Relationship satisfaction, feelings of closeness and annoyance, and linkage in electrodermal activity

Physiological linkage refers to moment-to-moment, time-linked coordination in physiological responses among people in close relationships. Although people in romantic relationships have been shown to evidence linkage in their physiological responses over time, it is still unclear how patterns of covariation relate to in-the-moment, as well as general levels of, relationship functioning. In the present study with data collected between 2014 and 2017, we capture linkage in electrodermal activity (EDA) in a diverse sample of young-adult couples, generally representative and generalizable to the Los Angeles community from which we sampled. We test how naturally occurring, shifting feelings of closeness with and annoyance toward one's partner relate to concurrent changes in levels of physiological linkage over the course of 1 day. Additionally, we examine how linkage relates to overall relationship satisfaction. Results showed that couples evidenced significant covariation in their levels of physiological arousal in daily life. Further, physiological linkage increased during hours that participants felt close to their romantic partners but not during hours that participants felt annoyed with their partners. Finally, those participants with overall higher levels of relationship satisfaction showed lower levels of linkage over the day of data collection. These findings highlight how individuals respond in sync with their romantic partners and how this process ebbs and flows in conjunction with the shifting emotional tone of their relationships. The discussion focuses on how linkage might enhance closeness or, alternatively, contribute to conflict escalation and the potential of linkage processes to promote positive interpersonal relationships. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

It does not need two: Assessing physiological linkage from videos across the valence dimension

The phenomenon of physiological linkage describes similar fluctuations of two individuals' physiology, for example, the cardiac inter-beat interval (IBI). Physiological linkage is a well-documented occurrence in research settings of interacting dyads but the literature on non-interacting dyads, that is, someone watching a video of another person, is sparse. The current study investigated whether physiological linkage, based on IBI, occurs from watching videos where strangers report about personal (neutral, positive, negative non-traumatic, and negative traumatic) experiences. Videos were produced with six individuals and then presented to observers (N = 26). Time-frequency-domain cross-wavelet analyses supplemented by threshold-free cluster enhancement (TFCE; to account for multiple testing) showed significant physiological linkage between the IBI of observers and persons in the videos for 16 out of the 21 tested videos. Although significant physiological linkage also emerged for neutral videos and positive, negative valence videos led to such associations more reliably. This study shows that physiological linkage can be investigated in highly controlled conditions based on video stimuli paving the path for experimental manipulation in future research. Furthermore, due to the provision of information on time and frequency, the use of cross-wavelet analysis is encouraged to learn more about factors modulating physiological linkage. The current study presents the next step toward identifying psychophysiological causal and modulating factors of physiological linkage.

An Exploratory Study of Physiological Linkage Among Strangers

The present study explores physiological linkage (i.e., any form of statistical interdependence between the physiological signals of interacting partners; PL) using data from 65 same-sex, same ethnicity stranger dyads. Participants completed a knot-tying task with either a cooperative or competitive framing while either talking or remaining silent. Autonomic nervous system activity was measured continuously by electrocardiograph for both individuals during the interaction. Using a recently developed R statistical package (i.e., rties), we modeled different oscillatory patterns of coordination between partner's interbeat interval (i.e., the time between consecutive heart beats) over the course of the task. Three patterns of PL emerged, characterized by differences in frequency of oscillation, phase, and damping or amplification. To address gaps in the literature, we explored (a) PL patterns as predictors of affiliation and (b) the interaction between individual differences and experimental condition as predictors of PL patterns. In contrast to prior analyses using this dataset for PL operationalized as covariation, the present analyses showed that oscillatory PL patterns did not predict affiliation, but the interaction of individual differences and condition differentially predicted PL patterns. This study represents a next step toward understanding the roles of individual differences, context, and PL among strangers.

Automated affect classification and task difficulty adaptation in a competitive scenario based on physiological linkage: An exploratory study

In competitive and cooperative scenarios, task difficulty should be dynamically adapted to suit people with different abilities. State-of-the-art difficulty adaptation methods for such scenarios are based on task performance, which conveys little information about user-specific factors such as workload. Thus, we present an exploratory study of automated affect recognition and task difficulty adaptation in a competitive scenario based on physiological linkage (covariation of participants' physiological responses). Classification algorithms were developed in an open-loop study where 16 pairs played a competitive game while 5 physiological responses were measured: respiration, skin conductance, electrocardiogram, and 2 facial electromyograms. Physiological and performance data were used to classify four self-reported variables (enjoyment, valence, arousal, perceived difficulty) into two or three classes. The highest classification accuracies were obtained for perceived difficulty: 84.3% for two-class and 60.5% for three-class classification. As a proof of concept, the developed classifiers were used in a small closed-loop study to dynamically adapt game difficulty. While this closed-loop study found no clear advantages of physiology-based adaptation, it demonstrated the technical feasibility of such real-time adaptation. In the long term, physiology-based task adaptation could enhance competition and cooperation in many multi-user settings (e.g., education, manufacturing, exercise).

Physiological linkage among successful high-status women in international teams

In contemporary society, decisions are often made by teams whose members represent different nationalities and genders. In the current work, participants from 55 countries formed groups of 3 to 4 people to select one of the 5 firms in a mock firm search. In all groups, one woman was randomly assigned to have higher status than her groupmates; she was also surreptitiously instructed to persuade her group to select one (randomly assigned) firm. We measured cardiac interbeat intervals for participants throughout the decision-making process to assess physiological linkage—the degree to which a ‘sender’s’ physiological response predicts a ‘receiver’s’ physiological response at a subsequent time interval. On average, high-status women were successful at persuasion. The physiological responses of successful high-status women were also predicted by the responses of their female groupmates: stronger linkage to female group members during the task was associated with success at persuading the group. Successful high-status women were also perceived as more persuasive than others in the group. This work shows that the link between status and successful persuasion generalizes to women among heterogeneous international teams. It also suggests that attention to others—often associated with physiological linkage—may be useful in persuading others during decision-making.

Exploring Physiological Linkage in Same-Sex Male Couples

We explore physiological linkage (i.e., covariation of physiological channels between interacting partners; PL) among 34 same-sex male couples. Interbeat interval, an indicator of cardiovascular arousal, was collected across four conversational contexts in the lab: (1) a baseline period that did not involve conversation, (2) a conversation about body image, (3) a conversation about health goals, and (4) a recovery period that allowed for unstructured conversation. We used a newly developed R statistical package (i.e., rties; Butler and Barnard, 2019) that simplifies the use of dynamic models for investigating interpersonal emotional processes. We identified two different PL patterns: (1) a simple one that was characterized by stable synchronization and low frequency of oscillation; and (2) a complex one that was characterized by drifting synchronization, high frequency of oscillation, and eventual damping. Guided by social baseline theory and the reactive flexibility perspective, we explored the interactions between couple relationship functioning (i.e., love, conflict, commitment, sexual satisfaction, and relationship length) and conversational context as predictors of the PL patterns. The results suggest that partners in well-functioning relationships and emotionally challenging situations may be especially likely to show complex PL patterns that may reflect (or support) coregulatory processes.

Emotional Empathy in the Social Regulation of Distress: A Dyadic Approach

Although research suggests distressed individuals benefit from others' empathy, it is unclear how an individual's level of empathy influences dyadic responses during emotional situations. In the current study, female participants (N = 140; 70 dyads) were paired with a stranger. One member of each dyad (the experiencer) was randomly assigned to undergo a stressful task and disclose negative personal experiences to their partner (the listener). Experiencers paired with listeners higher in dispositional emotional empathy had less negative affect during emotional disclosure and lower sympathetic nervous system reactivity during the stressful task and disclosure. Listeners higher in emotional empathy reported more negative affect in response to their partner's distress. Furthermore, for listeners higher in emotional empathy, those who more accurately rated their partner's emotions were more physiologically influenced by their partners. Findings shed light on interpersonal functions of empathy and suggest a stranger's level of emotional empathy regulates distressed partner's emotions and physiology.

Pupil mimicry promotes trust through the theory-of-mind network

The human eye can provide powerful insights into the emotions and intentions of others; however, how pupillary changes influence observers' behavior remains largely unknown. The present fMRI-pupillometry study revealed that when the pupils of interacting partners synchronously dilate, trust is promoted, which suggests that pupil mimicry affiliates people. Here we provide evidence that pupil mimicry modulates trust decisions through the activation of the theory-of-mind network (precuneus, temporo-parietal junction, superior temporal sulcus, and medial prefrontal cortex). This network was recruited during pupil-dilation mimicry compared with interactions without mimicry or compared with pupil-constriction mimicry. Furthermore, the level of theory-of-mind engagement was proportional to individual's susceptibility to pupil-dilation mimicry. These data reveal a fundamental mechanism by which an individual's pupils trigger neurophysiological responses within an observer: when interacting partners synchronously dilate their pupils, humans come to feel reflections of the inner states of others, which fosters trust formation.

State of the Art of Interpersonal Physiology in Psychotherapy: A Systematic Review

Introduction: The fast expanding field of Interpersonal Physiology (IP) focuses on the study of co-ordination or synchronization dynamics between the physiological activities of two, or more, individuals. IP has been associated with various relational features (e.g., empathy, attachment security, rapport, closeness…) that overlap with desirable characteristics of clinical relationships, suggesting that the relevant studies might provide objective, economical, and theory-free techniques to investigate the clinical process. The goal of the present work is to systematically retrieve and review the literature on IP in the field of psychotherapy and psychological intervention, in order to consolidate the knowledge of this research domain, highlight its critical issues, and delineate possible developments.

Method: Following the guidelines by Okoli and Schabram (2010), a systematic literature search was performed in Scopus, Web of Science, PsycINFO, and PubMed databases by means of multiple keyword combinations; the results were integrated with references to the retrieved articles' bibliography as well as to other published reviews on IP.

Results: All the retrieved documents reported clinical interactions that are characterized, at least partially, by IP phenomena. They appear to use fragmented and sometimes ambiguous terminology and show a lack of both specific theory-informed hypotheses and sound analytical procedures.

Conclusion: Although the psychological nature of IP and its role in the clinical relationship are still mostly unknown, the potential value of a physiology-based measure of implicit exchanges in psychotherapy drives an acceleration in this research field. On the basis of the highlighted critical issues, possible future directions for clinical IP researchers are discussed.

Contagious Anxiety: Anxious European Americans Can Transmit Their Physiological Reactivity to African Americans

During interracial encounters, well-intentioned European Americans sometimes engage in subtle displays of anxiety, which can be interpreted as signs of racial bias by African American partners. In the present research, same-race and cross-race stranger dyads ( N = 123) engaged in getting-acquainted tasks, during which measures of sympathetic nervous system responses (preejection period, PEP) and heart rate variability were continuously collected. PEP scores showed that African American partners had stronger physiological linkage to European American partners who evidenced greater anxiety-greater cortisol reactivity, behavioral tension, and self-reported discomfort-which suggests greater physiological responsiveness to momentary changes in partners' affective states when those partners were anxious. European Americans showed physiological linkage to African American and European American partners, but linkage did not vary as a function of their partner's anxiety. Using physiological linkage offers a novel approach to understanding how affective responses unfold during dynamic intergroup interactions.

Intragroup Emotions: Physiological Linkage and Social Presence

We investigated how technologically mediating two different components of emotion-communicative expression and physiological state-to group members affects physiological linkage and self-reported feelings in a small group during video viewing. In different conditions the availability of second screen text chat (communicative expression) and visualization of group level physiological heart rates and their dyadic linkage (physiology) was varied. Within this four person group two participants formed a physically co-located dyad and the other two were individually situated in two separate rooms. We found that text chat always increased heart rate synchrony but HR visualization only with non-co-located dyads. We also found that physiological linkage was strongly connected to self-reported social presence. The results encourage further exploration of the possibilities of sharing group member's physiological components of emotion by technological means to enhance mediated communication and strengthen social presence.

Physiological linkage in couples and its implications for individual and interpersonal functioning: A literature review

Do partners' levels of physiological arousal become linked in close relationships? The term physiological linkage describes covariation between people in their moment-to-moment physiological states. The current review presents a conceptual framework to guide research on linkage in romantic relationships and discusses the potential implications of being linked. Evidence of linkage was found across a broad range of physiological indices and in a variety of contexts, including during laboratory-based conflict and in daily life. Four hypotheses regarding how linkage relates to individual and interpersonal functioning are evaluated: (a) coactivation of the sympathetic nervous system or the hypothalamic-pituitary adrenal axis is "bad," (b) moderate physiological linkage is "just right," (c) physiological linkage is problematic if the individual or couple is overloaded, and (d) the implications of physiological linkage depend on the emotional context. We found partial support for the first hypothesis and determined that more research is needed to evaluate the remaining hypotheses. Linkage in cortisol was negatively associated with relationship satisfaction; but, at the same time, linkage in multiple systems was positively associated with indices of relationship connectedness, such as the amount of time spent together and the ability to identify the emotions of one's partner. These results suggest that linkage may confer benefits but also may put couples at risk if they become entrenched in patterns of conflict or stress. With research in this area burgeoning in recent years, this review indicates that linkage is a promising construct with applications for interventions targeting individual health and couple functioning.