Physiological attunement and flourishing: understanding the influence of relationships on health

Abstract

Background:

Flourishing can be defined as the experience of life going well, a combination of feeling good and functioning effectively. High-quality relationships are essential to flourishing and long-term health. Physiological interdependence—such as synchronization of autonomic and endocrine systems—has been proposed as a mechanism supporting emotion regulation and social bonding.

Methods:

This scoping review maps the existing literature on physiological attunement in adult dyadic relationships. The review protocol was registered on the Open Science Framework (https://osf.io/295ge/) and followed JBI methodology for scoping reviews. PubMed and Scopus databases were searched. Eligible studies were original, quantitative, peer-reviewed articles published in English that examined physiological attunement in adult human dyads. Two reviewers independently screened and selected the studies.

Results:

A total of 62 studies were included. Attunement was observed in romantic partners, friends, strangers, and groups, involving heart rate, heart rate variability, skin conductance, respiration, cortisol, and alpha-amylase. Physiological attunement was shaped by relational context, emotional tone, individual traits (e.g., empathy, attachment style), and interaction features (e.g., touch, conflict, cooperation). While often linked to satisfaction, intimacy, and co-regulation, synchrony also appeared in distress contexts, sometimes reflecting stress contagion or co-dysregulation.

Conclusion:

Physiological attunement appears to be a context-sensitive process that may support or hinder wellbeing. It may represent a key biobehavioral pathway linking relationships to flourishing.

1 Introduction

The emerging concept of flourishing reflects a growing recognition of what constitutes holistic wellbeing (1). Its increasing use in wellbeing research can be traced back to the work of Keyes (2), who defined it as having “complete mental health … to be filled with positive emotion and to be functioning well psychologically and socially” (3). Another influential definition refers to it as “the experience of life going well … a combination of feeling good and functioning effectively” (4).

Although research aimed at assessing flourishing has expanded significantly over the past two decades, a universally accepted definition of the construct has yet to be established. The flourishing scales are generally subjective measurements of wellbeing. Rule et al. (3) compared seven scales that have been developed to measure flourishing among adolescent and adult populations. They found that the operationalization of wellbeing dimensions varies considerably between existing flourishing scales. Yet, they found that the measures share several commonalities as follows: multi-dimensionality, self-reporting of subjective wellbeing, an emphasis on everyday functioning, and relative stability across time.

According to VanderWeele (5), four key domains—family, work, school, and community—may serve as primary pathways through which flourishing is expressed across various areas of life, with their relative importance likely shifting across different stages of the lifespan. Flourishing is understood to encompass primarily psychological and social dimensions of human functioning (3).

Virtually every measure of health and wellbeing is improved by access to close social relationships and rich social networks (6). The social baseline theory states that close proximity to social resources is the baseline assumption of the human brain (6). This theory, which has bases on behavioral ecology and cognitive neuroscience, suggests that the human brain expects access to social relationships that mitigate risk and diminish the level of effort needed to meet a variety of goals (7). Social proximity would represent an innate, default or baseline strategy for human emotion regulation – one that does not require overt or deliberate action (6). Emotional regulation is considered a key skill for managing stress and to achieving flourishment (8).

Stress is traditionally conceptualized as a dynamic process triggered by actual or perceived environmental demands, which may be evaluated as either threatening or benign based on the individual’s available coping resources (9). The autonomic nervous system (ANS) and the hypothalamus-pituitary-adrenal axis (HPA axis) are considered the two main stress response systems of humans (9, 10). Objective measurement of physiological parameters that may vary according to the emotions experienced (like those linked to the ANS and to the HPA axis, e.g., cortisol measures) can lead to a better understanding of an individual`s psychological experiences.

A principal advantage of examining physiological responses during interpersonal interactions is the ability to explore theoretical questions that cannot be adequately addressed through self-reports or behavioral observations alone (11). Physiological data offer continuous insights into emotional states, including those that are unconscious or are not readily observable (12), and are not subject to the same demand effects that can bias self-reported data. Additionally, these responses can be monitored unobtrusively, enabling the assessment of psychological processes without disrupting the natural dynamics of interpersonal interactions (11). Shared physiological states are a phenomenon that has been investigated through these methods.

Physiological attunement refers to the temporal alignment of two or more people`s physiological states (13, 14). However, there is considerable diversity in the terminology used to refer to shared physiological states. Attunement, concordance, contagion, coregulation, coupling, covariation, entrainment, influence, linkage, and synchrony are some of the terms used to describe interdependence in partners` physiology. These terms sometimes reflect subtle conceptual distinctions regarding what is being assessed or denote specific analytical approaches. For instance, “coupling” and “synchrony” are often used to describe the correlation between partners’ physiological responses occurring at the same time point. In contrast, ‘‘attunement” and “coregulation” typically refer to the extent to which one partner’s physiological state predicts the other’s at a subsequent time point (15, 16). However, even these definitions are applied inconsistently across the literature.

The conceptual distinction between physiological synchrony and attunement—particularly as it pertains to concurrent versus lagged models—has gained attention in recent years, but it is not yet universally standardized or widely agreed upon. Many studies still use the term synchrony broadly and interchangeably with attunement, often without specifying whether the models employed are concurrent or lagged. The assumption that concurrent synchrony is purely situational and lagged synchrony inherently relational may oversimplify the dynamic and reciprocal nature of real-life interactions (17, 18). We argue that interpreting lagged physiological synchrony as definitive evidence of interpersonal, directional regulatory processes requires caution, as several confounding factors may influence the temporal structure of dyadic physiological data. For instance, individual differences in autonomic reactivity—such as variations in emotional responsiveness or health status—can yield time-lagged patterns that are intrapersonal rather than relational (19). Additionally, shared environmental stimuli or task characteristics may elicit temporally offset responses in both individuals (20). For these reasons, in the present work, we did not adopt a strict distinction between synchrony and attunement and used the terms interchangeably.

The widespread occurrence of synchrony in social interactions has become increasingly evident. This is largely due to advancements in continuous behavioral and physiological measurement techniques as well as the development of statistical methods capable of computing the concordance between two or more time series (14, 21, 22). Usually, to assess physiological attunement, the utilization of one or more of the following statistical approaches is necessary: correlation analysis, multilevel modeling, growth curve modeling, and cross-lagged panel analysis (23).

Autonomic mimicry enables emotion system coupling by allowing a receiver to implicitly mirror the physiological states of a sender—such as changes in pupil size, cardiovascular activity, and hormonal levels. Rooted in predictive coding mechanisms, this process helps the brain minimize prediction errors by aligning internal states with observed cues. Especially in infants, whose neocortex is underdeveloped, autonomic mimicry supports early emotion regulation by fostering adaptive responses and emotional attunement with caregivers (24).

Although autonomic mimicry is especially critical in infancy, it remains relevant in adults as a mechanism for emotion regulation. Adults continue to exhibit physiological mirroring, particularly in emotionally salient or intimate interactions. These responses reflect underlying predictive coding processes that help minimize emotional uncertainty and support co-regulation. While adults rely more on cognitive appraisal and learned regulation strategies, autonomic mimicry still facilitates emotional alignment and attunement, especially in contexts involving empathy, stress contagion, or social bonding (25–27).

Although the concepts of emotional contagion and physiologic attunement overlap in some ways, there are distinctions between them. Emotional contagion refers to the phenomenon where individuals unconsciously “catch” the emotions of others through automatic mimicry of facial expressions, vocalizations, postures, and movements, leading to shared emotional experiences. The process of emotional contagion appears to be facilitated by the mirror neuron system, which enables individuals to internally replicate observed behaviors and emotions (24).​ On the other hand, physiologic attunement involves the synchronization of physiological processes, such as heart rate, respiration, and hormonal levels, between individuals during social interactions, reflecting a state of mutual regulation and connection (28–30).

The literature presents a range of conceptual models for understanding mental health. One perspective suggests that mental health exists along a single continuum, extending from the presence of mental illness to states of happiness and wellbeing (3, 31). Within this framework, flourishing is positioned as the optimal end of the mental health spectrum, representing its most complete expression (3). Moreover, flourishing, conceived as a multidimensional and stable indicator of wellbeing, is inherently social in nature—an attribute rooted in the biological makeup of human beings (6). In its turn, physiological attunement appears to be an important mechanism for embodying the influence of sociality on organic functioning.

We propose that physiological attunement may represent a biological mechanism that supports, or in certain circumstances undermines, the experience of flourishing. Deepening the understanding of the relationship between social emotion regulation and flourishing may advance scientific insight into the prevention of emotional dysregulation— which is a barrier to wellbeing (32). Such insights may contribute to the development of more integrative therapeutic approaches, inform cultural and educational initiatives, and ultimately promote improved quality of life at both individual and societal levels.

Although there are some reviews on physiological attunement (11, 14) and at least one review on flourishing (3) available in the literature, to our knowledge, no existing review has synthesized current findings on physiological attunement in relation to the concept of flourishing. The present review addresses the research question concerning the occurrence of physiological synchrony across different types of adult relationships and subsequently examines how physiological attunement may influence individual wellbeing. We chose the scoping review approach because we intended to obtain a broad overview of the topic, identifying key concepts and mapping the literature, rather than testing a hypothesis (33).

2 Methods

2.1 Study design

A scoping review was carried out following the Arksey and O’Malley (34) guidelines: 1) identifying the research question, 2) identifying relevant studies, 3) study selection, 4) charting the data, and 5) collating, summarizing, and reporting results. The review also followed the JBI methodology for scoping reviews. The review protocol was registered on the Open Science Framework (OSF) (https://osf.io/295ge/). Institutional ethics board approval was not required.

2.2 Databases and search strategy

The scientific databases (SCOPUS and PubMed) were consulted, using keywords from the Medical Subject Headings (MeSH). The search strategy was [(physiologic interdependence OR physiologic attunement OR physiologic synchronization OR physiologic synchrony OR physiologic coregulation OR emotional contagion] AND [dyad* OR couple OR spouse OR partner OR romantic OR friend) AND (adult)]. To avoid missing important papers, we repeated the search using the keyword ‘cortisol’, as follows: [(cortisol interdependence OR cortisol attunement OR cortisol synchronization OR cortisol synchrony OR cortisol coregulation OR emotional contagion] AND [dyad* OR couple OR spouse OR partner OR romantic OR friend) AND (adult)]. Cortisol was selected as a focal point in the search strategy due to the well-established role of the hypothalamic–pituitary–adrenal (HPA) axis in responding to emotions and stress (35), as well as its widespread use as a biomarker in biological psychology and psychiatry. Two researchers performed the searches following the same strategy. The search took place between February 1^st and March 30^th 2025. Google Scholar was consulted for additional publications and grey literature, in addition, reference lists of included papers was verified.

2.3 Inclusion and exclusion criteria

This scoping review included quantitative studies published in peer-reviewed journals, in English, that investigated physiological attunement occurring in adult dyadic relationships. We limited the search to studies published since 2000 to prioritize research that employs contemporary statistical approaches and advances in technology for assessing physiological synchrony. This time frame reflects the growing availability of continuous physiological monitoring tools and the development of dynamic dyadic analysis methods that have enhanced the precision and ecological validity of synchrony research (15, 22). Review articles, editorials, letters to the editors, or case reports, were excluded from this review. Studies addressing physiological attunement in the context of mother-infant and father-infant relationships were also excluded. We decided to also exclude studies on emotional contagion because, as pointed out in the Introduction, this concept differs from physiological attunement. This review aimed to investigate a normal interpersonal physiological phenomenon (attunement), so studies involving specific diseases were also excluded. Studies assessing therapist–patient interactions were excluded because their structured, asymmetrical nature differs from every day, reciprocal relationships, potentially limiting the review’s focus on naturalistic interpersonal flourishing.

2.4 Data extraction

Five researchers were responsible for extracting the data independently. In the first stage, duplicate records were eliminated. Then, in the second stage, the studies were independently selected and analyzed by two researchers by reviewing titles and abstracts. In the third stage, the selected studies were analyzed by reading the full text to verify that they continued to meet the inclusion criteria.

In case of records with no complete agreement, a third researcher assessed them. The results of each stage were agreed upon, and discrepancies were resolved with the arbitration of a third researcher and, if necessary, a fourth researcher.

Finally, the following data was extracted: authors, year, country, purpose of the study, study design, sample characteristics, and major findings. The researchers used Microsoft Windows Office for both screening and citation management, without employing any specialized software for these tasks.

2.5 Generative artificial intelligence disclosure

Chat PDF AI was employed for data extraction from the included articles and Open AI Chat GPT-4.0 was used as a starting point in the writing of the Results and Discussion sections. Data extraction was supervised. The authors carefully reviewed and edited the AI generated texts as needed and take full responsibility for the content of the manuscript.

As this is a scoping review rather than a systematic review, we opted not to perform a formal assessment of study quality or risk of bias (33).

3 Results

The stage 1 (identification) of the search led to the retrieval of a total of 567 articles (Figure 1).

Figure 1

In stage 2 (screening and eligibility), the application of the inclusion and exclusion criteria, plus removal of duplicated articles, resulted in the exclusion of 503 articles and the inclusion of 62 articles in final analysis.

The most common reasons for exclusion of articles were: studies focusing on parent–infant relationships (mother–infant or father–infant); studies involving samples composed exclusively of children or adolescents; theoretical, review, and methodological articles; studies centered on specific diseases; and studies focused on emotional contagion.

In stage 3 (critical analysis of studies), all 62 studies found were evaluated in terms of purpose, study design, sample characteristics, and main findings. The screening of references lists of initially included articles failed to add any extra publication for final analysis. Figure 1 illustrates the results of the study screening strategy.

This scoping review synthesized evidence from 62 quantitative studies examining physiological attunement in adult interpersonal interactions. Overall, findings support the existence of physiological synchronization across multiple systems—particularly the autonomic nervous system (ANS) and hypothalamic-pituitary-adrenal (HPA) axis—in a variety of dyadic and group contexts. These studies were charted into five analytical categories based on the physiological system investigated and the context of interpersonal interaction: (1) autonomic nervous system attunement in romantic partners during conflict situations; (2) autonomic attunement in romantic partners during non-conflict interactions; (3) cortisol attunement in romantic partners; (4) autonomic attunement in non-romantic dyads (friends, strangers, and groups); and (5) cortisol attunement in non-romantic dyads. All studies involved adult participants and employed quantitative methodologies.

The five analytical categories were derived inductively from the reviewed literature to facilitate a more coherent organization of the data. The present Results section brings 5 tables summarizing the studies that were included in each of the abovementioned analytical category. It also includes brief observations on sample characteristics, patterns and trends in methodology, as well as what the reviewed studies collectively show about each form of attunement.

3.1 Autonomic nervous system attunement in romantic partners during conflict situations

Twelve studies examined autonomic nervous system (ANS) attunement in romantic couples during conflictual or emotionally charged interactions. Table 1 briefly describes the 12 included studies. Measures included heart rate (HR), heart rate variability (HRV), respiratory sinus arrhythmia (RSA), electrodermal activity (EDA), and blood pressure. The majority of studies employed laboratory-based paradigms (e.g., conflict discussions, emotionally salient conversations, structured relational tasks), though a few incorporated longitudinal or semi-naturalistic designs. Most samples comprised heterosexual couples, with average ages ranging from early 20s to mid-50s, and relationship durations spanning from newly formed to long-term marriages. Most studies employed used statistical techniques such as multilevel modeling, actor-partner interdependence modeling, and correlational analysis. Geographically, studies were predominantly conducted in North America and Western Europe, with limited cultural or demographic diversity.

Conflict discussions consistently elicited in-phase or anti-phase physiological synchrony, modulated by factors such as partner empathy (39, 42), perspective-taking (30), or trauma history (44). Several studies linked higher attunement to emotional or relational outcomes, including increased marital satisfaction (41), while others identified potential physiological costs, such as elevated inflammatory markers following high HRV synchrony during conflict (37).

3.2 Autonomic nervous system attunement in romantic partners during non-conflict situations

Nine studies investigated autonomic attunement in romantic partners during affiliative, cooperative, or intimate interactions. Table 2 briefly describes the 9 included studies. The studies applied tasks involving eye-gazing, interpersonal touch, emotional sharing, imitation, and sexual activity. Measured parameters included HR, HRV, respiration, and skin conductance. Most studies used multilevel statistical approaches such as multilevel modeling or oscillator-based models. Samples consisted mostly of heterosexual couples in young to early adulthood, with average ages ranging from approximately 23 to 30 years, and relationship durations varying from a few months to several years. All studies were conducted in North America or Europe, and only one included same-sex dyads.

Overall, physiological attunement was consistently observed across conditions involving emotional connection or physical intimacy. For instance, interpersonal touch reliably enhanced autonomic coupling (47, 49), and greater attunement was associated with higher sexual satisfaction (51) and stronger empathic connections (53). Conversely, constraints on natural interaction—such as prescribed sexual positions—diminished synchrony (16). In some cases, synchrony was asymmetrical or context-dependent, such as when only female partners’ emotional states predicted autonomic reactivity in male partners (52, 53).

3.3 Cortisol attunement in romantic partners

Twenty studies examined hypothalamic-pituitary-adrenal (HPA) axis attunement via salivary cortisol levels in romantic couples. Table 3 briefly describes the 20 included studies. These studies employed both laboratory paradigms (e.g., conflict discussions, Trier Social Stress Test) and ecological momentary assessments (e.g., daily diary or multiday cortisol sampling). The studies investigated both younger and older adult couples across diverse countries, including the USA, Germany, Portugal, Israel, China, and Canada. Sample sizes varied substantially, ranging from 56 to over 600 participants, with most studies focusing on heterosexual couples and a few including older populations (e.g., 68, 70). The statistical methodologies employed were robust and varied, including dyadic multilevel modeling, actor-partner interdependence models, longitudinal growth curve modeling, and cross-lagged regressions. The conceptual heterogeneity in how “cortisol attunement” was defined and interpreted across studies is noteworthy.

Across studies, consistent evidence emerged supporting the presence of cortisol attunement between partners, with several investigations reporting co-variation in diurnal cortisol rhythms and acute cortisol reactivity during conflict discussions or stress-inducing tasks (e.g., 28, 56, 66). Attunement tended to increase under emotionally intense or stressful conditions, particularly in couples experiencing high marital strain, low social support, or strong attachment insecurities (e.g., 67, 71). Interestingly, higher cortisol attunement was sometimes linked to maladaptive outcomes—such as elevated inflammation markers or dysregulated HPA patterns—especially when partners were emotionally distressed. Conversely, positive relational behaviors, empathic exchanges, and shared routines were associated with healthier cortisol synchrony and better relational outcomes over time, particularly in older couples (e.g., 29, 68). A recurring pattern across contexts was that partners influence one another’s cortisol levels both in the moment and over time, highlighting the biobehavioral interdependence inherent in close relationships.

3.4 Autonomic attunement in non-romantic relationships (friends, strangers, and groups)

Fourteen studies evaluated autonomic attunement in non-romantic social settings, including close friendships, strangers, and groups. Table 4 briefly describes the 14 included studies. Experimental paradigms ranged from cooperative games and joint tasks to emotionally salient conversations and stress-inducing scenarios. Most studies were conducted in North America and Europe, with participants primarily composed of university students or young adults (mean ages typically in the early to mid-20s). Several studies used same-sex dyads or small teams, few studies included cross-gender pairings.

A consistent finding across studies was the emergence of autonomic attunement during shared emotional or interactive experiences. For instance, greater physiological synchrony was associated with enhanced team performance (73), successful cooperation (78), or positive affective behavior during group deliberation (80). However, attunement was not uniformly beneficial—one study suggested that higher physiological attunement could undermine autonomic stability (75).

Key modulators of attunement included visual contact, task novelty, social roles, and emotion regulation strategies. Visual access amplified attunement effects (78), and emotion regulation through stress reappraisal led to more adaptive cardiovascular responses at both individual and dyadic levels (79). In group settings, synchrony at the collective level (not just between pairs) predicted affective outcomes, and task-induced synchrony emerged even among stranger dyads (83).

3.5 Cortisol attunement in friends and groups

Seven studies investigated the attunement of endocrine responses—particularly cortisol—within friendships, strangers, and groups. Table 5 briefly describes the 7 included studies. All studies employed salivary biomarkers and used experimental or semi-naturalistic tasks to induce emotional engagement or stress, including structured conversations, co-rumination, psychosocial stress tests (e.g., TSST), and outdoor group activities. Most studies were conducted in the United States, with a predominance of female participants and young adult samples (mean age range: 18–24 years), except for Denk et al. (90), which included a broader age distribution. Methodologically, multilevel modeling, actor–partner interdependence models, and linear regressions were commonly used to analyze dyadic and group-level hormone data.

Consistently, cortisol attunement emerged across various relational contexts. Female friendship dyads demonstrated aligned cortisol responses at baseline and following stress exposure, especially when co-rumination was present (88). On the other hand, Cook (89) found that alpha-amylase synchrony was stronger in low-quality friendships, possibly reflecting heightened vigilance or conflict sensitivity. Also, greater affective sharing or self-disclosure was associated with more similar cortisol reactivity between unfamiliar dyad partners (92). Notably, the presence of stress did not always enhance attunement—Denk et al. (90) found stronger cortisol and alpha-amylase synchrony in non-stressful group conditions than in stress-inducing ones, suggesting that synchrony may also emerge in emotionally regulated or low-threat contexts.

Additional important themes emerged from our review of physiological attunement and will be addressed in the following section.

4 Discussion

Several implications have emerged inductively from the body of literature reviewed in this study. In the following subsections, we explore key themes that contribute to a more nuanced understanding of physiological attunement in adult relationships. First, we examine how physiological attunement varies according to the emotional valence of interpersonal interactions. Next, we consider the role of individual differences, such as empathy and personality traits, in shaping interpersonal synchrony. We also discuss how the duration and modalities of interaction—such as verbal communication, eye contact, and touch—may influence the emergence of physiological attunement. Additionally, we address the associations between physiological attunement and health outcomes across various relational contexts, followed by a closer look at how physiological attunement may reflect relationship quality in romantic dyads. We then consider the link between group-level synchrony and collaborative performance, and finally, we reflect on sex differences in the propensity to exhibit physiological attunement. Together, these thematic areas offer important insights into the dynamic and context-sensitive nature of physiological attunement and its relevance for mental and relational well-being.

4.1 Variation in physiological attunement according to the emotional valence of interpersonal interactions

The evaluation of included studies indicates that autonomic attunement is often stronger during conflictual or emotionally charged negative interactions. For example, during marital conflicts, couples showed higher HRV attunement, and this was associated with elevated inflammatory markers and negative affect, suggesting a stress-reactive form of attunement (30, 37). Electrodermal synchrony also increased during negative conversations in couples, possibly reflecting heightened arousal or vigilance (39). Cortisol attunement was sometimes enhanced during conflict or strain, suggesting that couples may “tune in” physiologically in ways that amplify shared stress (60, 66).

In contrast, positive interactions (e.g., affectionate conversations, support exchanges) tend to promote in-phase synchrony that is associated with positive emotional states and relational benefits. Shared positive emotions were associated with greater physiological attunement, higher-quality marital interactions, and greater satisfaction (41). During positive conversations, heart rate synchrony was linked to higher relationship satisfaction (42). During sexual or intimate activities, higher HRV attunement was associated with greater sexual satisfaction (16, 51). Similarly, cortisol attunement emerged more robustly in couples with higher emotional support, positive daily interactions, or shared routines, often predicting better long-term wellbeing and relational satisfaction (29, 68, 70).

Hence, physiological attunement can either reflect harmony or shared distress, depending on the emotional valence and quality of the interaction. Synchrony is not inherently positive or negative—it is shaped by context and relational dynamics (28, 66, 67). This dual nature has direct implications for flourishing. When interpersonal attunement emerges within a supportive and emotionally safe environment, it may act as a physiological mechanism that reinforces connection and emotional regulation—key ingredients of flourishing. Conversely, in relationships marked by chronic strain or emotional dysregulation, attunement may amplify stress and relational dissatisfaction, potentially undermining well-being. Thus, physiological attunement could be considered a dynamic biological substrate through which relationships shape, sustain, or impair individual flourishing (28, 66, 67).

4.2 Influence of empathy and personality traits on interpersonal physiological attunement

Empathy may enhance interpersonal attunement by increasing emotional sensitivity and responsiveness, thus facilitating biobehavioral alignment at both cognitive and physiological levels. Empathic concern, measured by self-report tools such as the Interpersonal Reactivity Index (IRI), was positively associated with cardiac attunement during romantic interactions. When partners demonstrated greater trait empathy, their heart rate (HR) patterns were more likely to align (42). In a study examining couples under pain conditions, dyads with higher trait empathy showed stronger HR and respiratory synchrony, especially when touch was involved (49). Perspective-taking, considered one of the components of empathy (93), was shown to enhance autonomic attunement in couples during conflict discussions. Those induced to take their partner’s perspective exhibited greater alpha-amylase synchrony—a marker of sympathetic activity (30).

During shared empathy-for-suffering tasks, couples showed attunement in electrodermal and cardiac responses (53). Empathic accuracy refers to the ability to accurately infer the specific thoughts and feelings of another person in real time during social interaction (94). In female friendship dyads, empathic accuracy was significantly associated with physiology–experience linkage, suggesting that individuals with greater empathic sensitivity may physically mirror their partner’s emotional experiences (81).

Some studies also identify other traits that significantly influence the depth and quality of physiological attunement. Attachment style plays a critical role. In adults, attachment styles are commonly described as secure, anxious-preoccupied, dismissive-avoidant, or fearful-avoidant (95, 96), reflecting differing degrees of comfort with intimacy, dependence, and emotional expression. Secure adults typically engage in trusting and balanced relationships; anxious-preoccupied individuals seek closeness but often worry about rejection; dismissive-avoidant individuals emphasize independence and downplay emotional needs; and fearful-avoidant individuals desire connection but fear vulnerability, often due to unresolved relational trauma. Avoidant partners demonstrated weaker synchrony during resting and affectionate conditions, while anxious attachment was associated with heightened cortisol reactivity, particularly during emotionally threatening interactions (15, 55, 67). Furthermore, social anxiety was inversely associated with physiological attunement. Dyads with members scoring high in social anxiety exhibited less cardiac attunement, especially during novel or demanding social tasks (85).

The evidence suggests that empathy and certain personality traits may serve as dispositional catalysts or barriers to physiological attunement, with direct implications for human flourishing. Traits such as empathic concern and perspective-taking appear to promote synchrony in autonomic and endocrine systems, enabling individuals to emotionally and physiologically “tune in” to others in meaningful ways (30, 42, 49). This biobehavioral alignment likely fosters social bonding, emotional safety, and mutual regulation, which are key elements of flourishing as a relational and psychological construct (4, 5). Conversely, traits associated with emotional withdrawal or threat sensitivity, such as avoidant attachment and social anxiety, tend to dampen synchrony (15, 55, 85). These findings suggest that flourishing is not only a product of environmental or relational conditions but is also partly shaped by the individual’s internal dispositional landscape. When personality traits support emotional openness and attunement, physiological systems may align in ways that reinforce well-being. In contrast, dispositional barriers to connection may impair this alignment, potentially limiting opportunities for relational growth and psychological thriving (67, 81).

4.3 Duration and modalities of interaction as determinants of physiological attunement

Many of the reviewed studies have showed that strangers can develop physiological synchrony within minutes, suggesting that a long history of relational bonding is not a prerequisite. Stranger dyads achieved significant cardiac interbeat interval linkage during brief emotionally themed conversations or writing tasks, even when they were completely unacquainted before the experiment (74). In joint tasks like cooperative or competitive games, strangers displayed skin conductance and heart rate synchrony within a single session (76). In group contexts, first-time collaborators displayed converging cortisol responses and sympathetic arousal after completing problem-solving or adventure-based activities (80, 87). Thus, synchrony can emerge rapidly when interpersonal engagement is high and the context is emotionally salient.

Verbal communication, especially when emotionally meaningful or affiliative, promotes and amplifies physiological synchrony. Couples engaged in verbal conflict resolution or emotional disclosure showed autonomic and hormonal attunement, including synchrony in HR, EDA, cortisol, and alpha-amylase (40, 41, 71). Emotionally supportive conversations among friends enhanced synchrony in cortisol and alpha-amylase (88, 89). In task-based stranger dyads, talking during interaction increased the physiologic attunement corresponding to the sympathetic branch and improved social outcomes, compared to no-talking conditions (77).

Visual contact also exert a powerful role to promote physiological attunement. Gazing into each other’s eyes enhanced HR and respiratory synchrony among romantic partners—even in the absence of speech (15). In cooperative games like the Prisoner’s Dilemma, face-to-face conditions produced significantly stronger skin conductance synchrony and higher rates of cooperation than visual-blocked conditions (78).

In addition, touch consistently emerges as a robust, nonverbal promoter of physiological synchrony as well. When couples were allowed to hold hands or touch forearms, EDA attunement increased significantly—regardless of emotional valence or task content (47). During pain empathy tasks, touch enhanced synchrony in HR and respiration, particularly among couples high in trait empathy (49). Under stress (e.g., Trier Social Stress Test), partner presence and proximity—especially involving physical closeness—was associated with stronger RSA and cortisol attunement (64).

Evidence indicates that physiological attunement is a flexible and dynamic phenomenon that does not depend on long-term familiarity. It is highly sensitive to behavioral engagement, and can be modulated by multiple sensory and communicative channels, both verbal and nonverbal. These findings carry important implications for flourishing as a dynamic and interactionally grounded construct. If physiological attunement can arise spontaneously in short-term interactions—when facilitated by emotional resonance, gaze, speech, or touch—it suggests that the capacity to biologically connect is widespread and adaptable, offering potential for well-being even in newly formed or transient social ties. Encouraging environments that foster empathic communication, visual presence, and safe touch may thus enhance both social cohesion and individual well-being at a physiological level.

4.4 Associations between physiological attunement and health outcomes across relationship contexts

Regarding romantic couples, autonomic attunement during conflict was sometimes linked to increased inflammatory markers and greater emotional distress. For example, HRV synchrony during marital conflict predicted higher levels of IL-6, a pro-inflammatory cytokine (37). Couples with high synchrony in negative affect and physiological stress during arguments were more likely to report poor relational quality and psychological distress (30). Insecure attachment styles and unresolved trauma led to weaker RSA synchrony and greater cortisol reactivity, which are markers of emotional and physiological dysregulation (44, 67). Thorson and West (75) found a significant negative correlation between physiological synchrony and individual physiological stability; participants who were more influenced by their partners exhibited less stable physiological responses of their own. In a longitudinal study, higher cortisol covariation predicted higher non-HDL cholesterol levels over time, suggesting that physiological attunement may pose health risks (68). On the other hand, some studies showed that couples who exhibited cortisol synchrony during daily life were more likely to report greater relationship satisfaction, emotional closeness, and psychological wellbeing (29, 70).

With respect to friendship, in studies of close friends, co-rumination and emotional sharing that led to cortisol synchrony were associated with higher emotional burden and stress transmission (88, 89). However, supportive conversations among friends increased physiological synchrony and were associated with relational satisfaction and affective alignment, which may offer protective benefits over time (84).

These findings suggest that physiological attunement is not inherently beneficial or harmful; rather, its impact depends on interaction quality, emotional tone, and individual differences such as attachment and empathic capacity. In this sense, synchronization can either reinforce co-regulation processes that support flourishing or co-dysregulation dynamics that exacerbate stress and health risk.

4.5 Links between physiological attunement and relationship quality in romantic dyads

Heart rate and HRV synchrony during positive conversations, mutual gaze, or emotional sharing were linked with greater empathy, relationship satisfaction, and emotional intimacy (15, 42). During sexual activity, HRV synchrony was positively correlated with sexual satisfaction and partner responsiveness, reinforcing its role in emotional and physical intimacy (51). Cortisol attunement across days was associated with daily connectedness and higher relationship satisfaction (29, 70).

Conversely, during conflict interactions, high autonomic synchrony sometimes predicted emotional strain and hostile affect (30, 37). In distressed couples, synchrony in negative affect was related to lower communication quality and greater emotional vulnerability (40).

Importantly, this context-sensitivity has direct implications for flourishing, understood as a state of optimal emotional, relational, and psychological functioning (4, 5). When physiological attunement emerges in healthy, emotionally attuned romantic relationships, it may act as a biological substrate that supports individual and relational flourishing. Conversely, in strained or dysregulated relationships, synchrony may contribute to relational stress and compromise long-term well-being.

4.6 Group-level physiological attunement and its relation to task performance

In a study by Guastello et al. (73), triads working on a creative group task showed that HR synchrony predicted higher group output, better collaboration, and greater consensus. Gordon et al. (80) found that in triads completing cooperative problem-solving tasks, higher within-group HR synchrony predicted greater engagement, positive affective behavior, and successful cooperation. Interestingly, group-level synchrony (across all three members) was a better predictor of outcomes than dyadic synchrony. In Behrens et al. (78), participants playing a social dilemma game in pairs showed greater skin conductance synchrony during face-to-face interactions, which correlated with higher cooperation rates and mutual trust.

Also, in collaborative attentional tasks, Vanutelli et al. (76) showed that attunement was stronger during novel tasks and increased when participants received a positive feedback, which related to better adaptation and group cohesion. In consequence, greater physiological attunement in groups is associated with improved performance in collaborative tasks.

These findings converge to indicate that physiological synchrony in groups serves as a marker of shared cognitive and emotional engagement, facilitating smoother interpersonal coordination and more effective collective action. In broader terms, such alignment may support dimensions of flourishing in group and community settings, by fostering prosocial behavior, shared purpose, and mutual responsiveness.

4.7 Sex differences in the propensity for physiological attunement

In romantic couples, females were often found to be more physiologically reactive or attuned during emotionally intense interactions. In emotionally evocative conversations, female partners tended to show stronger electrodermal and HRV synchrony, whether they were in a disclosing or a listening role (53). Trait empathy, which tends to be higher in women, was linked to stronger physiological attunement (42), and women’s empathic concern correlated more consistently with in-phase physiological attunement. In conflictual or stressful contexts, men were sometimes less physiologically reactive or showed delayed synchronization compared to female partners (30, 40). However, some findings suggest that men’s physiological states are more influenced by their female partners’ responses (37). In group and cooperative tasks, no consistent sex differences were observed in synchrony levels, though role (leader vs. follower) and task type seemed to influence who synchronized with whom (80, 85).

These sex-related patterns in attunement likely reflect a complex interplay of biological sensitivity and socialized emotional roles. From a flourishing perspective, they underscore the relevance of interpersonal sensitivity and responsiveness as foundational elements of well-being. If flourishing encompasses emotional resonance, relational quality, and mutual regulation (4, 5), then sex differences in physiological attunement may influence how individuals engage in supportive, co-regulatory interactions that sustain psychological health. Understanding these variations may help tailor relational interventions and emotional education strategies that respect individual differences while enhancing pathways toward relational flourishing. Moreover, this is remarkable that the current literature on physiological attunement is largely based on heterosexual dyads, reporting biological sex (male/female), often without attending to gender identity and gender roles.

4.8 Lessons learned from physiological attunement and its importance for human flourishing

The findings of this review suggest physiological attunement may be a key biobehavioral pathway linking relationships to flourishing. Across multiple studies, physiological attunement in romantic couples, friends, and social groups was associated with emotional closeness, mutual regulation, empathy, and stress buffering—core elements of meaningful and flourishing relationships (29, 42, 49). In contexts of support, intimacy, and cooperation, attunement appeared to facilitate affective alignment and promote psychological and even physiological health (51, 70).

Conversely, in contexts marked by conflict, unresolved trauma, or insecure attachment, synchrony could reflect co-dysregulation and shared distress (37, 67), which may compromise wellbeing over time. These dual possibilities highlight physiological attunement as a dynamic and context-sensitive process—capable of enhancing flourishing when grounded in emotional safety and reciprocity, but potentially detrimental when reinforcing relational strain. Thus, physiological attunement may not only reflect—but actively support or hinder—the developmental trajectory of individual and relational flourishing. In Figure 2, we propose a visual expression of a conceptual model of the relationship between biological attunement and flourishing.

Figure 2

The widespread presence of physiological synchrony across diverse relationship types suggests it may serve an evolutionarily adaptive function in social mammals. Evidence from this review indicates that synchrony emerges even in brief interactions and among strangers (85, 87), supporting the idea of a biologically embedded drive toward alignment that promotes social cohesion, cooperation, and collective regulation. This view aligns with theories in evolutionary psychology and social neuroscience proposing that alignment at behavioral, neural, and physiological levels facilitates trust and coordinated action (24).

Polyvagal theory (97) proposes that the mammalian nervous system enables sociality to function as a neuromodulator—calming physiological responses and optimizing bodily functions. According to this theory, social connection allows humans to experience a sense of safety and access positive emotional states that actively suppress threat-related reactions. Social engagement helps shift the autonomic state from defense to one that supports homeostasis. When individuals feel safe, they become more open to others and engage in trusting social interactions that promote coregulation (97). Together with Social Baseline Theory (6), these ideas offer a robust conceptual framework for understanding the role of sociality in emotion regulation, well-being, and flourishing.

Although this review focuses on adults, it is worth noting that physiological attunement is likely a lifespan phenomenon, playing distinct roles at different developmental stages. In infancy, synchrony between caregivers and infants supports emotional regulation and attachment formation (24, 98). These early co-regulatory patterns may scaffold future relational attunement. During adolescence, synchrony may become more complex, as individuals negotiate autonomy and social sensitivity (99). In adulthood, it facilitates intimacy, empathy, and pair bonding, with studies showing increased physiological interdependence in long-term couples (42, 51, 68, 70). In older adulthood, this attunement may culminate in deeply embodied mutual regulation, with some evidence suggesting shared physiological decline and increased mortality risk following the loss of a spouse (100, 101). Thus, attunement appears to be a plastic and context-sensitive process, supporting regulation, bonding, and resilience across the human lifespan.

Synchrony increases the predictability of social interaction: It is easier to know what your partner is going to do next if you are synchronized. But this reduction in prediction error comes at the expense of redundancy and reduced information exchange (14, 102, 103). No behavior is optimal in all contexts. What is considered optimal depends on the specific goal or context in which the behavior occurs. If a dyad`s goal is to increase feelings of closeness and similarity, increasing interpersonal synchrony may be optimal. Contrastingly, decreasing interpersonal synchrony may better serve them if their goal is to generate divergent solutions to a complex problem (14). Successful partners dynamically move in and out of synchrony, for instance, to correct moments of misunderstanding, miscoordination, and dysregulation (14).

As a result of the present review, we were able to identify some gaps in this research field. First, there was variation in how physiological attunement was defined and measured, contributing to conceptual heterogeneity. Second, relatively few studies examined long-term health or wellbeing outcomes, leaving open questions about the sustained impact of physiological attunement. Third, most of the included studies categorized participants as male or female based on biological sex, without accounting for gender identity or sexual orientation. This fact limits generalizability to more diverse populations. This is particularly relevant given that gender identity and gender role socialization are known to influence emotional expression, empathic behavior, and interpersonal regulation.

5 Limitations

The present work has some limitations. First, most included studies did not assess flourishing directly and the physiological indicators measured not necessarily align with validated flourishing constructs. In other words, the included studies were not selected or categorized based on whether they addressed flourishing explicitly or implicitly. As a result, theoretical links between physiological attunement and flourishing may lack conceptual strength. Second, the scoping review format is appropriate for mapping literature but does not support causal inference. Hence, the present review does not allow us to draw causal or mechanistic conclusions, neither specific practical implications. Third, given the substantial variation in how physiological attunement is defined and measured, it is possible that some relevant articles were inadvertently excluded from the present review.

6 Conclusion

Flourishing, as a multidimensional and stable construct of well-being, has predominantly social characteristics rooted in the biological nature of human beings. Given the importance of mental health for overall well-being and the continuum on which mental health operates, physiological attunement may represent a key mechanism through which sociality influences bodily functioning. It can promote well-being when interpersonal relationships are supportive and healthy, but may also contribute to stress contagion and increase vulnerability to illness in the context of abusive or dysregulated relationships.

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