Boys vs. girls: Gender differences in the neural development of trust and reciprocity depend on social context

Visual analysis of trustworthiness studies: based on the Web of Science database

Trustworthiness is the most significant predictor of trust and has a significant impact on people's levels of trust. Most trustworthiness-related research is empirical, and while it has a long history, it is challenging for academics to get insights that are applicable to their fields of study and to successfully transfer fragmented results into practice. In order to grasp their dynamic development processes through the mapping of network knowledge graphs, this paper is based on the Web of Science database and uses CiteSpace (6.2.R4) software to compile and visualize the 1,463 publications on trustworthy studies over the past 10 years. This paper aims to provide valuable references to theoretical research and the practice of Trustworthiness. The findings demonstrate that: over the past 10 years, trustworthiness-related research has generally increased in volume; trustworthiness research is concentrated in industrialized Europe and America, with American research findings having a bigger global impact; The University of California System, Harvard University, and Yale University are among the high-production institutions; the leading figures are represented by Alexander Todorov, Marco Brambilla, Bastian Jaeger, and others; the core authors are distinguished university scholars; however, the level of cooperation of the core author needs to be improved. The primary journal for publishing research on trustworthiness is the Journal of Personality and Social Psychology and Biology Letters. In addition, the study focuses on three distinct domains, involving social perception, facial clues, and artificial intelligence.

Learning whom not to trust across early and middle adolescence: A longitudinal neuroimaging study to trusting behavior involving an uncooperative other

Longitudinal changes in trusting behavior across adolescence and their neural correlates were examined. Neural regions of interest (ROIs) included the medial prefrontal cortex (mPFC), dorsal anterior cingulate cortex (dACC), left anterior insula (AI), bilateral ventral striatum (VS), and right dorsal striatum (DS). Participants (wave 1 age: M = 12.90) played the investor in a Trust Game with an uncooperative trustee three times (1-year interval). Analyses included 77 primarily Dutch participants (33 females). Participants decreased their investments with wave. Furthermore, activity was heightened in mPFC, dACC, and DS during investment and repayment, and in right VS (investment) and AI (repayment). Finally, DS activity during repayment increased with wave. These findings highlight early-middle adolescence as an important period for developing sensitivity to uncooperative behavior.

Exploring gender differences in risk factors for self-harm in adolescents using data from the Millennium Cohort Study

BACKGROUND

Self-harm is common in young people and girls have consistently higher rates of self-harm than boys. Differences in exposure and reactions to risk and protective factors, adverse events and problematic interpersonal relationships, and levels of wellbeing could contribute to the gender difference. This study aims to explore gender differences in risk factors associated with self-harm, to provide the foundation for developing more gender-sensitive approaches to self-harm management.

METHODS

Data were analysed from 11,196 young people recruited to the Millennium Cohort Study, surveyed around age 14. We examined gender differences in the prevalence of key psychological and social risk factors for self-harm, including family and peer relationships, emotional wellbeing, and bullying and victimisation. We utilised modified Poisson regression to estimate gender-specific risks.

RESULTS

At age 14 self-harm prevalence was 15.4 % with a ratio of 2.6 females to 1 male. Differential exposure to recorded psychosocial risk factors explained a third of the gender difference in risk of self-harm. Intense social media use and not confiding in family members were associated with a greater likelihood of self-harm in girls than boys. Bullying others and same-sex attraction were more strongly associated with self-harm in boys than girls.

LIMITATIONS

Self-harm data were obtained by self-report therefore subject to misclassification. The cross-sectional design does not enable us to establish causation.

CONCLUSIONS

Unhappiness and dissatisfaction are common in adolescence. Our findings suggest the need for further research into young people's experiences to explore why rates differ and inform the development of gender-specific approaches to self-harm management.

Adolescents' trust and reciprocity toward friends, unknown peers, and community members

Using a newly developed version of the Trust Game among 196 adolescents aged 11-20 years, this study examined whether adolescents distinguish between trust and reciprocity to unknown peers, friends, and community members. We also tested for effects of age, gender, and individual differences in attending to others' emotions, emotional support to friends, societal contributions, and institutional and interpersonal trust beliefs. Results indicated that adolescents showed the least trust and reciprocity to unknown peers, more to a community member, and most to friends. Reciprocity increased with age, and individual differences in societal contributions and interpersonal trust were positively related to trust and reciprocity. This study was the first to show that community members are a specific target in adolescents' social world.

Neural Mechanisms Underlying Trust to Friends, Community Members, and Unknown Peers in Adolescence

Trust plays an important role during adolescence for developing social relations. Although prior developmental studies give us insight into adolescents' development of differentiation between close (e.g., friends) and unknown (e.g., unknown peers) targets in trust choices, less is known about the development of trust to societal targets (e.g., members of a community organization) and its underlying neural mechanisms. Using a modified version of the Trust Game, our preregistered fMRI study examined the underlying neural mechanisms of trust to close (friend), societal (community member), and unknown others (unknown peer) during adolescence in 106 participants (aged 12-23 years). Adolescents showed most trust to friends, less trust to community members, and the least trust to unknown peers. Neural results show that target differentiation in adolescents' trust behavior is associated with activity in social brain regions implicated during mentalizing, reward processing, and cognitive control. Recruitment of the medial prefrontal cortex (mPFC) and OFC was higher for closer targets (i.e., friend and community member). For the mPFC, this effect was most pronounced during no trust choices. Trust to friends was additionally associated with increased activity in the precuneus and bilateral temporal parietal junction. In contrast, bilateral dorsolateral prefrontal cortex and anterior cingulate cortex were most active for trust to unknown peers. The mPFC showed increased activity with age and consistent relations with individual differences in feeling needed/useful.

Self-reported childhood family adversity is linked to an attenuated gain of trust during adolescence

A longstanding proposal in developmental research is that childhood family experiences provide a template that shapes a capacity for trust-based social relationships. We leveraged longitudinal data from a cohort of healthy adolescents (n = 570, aged 14-25), which included decision-making and psychometric data, to characterise normative developmental trajectories of trust behaviour and inter-individual differences therein. Extending on previous cross-sectional findings from the same cohort, we show that a task-based measure of trust increases longitudinally from adolescence into young adulthood. Computational modelling suggests this is due to a decrease in social risk aversion. Self-reported family adversity attenuates this developmental gain in trust behaviour, and within our computational model, this relates to a higher 'irritability' parameter in those reporting greater adversity. Unconditional trust at measurement time point T1 predicts the longitudinal trajectory of self-reported peer relation quality, particularly so for those with higher family adversity, consistent with trust acting as a resilience factor.

Social network position, trust behavior, and neural activity in young adolescents

Our social interactions take place within numerous social networks, in which our relationships with others define our position within these networks. In this study, we examined how the centrality of positions within social networks was associated with trust behavior and neural activity in 49 adolescents (M_age = 12.8 years, SD_age = 0.4 years). The participants played a trust game with a cartoon animation as a partner, which showed adaptive behavior in response to the participant and was generally untrustworthy. Social network positions were obtained in secondary school classrooms where the participants and their classmates reported on who their friends were. Using social network analysis, a score was calculated that indicated the centrality of everyone's position within the friendship network. The results showed that more central social network positions were associated with higher levels of initial trust behavior, although no evidence was found for a relationship between network position and the adaptation of trust behavior. The results of the functional MRI analyses showed that the centrality of the network positions was positively associated with caudate activity when making trust decisions. Furthermore, the adolescents with more central network positions also showed stronger increases of caudate activity when the partner's return was processed compared to the adolescents with less central network positions. The current study provides initial evidence that social network positions in friendship networks relate to socio-cognitive behavior and neural activity in adolescents.

The development of adolescent trust behavior

Interpersonal trust shows developmental changes during adolescence. The current study used a longitudinal design to examine the development of trust behavior, the presence of gender differences in these developmental trajectories, and the association between individual differences in these developmental trajectories and perspective-taking abilities. The participants played a trust game with a hypothetical trustworthy partner and a trust game with a hypothetical untrustworthy partner in 3 consecutive years (M_age = 12.55 years, M_age = 13.54 years, and M_age = 14.54 years). Concerning the development of trust behavior, the results showed an age-related increase in initial trust behavior and indicated increasingly adaptive trust behavior with age during untrustworthy interactions, whereas no evidence was found for age-related changes in the adaptation of trust during trustworthy interactions. Gender differences were found for the development of initial trust behavior (with boys showing a stronger increase with age than girls), whereas no support was found for the presence of gender differences in the developmental trajectories of adaptive trust behavior during trustworthy and untrustworthy interactions. Furthermore, no evidence was found for perspective-taking abilities to explain individual differences in the development of initial trust behavior or in the development of adaptive trust behavior during trustworthy and untrustworthy interactions. The results provide evidence that, during adolescence initial trust behavior increased with age, more for boys than for girls, and that both boys and girls showed a stronger adaptive response to the untrustworthy partner but not to the trustworthy partner.

The effect of incorrect prior information on trust behavior in adolescents

During adolescence, social cognition and the brain undergo major developments. Social interactions become more important, and adolescents must learn that not everyone can be trusted equally. Prior knowledge about the trustworthiness of an interaction partner may affect adolescents' expectations about the partner. However, the expectations based on prior knowledge can turn out to be incorrect, causing the need to respond adaptively during the interaction. In the current fMRI study, we investigated the effect of incorrect prior knowledge on adolescent trust behavior and on the neural processes of trust. Thirty-three adolescents (M_age = 17.2 years, SD_age = 0.5 years) played two trust games with partners whose behavior was preprogrammed using an algorithm that modeled trustworthy behavior. Prior to the start of both games, participants received information suggesting that the partner in one game was untrustworthy (raising incorrect expectations) and the partner in the other game trustworthy (raising correct expectations). Results indicated that participants adapted their trust behavior following incorrect prior expectations. No evidence for a change in trust behavior was shown when prior expectations were correct. fMRI analyses revealed that when receiving the partner's response, activity in the dorsolateral prefrontal cortex and in the superior parietal gyrus were increased when participants had incorrect expectations about the partner compared to when participants had correct expectations. When making trust decisions, no significant differences in neural activity were found when comparing the two games. This study provides insight into how adolescent trust behavior and neural mechanisms are affected by expectations and provides an increased understanding of the factors that influence adolescent social interactions.

The neuroanatomy of social trust predicts depression vulnerability

Trust attitude is a social personality trait linked with the estimation of others’ trustworthiness. Trusting others, however, can have substantial negative effects on mental health, such as the development of depression. Despite significant progress in understanding the neurobiology of trust, whether the neuroanatomy of trust is linked with depression vulnerability remains unknown. To investigate a link between the neuroanatomy of trust and depression vulnerability, we assessed trust and depressive symptoms and employed neuroimaging to acquire brain structure data of healthy participants. A high depressive symptom score was used as an indicator of depression vulnerability. The neuroanatomical results observed with the healthy sample were validated in a sample of clinically diagnosed depressive patients. We found significantly higher depressive symptoms among low trusters than among high trusters. Neuroanatomically, low trusters and depressive patients showed similar volume reduction in brain regions implicated in social cognition, including the dorsolateral prefrontal cortex (DLPFC), dorsomedial PFC, posterior cingulate, precuneus, and angular gyrus. Furthermore, the reduced volume of the DLPFC and precuneus mediated the relationship between trust and depressive symptoms. These findings contribute to understanding social- and neural-markers of depression vulnerability and may inform the development of social interventions to prevent pathological depression.

Elevated Neurobehavioral Responses to Negative Social Interactions in Women With Bulimia Nervosa

BACKGROUND

Bulimia nervosa (BN) is a complex psychiatric illness that includes binge-purge behaviors and a belief that one's value as a person depends on body shape and weight. Social pressure strongly influences the development and maintenance of BN, but how this manifests neurobiologically within an individual remains unknown. We used a computational psychiatry approach to evaluate neural mechanisms underlying social interactions in BN.

METHODS

Behavioral and functional magnetic resonance imaging data were collected from 24 women with BN and 26 healthy comparison women using an iterated social exchange game. Data were sorted round by round based on whether the mathematically computed social signals indicated an improving (positive reciprocity) or deteriorating (negative reciprocity) relationship for each participant.

RESULTS

Social interactions with negative reciprocity resulted in more negative behavioral responses and stronger neural activations in both cortical and subcortical regions in women with BN than healthy comparison women. No behavioral or neural differences were observed for interactions demonstrating positive reciprocity, suggesting a very specific form of psychopathology in BN: amplification of negative self-relevant social interactions. Cortical activations (e.g., temporoparietal junction and dorsolateral prefrontal cortex) did not covary with mood symptoms, while subcortical activations (e.g., amygdala and dorsal striatum) were associated with acute psychopathology.

CONCLUSIONS

These data provide a first step toward a mechanistic neuropsychological model of aberrant social processing in BN, demonstrating how a computational psychiatric approach can elucidate neural mechanisms for complex psychiatric illnesses. Future treatments for BN may include targeting neural regions that support these negative biases in social perceptions.

Familial Risk Factors in Relation to Recurrent Depression Among Former Adolescent Psychiatric Inpatients

Treating recurrent depression is a challenge for clinical practitioners. We investigated which family environmental factors contribute to differences between recurrent and non-recurrent depression by the young adulthood of the former adolescent inpatients. The initial sample covered 237 adolescent psychiatric inpatients with depression, of which 35.4% had later diagnosed with recurrent depression. Recurrence in depression was associated to distant maternal relationships in both male (p = 0.022) and female patients (p = 0.042). In females, the likelihood for recurrent depression was also related to psychiatric problems of the father (p = 0.013) and siblings (OR = 3.7, p = 0.032), and having a grand multiparous mother (p = 0.005). Our results emphasise the need for effective family-centred approaches in treatment of adolescents with depression.

Resting-State Networks Associated with Behavioral and Self-Reported Measures of Persecutory Ideation in Psychosis

Persecutory ideations are self-referential delusions of being the target of malevolence despite a lack of evidence. Wisner et al. (2021) found that reduced connectivity between the left frontoparietal (lFP) network and parts of the orbitofrontal cortex (OFC) correlated with increased persecutory behaviors among psychotic patients performing in an economic social decision-making task that can measure the anticipation of a partner’s spiteful behavior. If this pattern could be observed in the resting state, it would suggest a functional-structural prior predisposing individuals to persecutory ideation. Forty-four patients in the early course of a psychotic disorder provided data for resting-state functional connectivity magnetic resonance imaging across nine brain networks that included the FP network and a similar OFC region. As predicted, we found a significant and negative correlation between the lFP–OFC at rest and the level of suspicious mistrust on the decision-making task using a within-group correlational design. Additionally, self-reported persecutory ideation correlated significantly with the connectivity between the right frontoparietal (rFP) network and the OFC. We extended the previous finding of reduced connectivity between the lFP network and the OFC in psychosis patients to the resting state, and observed a possible hemispheric difference, such that greater rFP–OFC connectivity predicted elevated self-reported persecutory ideation, suggesting potential differences between the lFP and rFP roles in persecutory social interactions.

Social Trust and Reciprocity Among Adolescent Girls Exposed to Interpersonal Violence

Trauma research has traditionally focused on altered emotion regulation and its role in psychopathology, whereas mechanisms of social behavior remain comparatively unexplored, particularly among adolescents. It has been previously reported that adolescents with histories of interpersonal violence (IV) demonstrate disrupted social learning, and the degree to which they are impaired during social interactions requiring trustful behaviors may be associated with their levels of anxiety. In the present study, 52 adolescent females (n = 26 control; n = 26 IV-exposed) between ages of 11 and 17 completed a multi-round adaptation of the Trust Game in which they interacted with a confederate peer run by a computer program, alternating between the roles of investor and investee. The task was designed to operationalize the social behaviors of trust and trust reciprocity, where the magnitude of the participants' monetary investment in the confederate during the investor role represented trust while the proportion of investment returned to the confederate in the investee role represented trust reciprocity. IV-exposed and control participants did not differ in trust (i.e., as investors); however, IV-exposed participants without anxiety diagnoses demonstrated lower trust than those with anxiety diagnoses. For trust reciprocity (i.e., as investees), there were again no differences between IV-exposed participants and controls; however, IV-exposed participants with anxiety diagnoses had increased trust reciprocity compared with both other groups. Similarly, caregiver-reported anxiety symptoms were associated with trust reciprocity behaviors among the IV-exposed adolescents. Findings suggest that IV exposure and associated anxiety impacts adolescents' trust behaviors, demonstrating potential mechanisms for maladaptive social behavior among trauma-exposed youth.

Multi-Round Trust Game Quantifies Inter-Individual Differences in Social Exchange from Adolescence to Adulthood

Investing in strangers in a socio-economic exchange is risky, as we may be uncertain whether they will reciprocate. Nevertheless, the potential rewards for cooperating can be great. Here, we used a cross sectional sample (n = 784) to study how the challenges of cooperation versus defection are negotiated across an important period of the lifespan: from adolescence to young adulthood (ages 14 to 25). We quantified social behaviour using a multi round investor-trustee task, phenotyping individuals using a validated model whose parameters characterise patterns of real exchange and constitute latent social characteristics. We found highly significant differences in investment behaviour according to age, sex, socio-economic status and IQ. Consistent with the literature, we showed an overall trend towards higher trust from adolescence to young adulthood but, in a novel finding, we characterized key cognitive mechanisms explaining this, especially regarding socio-economic risk aversion. Males showed lower risk-aversion, associated with greater investments. We also found that inequality aversion was higher in females and, in a novel relation, that socio-economic deprivation was associated with more risk averse play.

Understanding identification-based trust in the light of affiliative bonding: Meta-analytic neuroimaging evidence

Trust is vital for establishing social relationships and is a crucial precursor for affiliative bonds. Investigations explored the neuropsychological bases of trust separately (e.g., measured by the trust game) and affiliative bonding (e.g., measured by parental care, pair-bonding, or friendship). However, direct empirical support for the shared neural mechanisms between trust and affiliative bonding is missing. Here, we conducted a coordinate-based meta-analysis on functional magnetic resonance imaging studies on interpersonal trust and affiliative bonding using the activation likelihood estimation method. Our results demonstrated that decisions to trust strangers in repeated interactions (i.e., identification-based trust) engaged the ventral striatum (vSTR, part of the mesolimbic dopaminergic pathway), likely signaling the reward anticipation. Further, both feedbacks in repeated interactions and affiliative bonding engaged the dorsal striatum (dSTR, part of the nigrostriatal dopaminergic pathway), likely encoding learning dynamics. Our findings suggest that identification-based trust can be understood in the light of affiliative bonding, involving the mesocorticolimbic "reward" pathway (vSTR) and nigrostriatal "habit formation" pathway (dSTR) in building and sustaining social relationships.

Exploring the association between social behaviour, trust, and its neural correlates in first episode psychosis patients and in individuals at clinical high risk for psychosis

OBJECTIVES

Psychosis is characterized by paranoid delusions, social withdrawal, and distrust towards others. Trust is essential for successful social interactions. It remains unknown which aspects of social functioning are associated with reduced trust in psychosis. Therefore, we investigated the association between social behaviour, trust, and its neural correlates in a group of individuals with psychotic symptoms (PS-group), consisting of first episode psychosis patients combined with individuals at clinical high risk.

METHODS

We compared 24 PS individuals and 25 healthy controls. Affect and social withdrawal were assessed using the Experience Sampling Method. Trust was measured during functional magnetic resonance imaging (fMRI) scanning, using a trust game with a cooperative and unfair counterpart.

RESULTS

The PS-group showed lower baseline trust compared to controls and reported less positive and more negative general affect. Social withdrawal did not differ between the groups. Social withdrawal and social reactivity in affect (i.e., changes in affect when with others compared to when alone) were not associated with trust. On the neural level, in controls but not in the PS-group, social withdrawal was associated with caudate activation during interactions with an unfair partner. An increase in positive social reactivity, was associated with reduced insula activation in the whole sample.

CONCLUSIONS

Social withdrawal and social reactivity were not associated with reduced initial trust in the PS-group. Like controls, the PS-group showed a positive response in affect when with others, suggesting a decrease in emotional distress. Supporting patients to keep engaging in social interactions, may alleviate their emotional distress.

PRACTITIONER POINTS

Individuals with psychotic symptoms show reduced initial trust towards unknown others. Trust in others is not associated with social withdrawal and reported affect when with others, nor when alone. Like controls, individuals with psychotic symptoms showed reduced negative affect and increased positive affect when with others compared to when alone. We emphasize to support individuals with psychotic symptoms to keep engaging in social interactions, given it may reduce social withdrawal and alleviate their emotional distress.

Are People Altruistic When Making Socially Responsible Investments? Evidence From a tDCS Study

Socially responsible investment (SRI) is an emerging philosophy that integrates social and environmental impacts into investment considerations, and it has gradually developed into an important form of investment. Previous studies have shown that both financial and non-financial motivations account for SRI behaviors, but it is unclear whether the non-financial motive to adopt SRI derives from investors' altruism. This study uses neuroscientific techniques to explore the role of altruism in SRI decision-making. Given that existing evidence has supported the involvement of the right temporoparietal junction (rTPJ) in altruism and altruistic behaviors, we used transcranial direct current stimulation (tDCS) to temporarily modulate activity in the rTPJ and tested its effect on charitable donations and SRI behaviors. We found that anodal stimulation increased the subjects' donations, while cathodal stimulation decreased them, suggesting that tDCS changed the subjects' levels of altruism. More importantly, anodal stimulation enhanced the subjects' willingness to make SRIs, while cathodal stimulation did not have a significant impact. These findings indicate that altruism plays an important role in SRI decision-making. Furthermore, cathodal stimulation changed the subjects' perceived effectiveness of charitable donation but not that of socially responsible fund. This result may help explain the inconsistent effects of cathodal stimulation on charitable donations and SRI behaviors. The main contribution of our study lies in its pioneering application of tDCS to conduct research on SRI behaviors and provision of neuroscientific evidence regarding the role of altruism in SRI decision-making.

Hierarchical Neural Prediction of Interpersonal Trust

Exploring neural markers that predict trust behavior may help us to identify the cognitive process underlying trust decisions and to develop a new approach to promote interpersonal trust. It remains unknown how trust behavior may be predicted early in the decision process. We used electrophysiology to sample the brain activity while participants played the role of trustor in an iterative trust game. The results showed that during the trust generation stage, the trust condition led to higher frontocentral beta band activity related to cognitive inhibition compared to the distrust condition (item level). Moreover, individuals with higher frontocentral beta band activity were more likely to perform trust choices at the single-trial level (individual level). Furthermore, after receiving reciprocity feedback on trial_n-1, compared to the betrayal feedback and the distrust choice, the frontocentral beta band oscillation had a stronger predictive effect regarding trust choices on trial_n. These findings indicate that beta band oscillations during the decision generation stage contribute to subsequent trust choices.

Effect of Maternal Docosahexaenoic Acid (DHA) Supplementation on Offspring Neurodevelopment at 12 Months in India: A Randomized Controlled Trial

Intake of dietary docosahexaenoic acid (DHA 22:6n-3) is very low among Indian pregnant women. Maternal supplementation during pregnancy and lactation may benefit offspring neurodevelopment. We conducted a double-blind, randomized, placebo-controlled trial to test the effectiveness of supplementing pregnant Indian women (singleton gestation) from ≤20 weeks through 6 months postpartum with 400 mg/d algal DHA compared to placebo on neurodevelopment of their offspring at 12 months. Of 3379 women screened, 1131 were found eligible; 957 were randomized. The primary outcome was infant neurodevelopment at 12 months, assessed using the Development Assessment Scale for Indian Infants (DASII). Both groups were well balanced on sociodemographic variables at baseline. More than 72% of women took >90% of their assigned treatment. Twenty-five serious adverse events (SAEs), none related to the intervention, (DHA group = 16; placebo = 9) were noted. Of 902 live births, 878 were followed up to 12 months; the DASII was administered to 863 infants. At 12 months, the mean development quotient (DQ) scores in the DHA and placebo groups were not statistically significant (96.6 ± 12.2 vs. 97.1 ± 13.0, p = 0.60). Supplementing mothers through pregnancy and lactation with 400 mg/d DHA did not impact offspring neurodevelopment at 12 months of age in this setting.

Prediction of trust propensity from intrinsic brain morphology and functional connectome

Trust forms the basis of virtually all interpersonal relationships. Although significant individual differences characterize trust, the driving neuropsychological signatures behind its heterogeneity remain obscure. Here, we applied a prediction framework in two independent samples of healthy participants to examine the relationship between trust propensity and multimodal brain measures. Our multivariate prediction analyses revealed that trust propensity was predicted by gray matter volume and node strength across multiple regions. The gray matter volume of identified regions further enabled the classification of individuals from an independent sample with the propensity to trust or distrust. Our modular and functional decoding analyses showed that the contributing regions were part of three large‐scale networks implicated in calculus‐based trust strategy, cost–benefit calculation, and trustworthiness inference. These findings do not only deepen our neuropsychological understanding of individual differences in trust propensity, but also provide potential biomarkers in predicting trust impairment in neuropsychiatric disorders.

Association between Social Trust and Metabolic Syndrome in a Previously Healthy Population-A Longitudinal Cohort Study in South Korea

Background: Social trust, assessed by the trustworthiness of one another in a community, is known to have beneficial effects on health outcomes. However, the impact of social trust on metabolic syndrome (MetS) is unclear. Methods: The study subjects were extracted from the Korean National Health Insurance Service, and social trust was obtained from the Korean Community Health Survey (KCHS). Previously healthy participants were followed up from 1 January 2010 to 31 December 2011, and again from 1 January 2012 to 31 December 2013 for waist circumference, blood pressure, fasting blood glucose, triglycerides and high-density lipoprotein cholesterol (HDL-C). Multivariate logistic regression was used to calculate the adjusted odds ratios (aORs) with 95% confidence intervals (CIs) for newly developed MetS according to social trust quintiles. Stratified analyses were performed to determine the relationship between lifestyle behaviors and social trust. Results: Compared to the participants within the first quintile of social trust, those in the remaining quintiles had lower risks of developing MetS. The aOR with the 95% CI was 0.88 (0.79–0.98) in the 5th quintile group of social trust. Among the diagnostic criteria for MetS, waist circumference and HDL-C were statistically significant with aORs of 0.91 (0.84–0.99) and 0.88 (0.80–0.95) in the 5th quintile group. The stratified analyses showed protective effects of positive lifestyle behaviors. The aORs with 95% CIs were 0.85 (0.74–0.99) in never smokers, 0.82 (0.70–0.95) in non-drinkers and 0.87 (0.76–1.00) in the physically active in the highest level of social trust. Conclusions: Higher social trust was associated with a lower incidence of MetS. Therefore, building community with psychosocial support may be helpful in improving public health.

Neural Signatures of Gender Differences in Interpersonal Trust

Trust plays a critical role in nearly every aspect of social life. Parental investment theory and social role theory predict that women trust less than men due to a higher sensitivity to risk and betrayal, while men trust more than women to maximize resources and to signal their willingness to lose something. However, the underlying neuropsychological underpinnings for this gender difference are still obscure. In this study, we used functional magnetic resonance imaging (fMRI) to investigate the neural signatures of gender differences in trust by simultaneously scanning 11 male and 11 female same-gender, fixed dyads who played a multi-round binary trust game with varying levels of payoff (low/moderate/high) as an indicator of social risk. Our results showed that men trusted more than women and payoff level moderated the effect of gender on trust. While men trusted the same at all payoff levels, women trusted less with higher payoff levels. This pattern was supported by our neuroimaging finding: men showed a higher activation in the left inferior frontal gyrus (ventrolateral prefrontal cortex) and right precuneus than women, indicating that men exert more effort to inhibit the information of payoff levels and to use self-referencing to infer the strategies of partners with the goal of maximizing profit. Furthermore, men showed equivalent activation in the subgenual anterior cingulate cortex across payoff levels, whereas women showed a decreased activation with increasing payoff level - indicating decreased group bonding with higher risk in women. In conclusion, our results imply that women are more sensitive to social risk while trusting, which has implications for financial interactions, interpersonal relationships, and social involvement.

Effect of Ego Depletion on Interpersonal Trust among Individuals with Substance Use Disorders

Individuals with substance use disorders (SUD) undergo treatment to recover from addiction. However, exerting self-control, which is essential for successful abstinence from drug addiction, can cause ego depletion. This study experimentally investigated the effect of ego depletion on interpersonal trust and examined possible changes in the ego depletion effect across different abstinence periods. This study employed a 2 (ego depletion: high vs. low) × 2 (partners: non-SUD vs. SUD) mixed factorial design. The participants were 273 male individuals with SUD and with periods of drug abstinence ranging from several days to 2 years, who resided in a compulsory drug rehabilitation center. The participants were first asked to complete an ego depletion task, followed by a decision-making task in a trust game, first with a non-SUD stranger, and then with a SUD stranger. Ego depletion was not related to trust in non-SUD strangers. However, ego depleted participants were more likely to trust SUD strangers than non-ego depleted participants. Moreover, this ego depletion effect fluctuated near the end of SUD treatment. This study highlights the importance to ensure follow-up outpatient care and offer social support services for individuals with SUD after compulsory SUD treatment.

The neural mechanisms of social reward in early psychosis

In chronic psychosis, reduced trust is associated with a neural insensitivity to social reward and reduced theory of mind (ToM). Here we investigate whether these mechanisms could underlie emerging social impairments in early psychosis. Twenty-two participants with early psychosis and 25 controls (male, 13–19 years) participated in two interactive trust games against a cooperative and unfair partner. Region of interest neuroimaging analyses included right caudate, medial prefrontal cortex (mPFC) and right temporoparietal junction (rTPJ), involved in reward and ToM processing. Both groups showed similar levels of trust (i.e. investments). However, individuals with psychosis failed to activate the caudate differentially in response to cooperation and unfairness while making decisions to trust. During cooperative returns, patients showed reduced and controls increased caudate activation. Patients demonstrated greater rTPJ activation than controls, possibly pointing towards compensatory mechanisms. Effects were associated with Wechsler Abbreviated Scale of Intelligence vocabulary scores. No group differences emerged in mPFC activation. Early psychosis is associated with an aberrant neural sensitivity to social reward. This could foster reduced social motivation and social isolation. Absent behavioural differences in early, relative to chronic psychosis could indicate that trust is achieved through increased compensatory demand on ToM.

Trust and the city: Linking urban upbringing to neural mechanisms of trust in psychosis

OBJECTIVE

Elevated prevalence of non-affective psychotic disorders is often found in densely populated areas. This functional magnetic resonance imaging study investigates if reduced trust, a component of impaired social functioning in patients with psychotic disorder, is associated with urban upbringing.

METHODS

In total, 39 patients (22 first episode and 17 clinical high risk) and 30 healthy controls, aged 16-29, performed two multi-round trust games, with a cooperative and unfair partner during functional magnetic resonance imaging scanning. Baseline trust was operationalized as the first investment made, and changes of trust as changes in investments made over the 20 trials during the games. Urban exposure during upbringing (0-15 years) was defined as higher urban (≥2500 inhabitants/km²) or lower urban (<2500 inhabitants/km²).

RESULTS

Patients displayed lower baseline trust (first investment) than controls, regardless of urbanicity exposure. During cooperative interactions, lower-urban patients showed increasing investments. In addition, during cooperative interactions, group-by-developmental urbanicity interactions were found in the right and left amygdalae, although for the latter only at trend level. Higher urbanicity was associated with decreased activation of the left amygdala in patients and controls during investments and with increased activation of the right and left amygdalae in patients only, during repayments. During unfair interactions, no associations of urbanicity with behavior or brain activation were found.

CONCLUSION

Urban upbringing was unrelated to baseline trust. Associations with urbanicity were stronger for patients compared to controls, suggesting greater susceptibility to urbanicity effects during the developmental period. Higher-urban patients failed to compensate for the initial distrust specifically during repeated cooperative interactions. This finding highlights potential implications for social functioning. Urban upbringing was linked to differential amygdala activation, suggesting altered mechanisms of feedback learning, but this was not associated with trust game behavior.

Sex differences and brain development during puberty and adolescence

Sex differences in behavior, and whether these behavioral differences are related to sex differences in brain development, has been a longstanding topic of debate. Presumably, sex differences can provide critically important leads for explaining the etiology of various illnesses that show (i) large sex differences in prevalence and (ii) have an origin before or during adolescence. The general aim of this chapter is to provide an overview of scientific studies on sex differences in normative brain and behavioral development across puberty and adolescence, including the (sex) hormone-driven transition phase of puberty. Moreover, we describe the literature on brain and behavioral development in gender dysphoria, a severe and persistent incongruence between the self-identified gender and the assigned sex at birth. From the literature it becomes clear there is evidence for a specific link between pubertal maturation and developmental changes in arousal, motivation, and emotion. However, this link is rather similar between boys and girls. Moreover, although there is substantial evidence for sex differences in mean brain structure, these have not always been linked to sex differences in behavior, cognition, or psychopathology. Furthermore, there is little evidence for sex differences in brain development and thus, studies so far have been unable to explain sex differences in cognition. Suggestions for future research and methodologic considerations are provided.

Developmental Changes and Individual Differences in Trust and Reciprocity in Adolescence

A Trust Game was used to examine trust and reciprocity development in 12-18-year-old-adolescents (N = 496), as findings have been conflicting and transitions in adolescence remain elusive. Furthermore, this study tested the roles of gender, risk, and individual differences in empathy, impulsivity, and antisocial tendencies in trust and reciprocity. Results indicate stability in trust and a decrease in reciprocity across adolescence, but also show that trust and reciprocity choices were influenced by risk, and that empathy mediated the age-related decrease in reciprocity. Males trusted more than females, but there were no gender differences in reciprocity. These findings highlight the importance of considering individual differences and adolescents' sensitivities to varying contexts in explaining trust and reciprocity development in adolescence.

Neural representations of honesty predict future trust behavior

Theoretical accounts propose honesty as a central determinant of trustworthiness impressions and trusting behavior. However, behavioral and neural evidence on the relationships between honesty and trust is missing. Here, combining a novel paradigm that successfully induces trustworthiness impressions with functional MRI and multivariate analyses, we demonstrate that honesty-based trustworthiness is represented in the posterior cingulate cortex, dorsolateral prefrontal cortex and intraparietal sulcus. Crucially, brain signals in these regions predict individual trust in a subsequent social interaction with the same partner. Honesty recruited the ventromedial prefrontal cortex (VMPFC), and stronger functional connectivity between the VMPFC and temporoparietal junction during honesty encoding was associated with higher trust in the subsequent interaction. These results suggest that honesty signals in the VMPFC are integrated into trustworthiness beliefs to inform present and future social behaviors. These findings improve our understanding of the neural representations of an individual’s social character that guide behaviors during interpersonal interactions.

We tend to be more trusting of people who we know to be honest. Here, the authors show using fMRI that honesty-based trustworthiness is represented in the posterior cingulate cortex, dorsolateral prefrontal cortex and intraparietal sulcus, and predicts subsequent trust decisions.

Adolescent Paranoia: Prevalence, Structure, and Causal Mechanisms

BACKGROUND

Adolescence can be a challenging time, characterized by self-consciousness, heightened regard for peer acceptance, and fear of rejection. Interpersonal concerns are amplified by unpredictable social interactions, both online and offline. This developmental and social context is potentially conducive to the emergence of paranoia. However, research on paranoia during adolescence is scarce.

METHOD

Our aim was to examine the prevalence, structure, and probabilistic causal mechanisms of adolescent paranoia. A representative school cohort of 801 adolescents (11-15 y) completed measures of paranoia and a range of affective, cognitive, and social factors. A Bayesian approach with Directed Acyclic Graphs (DAGs) was used to assess the causal interactions with paranoia.

RESULTS

Paranoid thoughts were very common, followed a continuous distribution, and were hierarchically structured. There was an overall paranoia factor, with sub-factors of social fears, physical threat fears, and conspiracy concerns. With all other variables controlled, DAG analysis identified paranoia had dependent relationships with negative affect, peer difficulties, bullying, and cognitive-affective responses to social media. The causal directions could not be fully determined, but it was more likely that negative affect contributed to paranoia and paranoia impacted peer relationships. Problematic social media use did not causally influence paranoia.

CONCLUSIONS

There is a continuum of paranoia in adolescence and occasional suspicions are common at this age. Anxiety and depression are closely connected with paranoia and may causally contribute to its development. Paranoia may negatively impact adolescent peer relationships. The clinical significance of paranoia in adolescents accessing mental health services must now be established.

Girls-Boys: An Investigation of Gender Differences in the Behavioral and Neural Mechanisms of Trust and Reciprocity in Adolescence

BACKGROUND

Trust and reciprocity toward others have often been found to increase from childhood to adulthood. Gender differences in these social behaviors have been reported in adults. While adolescence is a key-period of change in social behavior, gender differences in trust and reciprocity during this developmental stage have rarely been investigated.

METHODS

Here we investigate age-related gender differences in trust and reciprocity (n = 100, 51 female) and associated neural mechanisms (n = 44, 20 female) in adolescents between 13 and 19 years of age. Participants played two multi-round trust games with a pre-programmed cooperative and an unfair partner. Forty-four of 100 participants completed the trust game while undergoing functional brain imaging.

RESULTS

Participants' investments were greater toward a cooperative than unfair game partner (p < 0.01), showing sensitivity to the degree of trustworthiness. There were no gender or age or related differences in baseline trust. In repeated cooperative interactions no gender differences were found, but younger adolescents showed slightly steeper increase of investments than older adolescents. In unfair interactions, younger males reacted with stronger decrease of investments than older males. Region of interest analysis of brain areas associated with in mentalizing, reward learning, conflict processing, and cognitive control revealed gender-by-age interactions on trusting behavior in the temporo-parietal junction (TPJ) and the caudate, showing stronger influence of age in males than in females during cooperation, and the reverse in unfair interactions. Additionally, main effects of gender were found in the TPJ, with higher activation in males, and in the caudate, with females showing greater activation.

CONCLUSION

In first interactions and during repeated cooperative interactions, adolescent males and females showed similar trusting behavior. Younger males showed stronger responses to unfairness by others. Gender-by-age interactions in specific ROIs suggest differential development in mentalizing and reward related cognitive processes. In conjunction with previous research, our findings suggest the presence of subtle gender and age-related changes in trust and cooperation that are only detectable using larger age windows.

Trust and general risk-taking in externalizing adolescent inpatients versus non-externalizing psychiatric controls

Background

Interpersonal trust is an important target for the conceptualization, identification, and treatment of psychiatric disorders marked by interpersonal difficulties. A core feature of adolescent externalising disorders is interpersonal impairment. However, research investigating trust is scarce. A relatively novel approach for studying trust in psychopathology is through examination of social decision making using behavioural economic games.

Objective

To employ a modified trust game in order to determine whether externalising adolescents exhibit perturbed decision making in social and/or nonsocial contexts.

Methods

Externalising inpatient adolescents (n = 141) and non-externalising psychiatric controls (n = 122) completed self-report measures of psychopathology and invested in an iterative trust game played under two conditions: social (trust) and nonsocial (lottery condition), each consisting of five consecutive trials.

Results

Externalising adolescents showed a limited increase in trust investments, compared to a significant increase in lottery investments, across early game trials relative to psychiatric controls. This significant three-way interaction between experimental group, game condition, and trials became most evident at the second trial of games. Between-group differences on trust investments were non-significant. However, externalising adolescents invested significantly less in the trust relative to lottery condition, an effect unobserved in psychiatric controls.

Conclusions

This study tentatively suggests that adolescent externalising disorders may be associated with an insensitivity to normative social exchange which may arise, in part, from a lack of anticipated co-player reciprocity. It is not the level of trust that may distinguish externalising adolescents but perhaps the form of which the trust exchange takes shape. Conclusions are tempered by the fact that the employed trust game did not include feedback in the form of co-player repayments.

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.

Learning to trust: social feedback normalizes trust behavior in first-episode psychosis and clinical high risk

BACKGROUND

Psychosis is characterized by problems in social functioning that exist well before illness onset, and in individuals at clinical high risk (CHR) for psychosis. Trust is an essential element for social interactions that is impaired in psychosis. In the trust game, chronic patients showed reduced baseline trust, impaired response to positive social feedback, and attenuated brain activation in reward and mentalizing areas. We investigated whether first-episode psychosis patients (FEP) and CHR show similar abnormalities in the neural and behavioral mechanisms underlying trust.

METHODS

Twenty-two FEP, 17 CHR, and 43 healthy controls performed two trust games, with a cooperative and an unfair partner in the fMRI scanner. Region of interest analyses were performed on mentalizing and reward processing areas, during the investment and outcome phases of the games.

RESULTS

Compared with healthy controls, FEP and CHR showed reduced baseline trust, but like controls, learned to trust in response to cooperative and unfair feedback. Symptom severity was not associated with baseline trust, however in FEP associated with reduced response to feedback. The only group differences in brain activation were that CHR recruited the temporo-parietal junction (TPJ) more than FEP and controls during investment in the unfair condition. This hyper-activation in CHR was associated with greater symptom severity.

CONCLUSIONS

Reduced baseline trust may be associated with risk for psychotic illness, or generally with poor mental health. Feedback learning is still intact in CHR and FEP, as opposed to chronic patients. CHR however show distinct neural activation patterns of hyper-activation of the TPJ.

Social Mindfulness and Psychosis: Neural Response to Socially Mindful Behavior in First-Episode Psychosis and Patients at Clinical High-Risk

Background: Psychosis is characterized by problems in social functioning and trust, the assumed glue to positive social relations. But what helps building trust? A prime candidate could be social mindfulness: the ability and willingness to see and consider another person’s needs and wishes during social decision making. We investigated whether first-episode psychosis patients (FEP) and patients at clinical high-risk (CHR) show reduced social mindfulness, and examined the underlying neural mechanisms.

Methods: Twenty FEP, 17 CHR and 46 healthy controls, aged 16–31, performed the social mindfulness task (SoMi) during fMRI scanning, spontaneously and after the instruction “to keep the other’s best interest in mind.” As first of two people, participants had to choose one out of four products, of which three were identical and one was unique, differing in a single aspect (e.g., color).

Results: FEP tended to choose the unique item (unmindful choice) more often than controls. After instruction, all groups significantly increased the number of mindful choices compared to the spontaneous condition. FEP showed reduced activation of the caudate and medial prefrontal cortex (mPFC) during mindful, and of the anterior cingulate cortex (ACC), mPFC, and left dorsolateral prefrontal cortex (dlPFC) during unmindful decisions. CHR showed reduced activation of the ACC compared to controls.

Discussion: FEP showed a trend toward more unmindful choices. A similar increase of mindful choices after instruction indicated the ability for social mindfulness when prompted. Results suggested reduced sensitivity to the rewarding aspects of social mindfulness in FEP, and reduced consideration for the other player. FEP (and CHR to a lesser extent) might perceive unmindful choices as less incongruent with the automatic mindful responses than controls. Reduced socially mindful behavior in FEP may hinder the building of trust and cooperative interactions.

Giving others the option of choice: An fMRI study on low-cost cooperation

Successful social relationships require a consideration of a partner's thoughts and intentions. This aspect of social life is captured in the social mindfulness paradigm (SoMi task), in which participants make decisions that either limit or preserve options for their interaction partner's subsequent choice. Here we investigated the neural correlates of spontaneous socially mindful and unmindful behaviours. Functional magnetic resonance data were acquired from 47 healthy adolescents and young adults (age 16-27) as they completed the SoMi task. Being faced with socially relevant choices was associated with activity in the medial prefrontal cortex, anterior cingulate, caudate, and insula, which is consistent with prior neuroeconomical research. Importantly, socially mindful choices were associated with activity in the right parietal cortex and the caudate, whereas unmindful choices were associated with activity in the left prefrontal cortex. These neural findings were consistent with the behavioural preference for mindful choices, suggesting that socially mindful decisions are the basic inclination, whereas socially unmindful responses may require greater effort and control. Together, these results begin to uncover the neural correlates of socially mindful and unmindful choices, and illuminate the psychological processes involved in cooperative social behaviour.