Blocking mu-opioid receptors inhibits social bonding in rituals

2020

A key function of religious rituals is their ability to connect or bond individuals. Recent advances on the neurobiological underpinnings of bonding, highlighting how opioids are activated in the brain by social activities, can now be applied to the study of rituals. Here we present the results of a large-scale field study conducted across the UK and Brazil where we examined the psychobiological functions of rituals, following the brain-opioid theory of social attachment (BOTSA). Testing was conducted across 24 sessions at Christian and Afro-Brazilian religious rituals (N=358), with measures taken before and after each ritual. Regression analysis and multilevel linear modelling showed that taking part in religious rituals increased both pain threshold (a proxy for opioid activation) and positive affect, and that these enhanced the sense of bonding to one’s religious group. The results suggest that one of the key functions of religious ritual is to increase community bonding.

2019

Social bonds have a profound impact on our everyday life. People differ in their capacity for establishing and maintain strong, intimate relationships. These differences are characterized as attachment styles. Particularly insecure attachment style may lead to developmental and psychiatric disorders, as well as to addictive behavior (Mikulincer & Shaver 2007), which cause large societal expenses due to treatment and sickness leaves. In addition to anti-nociception and reward, the endogenous opioid system has been proposed to regulate social bonding in mammals. That could explain the link between social distress and physical pain (Panksepp & Nelson 1997). However, the role of the endogenous opioid system in human social behavior remains poorly understood (Machin & Dunbar 2011). The aim of this thesis was to investigate opioidergic basis of affiliative behavior with positron-emission tomography (PET). We approached the phenomenon from two perspectives: by 1) measuring how prosocial be...

Frontiers in Behavioral Neuroscience, 2014

Social mammals engage in affiliative interactions both when seeking relief from negative affect and when searching for pleasure and joy. These two motivational states are both modulated by μ-opioid transmission. The μ-opioid receptor (MOR) system in the brain mediates pain relief and reward behaviors, and is implicated in social reward processing and affiliative bonding across mammalian species. However, pharmacological manipulation of the μ-opioid system has yielded opposite effects on rodents and primates: in rodents, social motivation is generally increased by MOR agonists and reduced by antagonists, whereas the opposite pattern has been shown in primates. Here, we address this paradox by taking into account differences in motivational state. We first review evidence for μ-opioid mediation of reward processing, emotion regulation, and affiliation in humans, non-human primates, rodents and other species. Based on the consistent cross-species similarities in opioid functioning, we propose a unified, state-dependent model for μ-opioid modulation of affiliation across the mammalian species. Finally, we show that this state-dependent model is supported by evidence from both rodent and primate studies, when species and age differences in social separation response are taken into account.

Social mammals engage in affiliative interactions both when seeking relief from negative affect and when searching for pleasure and joy. These two motivational states are both modulated by μ-opioid transmission. The μ-opioid receptor (MOR) system in the brain mediates pain relief and reward behaviors, and is implicated in social reward processing and affiliative bonding across mammalian species. However, pharmacological manipulation of the μ-opioid system has yielded opposite effects on rodents and primates: in rodents, social motivation is generally increased by MOR agonists and reduced by antagonists, whereas the opposite pattern has been shown in primates. Here, we address this paradox by taking into account differences in motivational state. We first review evidence for μ-opioid mediation of reward processing, emotion regulation, and affiliation in humans, non-human primates, rodents and other species. Based on the consistent cross-species similarities in opioid functioning, we propose a unified, state-dependent model for μ-opioid modulation of affiliation across the mammalian species. Finally, we show that this state-dependent model is supported by evidence from both rodent and primate studies, when species and age differences in social separation response are taken into account.

Neuroscience and Biobehavioral Reviews, 1980

opioids and social behavior. NEUROSCI. BIOBEHAV. REV. 4(3,) 473-487, 1980.--Evidence for the hypothesis that braln-opioids mediate social affect and social attachments is summarized. Opiates and opioids are very effective in reducing social separationinduced distress vocalizations (DVs), in puppies, young guinea pigs and chicks, while opiate antagonists can increase DVs. In studies of specific social behaviors in rodents, morphine (at doses 1 mg/kg and below) decreases proximity maintenance time in socially housed animals, increases play, decreases maternal aggression but has no effect on pup retrieval. Naloxone reduces play and disrupts pup-retrieval, but has no consistent effect on proximity maintenance time of socially housed animals. In young rats tested in social learning situations, morphine delays and naloxone hastens extinction. These data are consistent with the proposition that brain opioids modulate social emotions and behaviors.

Ethos, 1989

Pharmacology Biochemistry and Behavior, 1979

The effect of low (1 mg/kg) doses of morphine on maintenance of physical proximity were evaluated in paired rats observed in a 4 square foot test arena. Morphine reliably reduced proximity maintenance time, and this was apparently not due to sedation, since the effect was unmodified by doses of amphetamine which substantially increased motor activity. The effects of naloxone were inconsistent on this measure of social motivation. In general, the results are consistent with the theoretical proposition that a brain neurochemical change which might lead to social attraction is the activation of endogenous opioid systems. When opiate activity is exogenously sustained, animals exhibit a subnormal tendency to be gregarious.

RELIGION, BRAIN & BEHAVIOR, 2019

Rituals are thought to bind individuals together. Rituals that are perceived high in pain and behavioral synchrony increase social bonding, but the relative contribution of perceived pain vs. synchrony is unexplored. In addition, gender differences are rarely investigated in experimental studies of ritual, despite known gender differences in ritual participation, emotional processing, social bonding and pain processing. The current study uses data from 137 participants in a naturally occurring high ordeal ritual lasting 10 days. Because all individuals participated in multiple rituals varying in perceived pain and synchrony, it was possible to separate the unique and joint effects in a natural context. We found strong bonding effects for rituals perceived as painful, but not for synchrony. Rituals rated as higher in level of pain (involving cuts, piercings and burns) were associated with greater self-reported social bonding. Gender moderated these effects: Women reported stronger bonding after participating in non-synchronous rituals perceived higher in pain, whereas men reported greater bonding after synchronous activities with more perceived pain. These findings suggest that pain-related processes are a more potent social bonding mechanism than synchrony in naturally occurring high ordeal rituals, but that perceived pain may have different signaling functions depending on the gender of performers. ARTICLE HISTORY Collective rituals pose interesting questions from an evolutionary perspective, especially those rituals in which individuals voluntarily inflict pain, suffer injuries, or undergo extended periods of chanting or praying. These activities involve costs for participants that may seem to not have any immediate benefits, especially when considering the risks of injuries or involving costly taboos such as foregoing food, drink or sleep for extended periods of time. Recently, a number of studies have demonstrated that both discomfort or behavioral synchrony as specific features of collective ritual increase proso-ciality and social bonding (e.g., Xygalatas et al., 2013). Anthropolo-gical records indicate that many collective rituals involve both discomfort 1 (including states that outsiders would consider as painful) and synchrony 2 elements, with participants often singing, chanting and dancing while performing high ordeal activities (e.g., Turner, 1969; Whitehouse, 2004; Xygalatas, 2012a). Previous research has studied these effects in isolation, but most rituals vary along both dimensions. We address to what extent physical discomfort/high physical ordeal and

Behavioral and Neural Biology, 1993

The kin selection theory predicts that individuals would behave differently toward one another, depending on their genetic relatedness. Proximate mechanisms have been postulated to exist helping the individual to discriminate what is good or bad for him. Opioids have been discovered to be involved in the mediation of reinforcement, in particular they underlay social emotion. In this study it is shown that pain sensitivity decreased in male mice interacting with siblings following 2 months of separation; this analgesic response was antagonized by naloxone administration. Interaction with unknown and unrelated subjects did not change the nociceptive threshold. These results suggest that interacting with kin is an adaptive situation reinforced, at the neural level, by the release of endogenous opioids. ~ 1993 Academic Press, Inc.

Behaviour, 2011

The psychology of close human relationships is increasingly well understood and our understanding of the neurobiology of the onset of pairbonding behaviour in a range of species has benefited from the use of rodent-based models. However, the human literature has suffered from a lack of focus upon the unique nature of primate social bonds and has so far failed to adequately identify the neurobiological and behavioural mechanisms which maintain these complex, diverse and enduring social networks. One neurobiological mechanism that has been overlooked is the endogenous opioid system. Though less explicitly researched than the more familiar oxytocin/vasopressin system, there is considerable evidence that the opioids play a fundamental role in sociality, especially in the primates. This review summarises our current understanding of the evidence for the role of this system in prosocial behaviour in non-primate mammals, nonhuman primates and humans. An important conclusion is that the opi...