Oxytocin facilitation of acceptance of social advice is dependent upon the perceived trustworthiness of individual advisors

Enhanced endogenous oxytocin signaling in the brain modulates neural responses to social misalignment and promotes conformity in humans: A multi-locus genetic profile approach

The neuropeptide oxytocin (OT) is known to promote social conformity. However, the specific neurocognitive mechanisms underlying OT-induced conformity remain unclear. We aimed to address this gap by examining how genetic variation in the oxytocin receptor gene (OXTR) is linked with behavioral conformity and its underlying neural systems. Specifically, we utilized the genotype-tissue expression database (GTEx) to create a novel multi-locus genetic profile score (MPS) that reflects the level of OXTR expression in the human brain. A total of 194 participants (Neuroimaging N = 50, Behavioral N = 144) performed a novel conformity task in which they viewed a series of word pairs depicting various moral values and virtues widely recognized in the United States. In each trial, participants indicated the relative importance of these words and subsequently learned about the majority opinion. Participants later rated the same word pairs a second time. Changes in participants' ratings between the first and second sessions were measured and analyzed with respect to social feedback, blood oxygen level-dependent (BOLD) functional magnetic resonance imaging (fMRI) signals, and OXTR MPS. We found that participants adjusted their ratings in accordance with the majority opinions. Social misalignment between self and others activated brain areas such as the striatum and the posterior medial frontal cortex (pMFC). However, unlike most findings from previous studies, activation in the pMFC during the inconsistent social feedback negatively, rather than positively, predicted behavioral conformity. Notably, those with higher OXTR MPS had reduced pMFC activation in the face of social misalignment, which led to greater conformity. Our findings suggest that OT may promote conformity by dampening the conflict-related signals in the pMFC. They also show that OXTR MPS may be useful for studying the effect of genes on highly complex human social traits, such as conformity.

Oxytocin and the social facilitation of placebo effects

Significant clinical improvement is often observed in patients who receive placebo treatment in randomized double-blind placebo-controlled trials. While a proportion of this "improvement" reflects experimental design limitations (e.g., reliance on subjective outcomes, unbalanced groups, reporting biases), some of it reflects genuine improvement corroborated by physiological change. Converging evidence across diverse medical conditions suggests that clinically-relevant benefits from placebo treatment are associated with the activation of brain reward circuits. In parallel, evidence has accumulated showing that such benefits are facilitated by clinicians that demonstrate warmth and proficiency during interactions with patients. Here, we integrate research on these neural and social aspects of placebo effects with evidence linking oxytocin and social reward to advance a neurobiological account for the social facilitation of placebo effects. This account frames oxytocin as a key mediator of treatment success across a wide-spectrum of interventions that increase social connectedness, thereby providing a biological basis for assessing this fundamental non-specific element of medical care.

Oxytocin moderates the association between testosterone-cortisol ratio and trustworthiness: A randomized placebo-controlled study

Oxytocin has been proposed to enhance feelings of trust, however, these findings have been difficult to replicate. Environmental or hormonal factors might influence this association. We studied whether oxytocin moderates the association between the testosterone-cortisol ratio, which is associated with risk taking behavior and aggression, and trustworthiness, while controlling for the general level of trust. A randomized double-blind placebo-controlled study with 53 healthy males was performed in which 32IU oxytocin (n = 27) or placebo (n = 26) was administered intranasally. Participants subsequently played the Trust Game in which they were allocated to the role of trustee. In the third phase of the Trust Game, we found a positive association between the testosterone-cortisol-ratio and the proportion of the amount that is returned to the investor (P=<0.01). However, administration of oxytocin reduced reciprocity in those with a high testosterone-cortisol ratio after reciprocity restoration (a significant interaction effect between administration of oxytocin and the testosterone-cortisol ratio in the third phase of the Trust Game, P = 0.015). The third phase of the Trust Game represents the restoration of reciprocity and trustworthiness, after this is violated in the second phase. Therefore, our data suggest that oxytocin might hinder the restoration of trustworthiness and diminish risk-taking behavior when trust is violated, especially in those who are hormonally prone to risk-taking behavior by a high testosterone-cortisol ratio.

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Oxytocin (32IU) was administered intranasally to healthy young males in a double-blind placebo-controlled study.

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Testosterone-cortisol ratio was positively associated with trustworthiness during the Trust Game.

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Oxytocin significantly attenuated the association between testosterone-cortisol ratio and trustworthiness.

Intranasal vasopressin like oxytocin increases social attention by influencing top-down control, but additionally enhances bottom-up control

The respective roles of the neuropeptides arginine vasopressin (AVP) and oxytocin (OXT) in modulating social cognition and for therapeutic intervention in autism spectrum disorder have not been fully established. In particular, while numerous studies have demonstrated effects of oxytocin in promoting social attention the role of AVP has not been examined. The present study employed a randomized, double-blind, placebo (PLC)-controlled between-subject design to explore the social- and emotion-specific effects of AVP on both bottom-up and top-down attention processing with a validated emotional anti-saccade eye-tracking paradigm in 80 healthy male subjects (PLC = 40, AVP = 40). Our findings showed that AVP increased the error rate for social (angry, fearful, happy, neutral and sad faces) but not non-social (oval shapes) stimuli during the anti-saccade condition and reduced error rates in the pro-saccade condition. Comparison of these findings with a previous study (sample size: PLC = 33, OXT = 33) using intranasal oxytocin revealed similar effects of the two peptides on anti-saccade errors, although with some difference in effects of specific face emotions, but a significantly greater effect of AVP on pro-saccades. Both peptides also produced a post-task anxiolytic effect by reducing state anxiety. Together these findings suggested that both AVP and OXT decrease goal-directed top-down attention control to social salient stimuli but that AVP more potently increased bottom-up social attentional processing.

Intranasal oxytocin may help maintain romantic bonds by decreasing jealousy evoked by either imagined or real partner infidelity

BACKGROUND

While romantic jealousy may help to maintain relationships, following partner infidelity and an irretrievable loss of trust it can also promote break-ups. The neuropeptide oxytocin can enhance the maintenance of social bonds and reduce couple conflict, although its influence on jealousy evoked by imagined or real infidelity is unclear.

AIMS

This study aimed to investigate the effects of intranasal oxytocin (24 IU) on romantic jealousy in both males and females in imagined and real contexts.

METHODS

Seventy heterosexual couples participated in this double-blind, placebo-controlled, between-subject design study. Jealousy was firstly quantified in the context of subjects imagining partner infidelity and secondly in a Cyberball game where their partner interacted preferentially with an opposite-sexed rival stranger to simulate partner exclusion, or rejected a neutral stranger but not the partner.

RESULTS

Oxytocin primarily decreased jealousy and arousal ratings towards imagined emotional and sexual infidelity by a partner in both sexes. During the Cyberball game, while male and female subjects in both groups subsequently threw the ball least often to the rival stranger, under oxytocin they showed reduced romantic jealousy and arousal ratings for stranger players, particularly the rival one, and reported reduced negative and increased positive feelings while playing the game.

CONCLUSIONS

Together, our results suggest that oxytocin can reduce the negative emotional impact of jealousy in established romantic partners evoked by imagined or real infidelity or exclusive social interactions with others. This provides further support for oxytocin promoting maintenance of relationships.

Oxytocin amplifies sex differences in human mate choice

Infidelity is the major cause of breakups and individuals with a history of infidelity are more likely to repeat it, but may also present a greater opportunity for short-term sexual relationships. Here in a pre-registered, double-blind study involving 160 subjects we report that while both sexes valued faithful individuals most for short-term and long-term relationships, both single men and those in a relationship were more interested in having short-term relationships with previously unfaithful individuals than women. Oxytocin administration resulted in men rating the faces of unfaithful women as more attractive and likeable but in women rating those of unfaithful men as less attractive and also finding them less memorable. Oxytocin also increased single men's interest in having short-term relationships with previously unfaithful women whereas it increased single women's interest in having long-term relationships with faithful men. Thus, oxytocin release during courtship may first act to amplify sex-dependent priorities in attraction and mate choice before subsequently promoting romantic bonds.

Trust, Sexual Trust, and Sexual Health: An Interrogative Review

Trust is experienced almost constantly in all forms of social and interpersonal relationships, including sexual relationships, and may contribute both directly and indirectly to sexual health. The purpose of this review is to link three aspects of trust to sexual health: (1) the role of trust in sexual relationships; (2) the role of trust in sexually transmitted infection (STI) prevention, particularly condom use; and (3) the relevance of trust in sexual relationships outside of the traditional model of monogamy. The review ends with consideration of perspectives that could guide new research toward understanding the enigmas of trust in partnered sexual relations in the context of sexual and public health.

Oxytocin Facilitates Social Learning by Promoting Conformity to Trusted Individuals

There is considerable interest in the role of the neuropeptide oxytocin in promoting social cohesion both in terms of promoting specific social bonds and also more generally for increasing our willingness to trust others and/or to conform to their opinions. These latter findings may also be important in the context of a modulatory role for oxytocin in improving the efficacy of behavioral therapy in psychiatric disorders. However, the original landmark studies claiming an important role for oxytocin in enhancing trust in others, primarily using economic game strategies, have been questioned by subsequent meta-analytic approaches or failure to reproduce findings in different contexts. On the other hand, a growing number of studies have consistently reported that oxytocin promotes conformity to the views of groups of in-group individuals. Most recently we have found that oxytocin can increase acceptance of social advice given by individual experts without influencing their perceived trustworthiness per se, but that increased conformity in this context is associated with how much an expert is initially trusted and liked. Oxytocin can also enhance the impact of information given by experts by facilitating expectancy and placebo effects. Here we therefore propose that a key role for oxytocin is not in facilitating social trust per se but in conforming to, and learning from, trusted individuals who are either in-group members and/or perceived experts. The implications of this for social learning and use of oxytocin as an adjunct to behavioral therapy in psychiatric disorders are discussed. Interpersonal trust within social groups is of key importance for social interactions, bonds, cooperation and learning and trust between different groups can also help ensure a stable and peaceful co-existence as well as mutually beneficial co-operation and trade. Trust is generally considered to be critical for co-operation and reciprocity in social and economic interactions but importantly trust also involves risk of potential injury if misplaced or broken and we have a natural aversion to taking such risks (Hardin, 2002; Ostrom and Walker, 2003). Indeed, an important factor influencing our trust behavior is that we are strongly motivated to avoid others betraying our trust (Bohnet and Zeckhauser, 2004; Bohnet et al., 2008). Trust can potentially be influenced by our assessment of the level of risk that trusting others might have and also by increased sensitivity to physical and/or other cues for detecting trustworthiness. It is therefore of great importance to identify both behavioral and physiological factors which can act to enhance trust, particularly in situations where individuals have impaired trust and therefore find it hard to interact socially with others and learn from them and/or to benefit optimally from cognitive and behavioral therapeutic strategies.