The association between an oxytocin receptor gene polymorphism and cultural orientations

The oxytocinergic system and racial ingroup bias in empathic neural activity

Studies have indicated that the human brain exhibits a more robust neural empathic response towards individuals of the same racial ingroup than those of the outgroup. However, the impact of the oxytocinergic system on the dynamic connectivity between brain regions involved in racial ingroup bias in empathy (RIBE) and its implications for real-life social interaction intention remains unclear. To address this gap, we employed functional magnetic resonance imaging (fMRI) to investigate RIBE-modulated neural activities and the influence of the oxytocinergic system at both neural and behavioral levels. Participants homozygous for the A/A and G/G genotypes of the oxytocin receptor gene (OXTR) rs53576 polymorphism underwent scanning while making judgments about painful versus non-painful stimuli in same-race versus other-race scenarios following either oxytocin (OT) or placebo treatment. The results revealed greater activity in the anterior cingulate cortex (ACC) and anterior insula (AI) in response to same-race compared to other-race models in the G/G group but not in the A/A group. RIBE also modulated the connections between bilateral AI and the ACC, and the effect of OT on this modulatory effect was moderated by genotype rs53576 and interpersonal trust. Moreover, more extensive changes in AI-ACC connections were associated with higher levels of revenge intention in the low interpersonal trust group. Overall, our findings suggest a pivotal role of the oxytocinergic system in the RIBE-modulated neural activities and revenge intention in human interactions with the modulatory effect of interpersonal trust. This article is part of the Special Issue on "Empathic Pain".

Of Germs and Culture; Parasite Stress as the Origin of Individualism-Collectivism

Among four proposed origins of individualism-collectivism, modernization theory, rice versus wheat theory, climato-economic theory, and pathogen stress theory, the latter has gained more attention in cross-cultural and evolutionary psychology. Since the parasite stress theory of values and sociality makes a connection between infectious diseases and cultural orientations, it gained even more popularity during the COVID pandemic. But despite extensive research on parasite stress theory, it is not still clear what kind of infectious disease contributes more to the emergence of cultures, what are the possible mechanisms through which pathogenic threat gives rise to cultural systems, and how parasite stress might affect vertical vs. horizontal dimensions of individualism-collectivism. This review summarizes and integrates major findings of parasite stress theory related to individualism-collectivism and its closely related variables and discusses future directions that researchers can take to answer the remaining questions.

Models of gene-culture evolution are incomplete without incorporating epigenetic effects

Epigenetics impacts gene-culture coevolution by amplifying phenotypic variation, including clustering, and bridging the difference in timescales between genetic and cultural evolution. The dual inheritance model described by Uchiyama et al. could be modified to provide greater explanatory power by incorporating epigenetic effects.

Gene-Environment Interactions in Face Categorization: Oxytocin Receptor Genotype x Childcare Experience Shortens Reaction Time

Human faces capture attention, provide information about group belonging, and elicit automatic prepared responses. Early experiences with other-race faces play a critical role in acquiring face expertise, but the exact mechanism through which early experience exerts its influence is still to be elucidated. Genetic factors and a multi-ethnic context are likely involved, but their specific influences have not been explored. This study investigated how oxytocin receptor gene (OXTR) genotypes and childcare experience interacted to regulate face categorization in adults. Information about single nucleotide polymorphisms of OXTR (rs53576) and experiences with own- and other-race child caregivers was collected from 89 Singaporean adults, who completed a visual categorization task with own- versus other-race faces. Participants were grouped into A/A homozygotes and G carriers and assigned a score to account for their type of child caregiver experience. A multivariate linear regression model was used to estimate the effect of genetic group, child caregiver experience, and their interaction on categorization reaction time. A significant interaction of genetic group and child caregiver experience (t = 2.48, p = 0.015), as well as main effects of both genetic group (t = −2.17, p = 0.033) and child caregiver experience (t = −4.29, p < 0.001) emerged. Post-hoc analysis revealed that the correlation between categorization reaction time and child caregiver experience was significantly different between the two genetic groups. A significant gene x environment interaction on face categorization appears to represent an indirect pathway through which genes and experiences interact to shape mature social sensitivity to faces in human adults.

The Interaction Effect of Parental Rejection and Oxytocin Receptor Gene Polymorphism on Depression: A Cross-Cultural Study in Non-Clinical Samples

Parental rejection has been consistently empirically implicated in a wide array of developmental, behavioural and psychological problems worldwide. However, the interaction effect between parental rejection in childhood and the oxytocin receptor genotype on psychological adjustment has yet to be investigated. The present study aimed to investigate gene–environment interaction effects between parental rejection (maternal and paternal) and oxytocin receptor (OXTR) gene polymorphisms (rs53576 and rs2254298) on depressive symptoms in adults in different cultural contexts. Adults from Italy and Japan (N = 133, age = 18–27 years, females = 68) were preliminarily genotyped and then completed the Parental Acceptance-Rejection Questionnaire for mothers and fathers and the Beck Depression Inventory. Hierarchical multiple regression analysis showed that paternal rejection was related to self-reported depression and that the effect of parental rejection was moderated by OXTR gene polymorphisms and nationality. Among Italians, OXTR rs2254298 A-carriers showed resilience to negative early parental care, whereas among Japanese, OXTR rs53576 non-A-carriers showed resistance to negative early paternal care. These findings align with expected relations between perceived acceptance–rejection and an individual’s psychological adjustment, as proposed by interpersonal acceptance–rejection theory, and indicate the need for future studies adopting a multicultural and multilevel approach to better understand how the effects of parental rejection extend into adulthood.

Exploring gene-culture coevolution in humans by inferring neuroendophenotypes: A case study of the oxytocin receptor gene and cultural tightness

The gene-culture coevolution (GCC) framework has gained increasing prominence in the social and biological sciences. While most studies on human GCC concern the evolution of low-level physiological traits, attempts have also been made to apply GCC to complex human traits, including social behavior and cognition. One major methodological challenge in this endeavor is to reconstruct a specific biological pathway between the implicated genes and their distal phenotypes. Here, we introduce a novel approach that combines data on population genetics and expression quantitative trait loci to infer the specific intermediate phenotypes of genes in the brain. We suggest that such "neuroendophenotypes" will provide more detailed mechanistic insights into the GCC process. We present a case study where we explored a GCC dynamics between the oxytocin receptor gene (OXTR) and cultural tightness-looseness. By combining data from the 1000 Genomes project and the Gene-Tissue-Expression project (GTEx), we estimated and compared OXTR expression in 10 brain regions across five human superpopulations. We found that OXTR expression in the anterior cingulate cortex (ACC) was highly variable across populations, and this variation correlated with cultural tightness and socio-ecological threats worldwide. The mediation models also suggested possible GCC dynamics where the increased OXTR expression in the ACC mediates or emerges from the tight culture and higher socio-ecological threats. Formal selection scans further confirmed that OXTR alleles linked to enhanced receptor expression in the ACC underwent positive selection in East Asian countries with tighter social norms. We discuss the implications of our method in human GCC research.

The relation between oxytocin receptor gene polymorphisms, adult attachment and Instagram sociability: An exploratory analysis

Oxytocin is a primary neuropeptide which coordinates affiliative behavior. Previous researchers pointed to the association between genetic vulnerability on Oxytocin Receptor Gene (OXTR) and environmental factors (e.g., social relationships) to comprehend social behavior. Although an extensive knowledge of in-person social interactions has been obtained, little is known about online sociability. A gene-environment perspective is adopted to examine how OXTR and adult attachment moderate Instagram behavior. The genetic factors within the regions OXTR/rs53576 (A/A homozygotes vs G-carriers) and OXTR/rs2254298 (G/G homozygotes vs A-carriers) were assessed. The Experience in Close Relationships-Revised (ECR-R) questionnaire was used to collect participants' (N = 57, 16 males) attachment with a partner. The number of posts, followed people ("followings") and followers were obtained from Instagram, and the Social Desirability Index (SDI) was calculated as the ratio of followers to followings. Interaction effects between OXTR groups and ECR-R scores on the number of posts and SDI were hypothesized. Results showed an effect of rs53576 on the number of Instagram followings. Specifically, people with A/A OXTR/rs53576 genotype had more followings than G-carriers independent of the anxiety or avoidance felt towards their partner. These preliminary results offer insights into future investigations on social media behavior.

Intranasal oxytocin decreases self-oriented learning

RATIONALE

Oxytocin has been found to play an important role in human social cognition and social interaction. Over the last two decades, surge studies have been conducted to investigate how oxytocin impacts other-oriented processes, such as trust and generosity (Zak et al. in PLoS ONE 2(11):e1128, 2007); however, the examination of the effect of oxytocin on self-related processes was relatively inadequate. Appropriate and efficient social interactions require both self- and other-related information processing. Recent studies have found that intranasal oxytocin (IN-OT) influences the self-related process, although the results have been mixed. The computational process underlying the effects of IN-OT on self-processing remains unknown.

OBJECTIVES

We aim to investigate the effect of IN-OT on self-oriented learning across different contexts (self-other independent vs. self-other dependent) and uncover the process by which IN-OT affects dynamic behavior changes.

METHODS

We performed two double-blind, placebo-controlled studies and used reinforcement learning theory to integrate action and related feedback for participants' behaviors.

RESULTS

In study 1, IN-OT decreased self-oriented reward learning when self-oriented learning and prosocial (other-oriented) learning were assessed separately. These effects were partially due to the OT-related increase in choice variability during self-oriented learning. In study 2, IN-OT also decreased learning performance during self-oriented reward learning when self-related and other-related rewards were present together. These effects occurred at an early stage of the learning process and could be moderated by the participants' social value orientation. Our findings show that OT attenuates the process of self-oriented learning and provides an underlying computational process.

CONCLUSIONS

Our findings shed new light on the dynamics of IN-OT's effects on human self-oriented learning processes. For future studies on OT effects on self-oriented learning, individual factors such as social value orientation should be taken into consideration in research development and analysis.

Oxytocin Receptor Gene (OXTR) and Childhood Adversity Influence Trust

Early-life environments have been associated with various social behaviors, including trust, in late adolescence and adulthood. Given that the oxytocin receptor gene polymorphism (OXTR rs53576) moderates the impact of childhood experience on social behaviors, in the present study, we examined the main effect of childhood adversity through a self-report measure and its interactions with OXTR rs53576 on general trust among 203 Japanese and 200 European Canadian undergraduate students. After controlling for the effect of culture, the results indicated that childhood adversity had a negative association with general trust, and that OXTR rs53576 moderated the impact of childhood adversity on general trust. Specifically, the negative association between childhood adversity and general trust is only significant among homozygote A-allele carriers. These findings demonstrated that OXTR rs53576 moderated the relations between childhood experiences and social functioning in early adulthood.

Resting-state brain network properties mediate the association between the oxytocin receptor gene and interdependence

While an increasing number of behavioral findings have provided gene-culture coevolution accounts of human development, whether and how the brain mediates gene-culture associations remain unresolved. Based on the Culture-Behavior-Brain-Loop Model and the recent finding of associations between the oxytocin receptor gene (OXTR, rs53576) and a cultural trait (i.e., interdependence) across populations, we tested the hypothesis that resting-state brain network properties mediate the relationship between OXTR rs53576 and interdependence. G and A allele carriers of OXTR rs53576 were scanned during a resting state using functional magnetic resonance imaging (fMRI) and completed questionnaires to estimate their interdependence cultural values. We identified significant genotype effects on the local network metrics of the right hippocampus and its functional connectivity with the medial prefrontal cortex, dorsal anterior cingulate cortex, amygdala, basal ganglia and thalamus. The local network metrics of the right hippocampus and its functional connectivity with the basal ganglia and thalamus were correlated with interdependence. Moreover, both the degree of the right hippocampus and its functional connectivity with the basal ganglia and thalamus mediated the relationship between OXTR and interdependence. Our results provide brain imaging evidence for a key function of the brain in mediating the relationship between genes and culture.

Association of oxytocin levels and oxytocin receptor gene polymorphism (rs2254298) with cardiovascular risk factors in Brazilian elderly from Primary Health Care

BACKGROUND

Morbidity and mortality from cardiovascular disease is a typical phenomenon in the elderly, and are related to unfavorable genetic, hormonal and environmental (lifestyle) interactions. In this context, oxytocin (OT) seems plays a key role in the development of CVD by performing important actions in metabolism energy and hemodynamic variables.

OBJECTIVE

To verify if there is an association between (OT) levels and the oxytocin receptor gene (OXTR) polymorphism (rs2254298) with cardiovascular risk factors (CRF) in the elderly.

METHODS

This was a cross-sectional study in community-dwelling elderly attending primary health care. The genotyping was done using the polymerase chain reaction technique. The CRF factors investigated included hypertension, diabetes mellitus, dyslipidemia, sedentary lifestyle, and obesity. Levels of triglycerides (TGC) postprandial and glucose were measured in capillary blood. OT and cortisol levels were measured by enzyme-linked immunosorbent assay (ELISA).

RESULTS

The sample comprised 177 elderly individuals. OT levels showed a significant negative correlation with postprandial triglycerides (p = 0.030) and BMI (p = 0.019). OT levels were also associated with leanness (p = 0.005). On Poisson regression analysis, OT remained a predictor for leanness (p = 0.010). No significant associations were observed between the OXTR polymorphism and CRF.

CONCLUSION

The results suggest that Postprandial TGC levels are increased, while OT levels are decreased, and this hormone was significantly elevated in lean elderly. Future studies are needed to confirm these findings, and the role of OT in metabolic parameters.

Cross-Cultural Affective Neuroscience

Panksepp, the father of Affective Neuroscience, dedicated his life to demonstrate that foundations of mental life and consciousness lay in the archaic layers of the brain. He had an evolutionary perspective emphasizing that the subcortical affective systems come prior to cortical cognitive systems. Based on his life-long work, the Affective Neuroscience Personality Scales (ANPS) was constructed, and a new neurodevelopmental approach to personality was started. The new approach suggested that personality was formed based on the strengths and/or weaknesses found in the subcortical basic affective systems, which are initially regulated by the mother-infant attachment styles and later by early life experiences. ANPS measured six basic affects: CARE, PLAY, SEEK, SADNESS, FEAR, and ANGER; along with a Spirituality subscale. Up to date, it has been translated to several languages, and these studies confirmed that ANPS is a reliable and valid tool. Based on the observation that these ANPS studies have both universal and culturally specific findings, cross-cultural affective neuroscience (CAN) was initiated in 2012, with the approval of Panksepp. As a new research field, CAN aims to investigate the influence of culture on the regulation of basic affective systems. CAN claims that this influence can be studied by observing the cultural variations in (1) the level of emotional interdependency, (2) the types of reinforced or suppressed affects, and (3) the types of affects that accompany interdependent or independent self-construals. Cross-cultural comparisons of Turkish and American ANPS findings and the results of our first Euro-Asian CAN project among Japan, Turkey, and Germany support these claims. These cultures regulate the basic affective systems in unique ways, while maintaining certain similarities with each other. In a way, each culture has a unique affective personality profile and a specific function in the global affective network. The conclusion of this review shares guidelines, suggestions and ethical codes for future CAN researches.

Children's Relationship With Their Pet Dogs and OXTR Genotype Predict Child-Pet Interaction in an Experimental Setting

Human-animal interaction (HAI) research has increasingly documented the important role of pet dogs in children's lives. The quality of interaction between children and their pet dogs, however, is likely influenced by individual differences among children as well as their perceived relationship with their pet dog. Ninety-seven children aged 7-12 years and their pet dogs participated in a laboratory protocol during which the child solicited interaction with their dog, from which time petting and gazing were recorded. Children reported on their perceived relationship with the pet dog via interview. Children provided saliva samples, from which a polymorphism in the oxytocin receptor, OXTR rs53576, which has long been implicated in social behavior, was genotyped. The results showed that OXTR genotype and children's perceived antagonism with the pet dog predicted the amount of petting, but not gazing, between children and their pet dogs. This research adds to the growing body of HAI research by documenting individual differences that may influence children's interactions with animals, which is key to research related to pet ownership and understanding factors that may impact therapeutic interventions involving HAI.

Transactions Between Substance Use Intervention, the Oxytocin Receptor (OXTR) Gene, and Peer Substance Use Predicting Youth Alcohol Use

This study investigated the oxytocin receptor (OXTR) gene's moderation of associations between exposure to a substance misuse intervention, average peer substance use, and adolescents' own alcohol use during the 9th-grade. OXTR genetic risk was measured using five single nucleotide polymorphisms (SNPs), and peer substance use was based on youths' nominated closest friends' own reports of alcohol, cigarette, and marijuana use, based on data from the PROSPER project. Regression models revealed several findings. First, low OXTR risk was linked to affiliating with friends who reported less substance use in the intervention condition but not the control condition. Second, affiliating with high substance-using friends predicted youth alcohol risk regardless of OXTR risk or intervention condition. Third, although high OXTR risk youth in the intervention condition who associated with low substance-using friends reported somewhat higher alcohol use than comparable youth in the control group, the absolute level of alcohol use among these youth was still among the lowest in the sample.

Associations between the oxytocin receptor gene (OXTR) rs53576 polymorphism and emotional processing of social and nonsocial cues: an event-related potential (ERP) study

Background

Oxytocin receptor (OXTR) gene polymorphisms are related to individual differences in emotional processing of social cues. However, whether OXTR polymorphisms affect emotional processing of nonsocial cues remains unclear. The present study investigated the relationship between the OXTR rs53576 polymorphism and emotional processing of social cues and nonsocial cues.

Methods

Event-related potentials were recorded from 88 male participants while images of humans and images of objects were presented as social cues and nonsocial cues, respectively.

Results

First, the results showed that GG carriers of OXTR rs53576 showed more negative N1 (50–200 ms) than AA carriers in response to images of both humans and objects. Second, GG carriers showed more negative N2 (200–320 ms) than AA carriers in response to images of humans but not in response to images of objects. Third, GG carriers showed more negative N2 in response to images of humans than images of objects, whereas AA carriers showed the opposite pattern. Fourth, we observed no difference in late positive potential (600–1000 ms) to images of humans or objects that depended on the OXTR rs53576 polymorphism.

Conclusions

These results suggest that the OXTR rs53576 polymorphism affects emotional processing of not only social cues but also nonsocial cues in the very early stage (reflected in N1); however, the data also suggest that the OXTR rs53576 polymorphism is related specifically to increased emotional processing of social cues in the middle stage (reflected in N2).

Polymorphisms of two loci at the oxytocin receptor gene in populations of Africa, Asia and South Europe

Background

The oxytocin (OT) system is known to be implicated in the regulation of complex social behavior, particularly empathy and parenting. The goal of this study was to estimate the gender and population differences in polymorphisms of two oxytocin receptor gene SNPs, rs53576 and rs2254298, in four populations.

Results

These data were compared with each other and with 14 samples from the corresponding regions retrieved from the 1000 Genomes database. Low level of heterozygosity was observed for both SNPs in all populations in this study (rs53576: Catalonian, Hobs = 0.413; Hadza, Hobs = 0.556; sr2254698: Khanty-Mansi, Hobs = 0.250; Datoga, Hobs = 0.550). The amount of variance due to regional variability was almost equal for both SNPs (rs53576: F_RT = 0.086, rs2554298: F_RT = 0.072), whereas variance for the population level of variability was twice bigger for rs2554298 (rs53576: F_ST = 0.127, rs2554298: F_ST = 0.162). Pairwise coefficients of fixation demonstrate that the Hadza were well differentiated from other African populations except of Datoga, the Datoga were weakly differentiated from other African origin populations, the Ob Ugric people were extremely differentiated from all other populations. Catalans were extremely differentiated of Asian populations.

Conclusions

It is hypothesized on the base of spatial distribution of the evolutionary novel A alleles of the both OXTR gene loci, that the spread of alleles of rs22542298 and rs53376 SNPs may be associated to some extant with manipulation of parental investment in humans.

Electronic supplementary material

The online version of this article (doi:10.1186/s12863-015-0323-8) contains supplementary material, which is available to authorized users.

Interaction between oxytocin receptor polymorphism and interdependent culture values on human empathy

Recent evidence suggests that the association between oxytocin receptor polymorphism (OXTR rs53576) and emotion-related behavioral/psychological tendencies differs between individuals from East Asian and Western cultures. What remains unresolved is which specific dimension of cultural orientations interacts with OXTR rs53576 to shape these tendencies and whether such gene × culture interactions occurs at both behavioral and neural level. This study investigated whether and how OXTR rs53576 interacts with interdependence-a key dimension of cultural orientations that distinguish between East Asian and Western cultures-to affect human empathy that underlies altruistic motivation and prosocial behavior. Experiment 1 measured interdependence, empathy trait and OXTR rs53576 genotypes of 1536 Chinese participants. Hierarchical regression analyses revealed a stronger association between interdependence and empathy trait in G allele carriers compared with A/A homozygotes of OXTR rs53576. Experiment 2 measured neural responses to others' suffering by scanning A/A and G/G homozygous of OXTR rs53576 using functional magnetic resonance imaging. Hierarchical regression analyses revealed stronger associations between interdependence and empathic neural responses in the insula, amygdala and superior temporal gyrus in G/G compared with A/A carriers. Our results provide the first evidence for gene × culture interactions on empathy at both behavioral tendency and underlying brain activity.

Cultural differences in human brain activity: a quantitative meta-analysis

Psychologists have been trying to understand differences in cognition and behavior between East Asian and Western cultures within a single cognitive framework such as holistic versus analytic or interdependent versus independent processes. However, it remains unclear whether cultural differences in multiple psychological processes correspond to the same or different neural networks. We conducted a quantitative meta-analysis of 35 functional MRI studies to examine cultural differences in brain activity engaged in social and non-social processes. We showed that social cognitive processes are characterized by stronger activity in the dorsal medial prefrontal cortex, lateral frontal cortex and temporoparietal junction in East Asians but stronger activity in the anterior cingulate, ventral medial prefrontal cortex and bilateral insula in Westerners. Social affective processes are associated with stronger activity in the right dorsal lateral frontal cortex in East Asians but greater activity in the left insula and right temporal pole in Westerners. Non-social processes induce stronger activity in the left inferior parietal cortex, left middle occipital and left superior parietal cortex in East Asians but greater activations in the right lingual gyrus, right inferior parietal cortex and precuneus in Westerners. The results suggest that cultural differences in social and non-social processes are mediated by distinct neural networks. Moreover, East Asian cultures are associated with increased neural activity in the brain regions related to inference of others' mind and emotion regulation whereas Western cultures are associated with enhanced neural activity in the brain areas related to self-relevance encoding and emotional responses during social cognitive/affective processes.