subjective and physiological stress responses to a psychosocial laboratory stressor in romantic partners. Seventy-nine couples participated (85 recruited, six dropouts), with one partner ("target") undergoing the Trier Social Stress Test and the other ("observer") observing the situation. Besides examining the role of targets' relationship variables, we also assessed the link between observers' relationship variables and targets' stress reactivity. We found that both targets' and observers' insecure-avoidant attachment scores were associated with targets' stress reactivity. In detail, while targets' insecure-avoidant attachment scores were negatively associated with targets' subjective stress experience, observers' insecure-avoidant attachment scores were positively associated with targets' heart rate reactivity. Further, higher insecure-avoidant attachment scores were linked to lower psychoendocrine covariance, i.e., a lower accordance between self-reported and cortisol stress responding. On the one hand, these data may suggest that under stress, insecure-avoidantly attached individuals suppress their experience of stress to preserve a sense of independence as part of their deactivating attachment strategy. The presence of an insecure-avoidantly attached partner during a stressful experience, on the other hand, seems to be a stressor rather than a source of support. Long-term, an insecure-avoidantly attached partner may negatively impact an individual's stress-related health and wellbeing.

Stress-related disorders are common in modern societies. What adds to the burden is empathic stress, arising when observing another’s stress elicits a stress response in the observer. In romantic couples, we investigated the association between empathic stress and adult attachment—a deep emotional bond between partners—to understand its inherent facets of risk and resilience. Psychosocial stress was induced in one partner (“target”) while the other passively observed the situation (“observer”). Stress reactivity was measured in both partners via salivary cortisol, heart rate, high-frequency heart rate variability, and questionnaires. Observers’ attachment representations were assessed using the Adult Attachment Interview. We found higher cortisol resonance—that is, proportionality in stress reactivity in targets and observers—in dyads with securely as opposed to insecurely attached (specifically insecure-dismissing) observers. Consistent with attachment as a resilience factor, our results suggest that securely attached individuals are physiologically more in tune with their partners during psychosocially stressful situations, possibly allowing for mutual understanding and triggering supportive behavior. However, suggesting a potential risk inherent to attachment security, in contexts of frequent or extreme partner stress, securely attached individuals may also be prone to excessive empathic stress activation and subsequent health impairments.

Parents and children often engage in joint play - a domain where mothers and fathers are thought to exhibit disparate behaviors and impact child development via distinct mechanisms. However, little is known about the neural substrates of mother-child and father-child play. In this fMRI study, we sampled brain activation of parents of pre-schoolers (N=88) during a novel event-related adaptation of the virtual ball-tossing game “Cyberball”. Mothers (N=40) and fathers (N=48) played “Cyberball” ostensibly with their own and an unrelated child, who consecutively included, excluded, and re-included parents. We found that overall, exclusion yielded comparable neural activations in mothers and fathers associated with mentalizing, saliency, and emotion-processing. We also observed a parent gender effect in several brain areas. While mothers exhibited increased reward- and attention-related activity during inclusion, fathers displayed increased mentalizing-related activity during exclusion. We also tested parents’ response to re-inclusion, which revealed a selective decrease in reward-related activity. Finally, exploratory analyses showed differences in parental brain activity as a function of child identity (own versus unrelated). Our study elucidates the common and distinct neural networks mothers and fathers engage during play interactions with their children, supporting theories that postulate only a partial differentiation of paternal and maternal parenting systems.

Humans are highly social, typically without this ability requiring noticeable efforts. Yet, such social fluency poses challenges both for the human brain to compute and for scientists to study. Over the last few decades, neuroscientific research of human sociality has witnessed a shift in focus from single-brain analysis to complex dynamics occurring across several brains, posing questions about what these dynamics mean and how they relate to multifaceted behavioural models. We propose the term 'Relational Neuroscience' to collate the interdisciplinary research field devoted to modelling the inter-brain dynamics subserving human connections, spanning from real-time joint experiences to long-term social bonds. Hyperscanning, i.e., simultaneously measuring brain activity from multiple individuals, has proven to be a highly promising technique to investigate inter-brain dynamics. Here, we discuss how hyperscanning can help investigate questions within the field of Relational Neuroscience, considering a variety of subfields, including cooperative interactions in dyads and groups, empathy, attachment and bonding, and developmental neuroscience. While presenting Relational Neuroscience in the light of hyperscanning, our discussion also takes into account behaviour, physiology and endocrinology to properly interpret inter-brain dynamics within social contexts. We consider the strengths but also the limitations and caveats of hyperscanning to answer questions about interacting people. The aim is to provide an integrative framework for future work to build better theories across a variety of contexts and research subfields to model human sociality.

Background: Many gaps exist regarding intergenerational transmission of attachment at preschool-age when narrative attachment measures first become available for children. We aimed to examine (1) concordance between parent and preschoolers’ attachment representations, (2) parental sensitivity during parent-child interactions as a potential proximate mechanism of intergenerational attachment transmission, and (3) the degree to which patterns of effects may vary as function of parent gender at this age. Methods: Our sample comprised 104 5-year-olds (53 girls) and one of their respective parents (n=52 mothers and n=52 fathers). We collected the Adult Attachment Interview (AAI) from parents and a novel adaptation of the story-completion method (Picture-based Story-Stem Battery; PSSB). Parent and child narratives were scored from transcripts using coding systems by Main and colleagues for AAIs and by Hill and colleagues and Robinson and colleagues for story completions. Parental behavioral sensitivity was rated using the NICHD Sensitivity Scales. Results and Conclusions: Parental attachment security and behavioral sensitivity were associated with child security. Mediation analysis supported an indirect path from parental insecure-dismissing AAI-classification to child insecurity via reduced sensitivity. Parent gender-specific analyses yielded effect sizes that were stronger (though still statistically comparable) for paths from maternal vs. paternal security and sensitivity to child security.