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.

Longitudinal neural and behavioral trajectories of charity contributions across adolescence.

This study examined the development of prosocial charity donations and neural activity in the ventral striatum when gaining rewards for self and for charity. Participants 10-22 years (95% European heritage) participated in three annual behavioral-fMRI waves (T1: n = 160, T2: n = 167, T3: n = 175). Behaviorally, donations to charity as measured with an economic Dictator Game increased with age. Perspective taking also increased with age. In contrast, self-gain and charity-gain enjoyment decreased with age. Ventral striatum activity was higher for rewards for self than for charity, but this difference decreased during adolescence. Latent growth curve models revealed that higher donations were associated with a smaller difference between ventral striatum activation for self and charity. These findings show longitudinal brain-donations associations in adolescence.

Variability and change in adolescents' prosocial behavior across multiple time scales.

We examined variability and change in adolescents' prosocial behaviors directed to peers and friends across four time scales: two-years, one-year, two-monthly, and daily. Data from three longitudinal datasets with a total of 569 adolescents (55.7% girl, Mage  = 15.23, SD = 3.90) were included. The overall time-related stability of prosocial behavior across time scales was moderate to excellent. Variability did not differ between early (age 10-15) and late (age 16-21) adolescence, but late adolescence was associated with higher mean levels of prosociality. Finally, results indicated that prosocial behaviors measured over longer periods (i.e., two-years and one-year) were positively associated with cognitive processes (perspective taking), whereas prosocial behaviors measured over shorter periods (i.e., two-monthly) were positively associated with affective processes (empathy).

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.

Longitudinal Change in Adolescent Depression and Anxiety Symptoms from before to during the COVID-19 Pandemic.

This study aimed to examine changes in depression and anxiety symptoms from before to during the first 6 months of the COVID-19 pandemic in a sample of 1,339 adolescents (9-18 years old, 59% female) from three countries. We also examined if age, race/ethnicity, disease burden, or strictness of government restrictions moderated change in symptoms. Data from 12 longitudinal studies (10 U.S., 1 Netherlands, 1 Peru) were combined. Linear mixed effect models showed that depression, but not anxiety, symptoms increased significantly (median increase = 28%). The most negative mental health impacts were reported by multiracial adolescents and those under 'lockdown' restrictions. Policy makers need to consider these impacts by investing in ways to support adolescents' mental health during the pandemic.

Moral Beauty During the COVID-19 Pandemic: Prosocial Behavior Among Adolescents and the Inspiring Role of the Media.

In this study, we examined whether adolescents helped others during the COVID-19 pandemic and how stories in the media inspired them in doing so. Using an online daily diary design, 481 younger adolescents (M = 15.29, SD = 1.76) and 404 older adolescents (M = 21.48, SD = 1.91) were followed for 2 weeks. Findings from linear mixed effects models demonstrated that feelings of being moved by stories in the media were related to giving emotional support to family and friends, and to helping others, including strangers. Exposure to COVID-19 news and information was found to spark efforts to support and help as well and keeping physical distance in line with the advised protective behaviors against COVID-19. Moreover, helping others was related to increased happiness. Overall, the findings of this study highlight the potential role of the media in connecting people in times of crisis.

Familiarity and Audience Effects on Giving: A Functional Magnetic Resonance Imaging Study.

Giving is often characterized by the conflicting decision to give up something of value to benefit others. Recent evidence indicated that giving is highly context-dependent. To unravel the neural correlates of social context, in this study, young adults (n = 32) performed a novel giving fMRI paradigm, in which they divided coins between self and known (friends) or unknown (unfamiliar) others. A second manipulation included presence of others; giving decisions were made with an audience or anonymously. Results showed that participants gave more coins to a friend than to an unfamiliar other and generally gave more in the presence of an audience. On a neural level, medial prefrontal cortex and the right insula were most active for relatively generous decisions. These findings possibly reflect that aversion of norm deviation or fairness concerns drive differences in the frequency of giving. Next, activation in separate subregions of the TPJ-IPL (i.e., a region that comprises the TPJ and inferior parietal lobule) was found for target and audience contexts. Overall, our findings suggest that donation size and social contextual information are processed in separable brain regions and that TPJ-IPL plays an important role in balancing self- and other-oriented motives related to the social context.

Giving to Friends, Classmates, and Strangers in Adolescence.

This study examined how perspective taking and sensitivity to social rewards predict giving to friends, classmates, and strangers in adolescence. Five hundred and twenty adolescents aged 12-17 years completed questionnaires on perspective taking and social rewards and played three Dictator Games in which they divided coins between themselves and a friend, classmate, and stranger. We found that, irrespective of age, adolescents donated most to a friend, less to their classmate, and least to a stranger, and females donated more than males. Individual differences in perspective taking and social reward sensitivity moderated how much adolescents donated, especially to strangers. These findings suggest that perspective taking and sensitivity to social rewards influence giving behavior in adolescence, especially to unknown others.

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.

Can adolescents be game changers for 21st-century societal challenges?

Adolescents growing up in the 21st century face novel challenges that affect today's adolescents differently compared with previous generations. Adolescents' prosocial values and social engagement can contribute in unique ways to combatting societal challenges. Participatory research provides tools to transform adolescents' prosocial motivations into drivers for societal change.

From developmental neuroscience to policy: A novel framework based on participatory research.

Insights from developmental neuroscience are not always translated to actionable policy decisions. In this review, we explore the potential of bridging the gap between developmental neuroscience and policy through youth participatory research approaches. As the current generation of adolescents lives in an increasingly complex and rapidly changing society, their lived experiences are crucial for both research and policy. Moreover, their active involvement holds significant promise, given their heightened creativity and need to contribute. We therefore advocate for a transdisciplinary framework that fosters collaboration between developmental scientists, adolescents, and policy makers in addressing complex societal challenges. We highlight the added value of adolescents' lived experiences in relation to two pressing societal issues affecting adolescents' mental health: performance pressure and social inequality. By integrating firsthand lived experiences with insights from developmental neuroscience, we provide a foundation for progress in informed policy decisions.

Mood variability during adolescent development and its relation to sleep and brain development.

Mood swings, or mood variability, are associated with negative mental health outcomes. Since adolescence is a time when mood disorder onset peaks, mood variability during this time is of significant interest. Understanding biological factors that might be associated with mood variability, such as sleep and structural brain development, could elucidate the mechanisms underlying mood and anxiety disorders. Data from the longitudinal Leiden self-concept study (N = 191) over 5 yearly timepoints was used to study the association between sleep, brain structure, and mood variability in healthy adolescents aged 11-21 at baseline in this pre-registered study. Sleep was measured both objectively, using actigraphy, as well as subjectively, using a daily diary self-report. Negative mood variability was defined as day-to-day negative mood swings over a period of 5 days after an MRI scan. It was found that negative mood variability peaked in mid-adolescence in females while it linearly increased in males, and average negative mood showed a similar pattern. Sleep duration (subjective and objective) generally decreased throughout adolescence, with a larger decrease in males. Mood variability was not associated with sleep, but average negative mood was associated with lower self-reported energy. In addition, higher thickness in the dorsolateral prefrontal cortex (dlPFC) compared to same-age peers, suggesting a delayed thinning process, was associated with higher negative mood variability in early and mid-adolescence. Together, this study provides an insight into the development of mood variability and its association with brain structure.

Temporal discounting for self and friends in adolescence: A fMRI study.

Adolescence is characterized by impulsivity but also by increased importance of friendships. This study took the novel perspective of testing temporal discounting in a fMRI task where choices could affect outcomes for 96 adolescents (aged 10-20-years) themselves and their best friend. Decisions either benefitted themselves (i.e., the Self Immediate - Self Delay' condition) or their friend (i.e., 'Friend Immediate - Friend Delay' condition); or juxtaposed rewards for themselves and their friends (i.e., the 'Self Immediate - Friend Delay' or 'Friend Immediate - Self Delay' conditions). We observed that younger adolescents were more impulsive; and all participants were more impulsive when this was associated with an immediate benefit for friends. Individual differences analyses revealed increased activity in the subgenual anterior cingulate cortex extending in the ventral striatum for immediate relative to delayed reward choices for self. Temporal choices were associated with activity in the prefrontal cortex, parietal cortex, insula, and ventral striatum, but only activity in the right inferior parietal lobe was associated with age. Finally, temporal delay choices for friends relative to self were associated with increased activity in the temporo-parietal junction and precuneus. Overall, this study shows a unique role of the social context in adolescents' temporal decision making.

Pathways for engaging in prosocial behavior in adolescence.

Adolescent development is often regarded as a period of social sensitivities, given that brain development continues into the early 20s in interplay with social experiences. In this review, we present adolescence as a unique window for prosocial development; that is, behavior that benefits others. We present evidence for multiple pathways of neural sensitivity that contribute to key developmental processes related to prosocial behaviors, including valuing, perspective taking, and goal-flexibility. Yet, these processes are dependent on several contextual factors including recipients, audience effects, and strategic motivations. Next, we present intervention findings suggesting that prosocial experiences within these various contexts are crucial for adolescents developing into engaged and contributing members of society. These findings suggest a new interpretation of the elevated socio-affective sensitivity and emerging socio-cognitive development in adolescence, focusing on opportunities rather than risks.

Growing in generosity? The effects of giving magnitude, target, and audience on the neural signature of giving in adolescence.

Giving is essential for forming and maintaining social relationships, which is an important developmental task for adolescents. This pre-registered fMRI study investigated behavioral and neural correlates of adolescents' (N = 128, ages 9 - 19 years) small versus large size giving in different social contexts related to target (i.e., giving to a friend or unfamiliar peer) and peer presence (i.e., anonymous versus audience giving). Participants gave more in the small size than large size condition, more to friends than to unfamiliar peers, and more in the audience compared to anonymous condition. Giving very small or large amounts was associated with increased activity in the medial prefrontal cortex (mPFC) and anterior insula (AI), and older adolescents showed increased lateral and anterior PFC activation for small size giving. We observed activity in the intraparietal cortex (IPL), dorsolateral prefrontal cortex, and AI for giving to friends, but no age-related differences in this activity. Behaviorally, in contrast, we observed that older adolescents differentiated more in giving between friends and unfamiliar peers. Finally, we observed interactions between peer presence and target in the AI, and between giving magnitude and target in the precuneus. Together, findings reveal higher context-dependency of giving and more lateral PFC activity for small versus large giving in older adolescents.

Daily prosocial actions during the COVID-19 pandemic contribute to giving behavior in adolescence.

Prosocial actions are a building block for developing mature and caring social relations. However, the global pandemic may hamper adolescents' prosocial actions. In this preregistered study, we examined the extent to which adolescents provided daily emotional support during the COVID-19 pandemic. In total, 10-25-year-old high school and university students participated at three timepoints (N = 888 at the first timepoint (May 2020); 494 at the second timepoint (Nov 2020) and 373 at the third timepoint (May 2021)). At the first and second timepoint, participants completed 2 weeks of daily diaries on providing emotional support. At all timepoints, participants performed Dictator Games to measure giving to peers, friends and COVID-19 targets (medical doctors, COVID-19 patients, individuals with a poor immune system). Across the three timepoints, adolescents gave more to COVID-19 targets than peers and friends, but giving to COVID-19 target was highest in the beginning of the pandemic (first timepoint relative to second and third timepoint). Results from the first timepoint showed that emotional support directed to friends peaked in mid-adolescence, whereas emotional support towards family members showed a gradual increase from childhood to young adulthood. Furthermore, daily emotional support increased between the first and second timepoint. Daily emotional support to friends predicted giving behavior to all targets, whereas emotional support to family was specifically associated with giving to COVID-19 targets. These findings elucidate the relation between daily actions and prosocial giving to societally-relevant targets in times of crisis, underlying the importance of prosocial experiences during adolescence.

Happy for Us not Them: Differences in neural activation in a vicarious reward task between family and strangers during adolescent development.

During adolescence social-interactions with other people become more relevant. One key aspect of these interactions is cooperative behavior. Cooperation relies on a set of cognitive and affective mechanisms. In this study, we focused on the mental ability to feel happy for another person's positive experience, called vicarious joy. We investigated the neural mechanisms of this ability using a false-choice vicarious reward fMRI task. Participants played a game where they could win monetary rewards for themselves, their mother, their father, and a stranger. A region-of-interest (ROI) analysis of the Nucleus Accumbens revealed robust activation in this region for personal reward as well as vicarious rewards for both parents. Vicarious reward for a stranger was not associated with activation within the Nucleus Accumbens. ROI activation was associated with self-reported vicarious joy for mother and father. A Prisoner's Dilemma game outside the scanner showed an increase in cooperative behavior until age 14 for parents and strangers, followed by a decline for the stranger but not for the parents. Together, these findings demonstrate that adolescence is an important time for developing ingroup-outgroup relations.

Mood and emotional reactivity of adolescents during the COVID-19 pandemic: short-term and long-term effects and the impact of social and socioeconomic stressors.

Adolescence is a formative period for socio-emotional development which is threatened by the COVID-19 pandemic. The current longitudinal study examined two aims: (1) the short- and long-term effects of the pandemic on young people's mood (i.e. vigor, tension, and depression levels) and emotional reactivity (i.e. fluctuations in daily mood), and (2) the impact of stressors on mood, emotional reactivity, self-oriented (i.e. maladaptive behavior towards COVID-19 rules) and other-benefitting behaviors (i.e. behavior aimed at helping and comforting others). We conducted an online two-week daily diary study among 462 Dutch adolescents (Mage = 15.27 years, 64% females) and 371 young adults (Mage = 21.49 years, 81% females) in May 2020, with a follow-up in November 2020 (N = 238 and 231, respectively adolescents and young adults). In May 2020, young adults and older relative to younger adolescents showed higher levels and more fluctuations in tension and depression and lower levels of vigor. Vigor levels decreased and tension and depression levels increased between May 2020 and November 2020, especially for younger adolescents. There were positive associations between instability of negative emotions (i.e. tension and depression fluctuations) and the exposure to stressors (i.e. family stress and inequality of online homeschooling) in the adolescent sample. Together, this study demonstrates vulnerability regarding young people's mood and emotional reactivity during the COVID-19 pandemic, especially for adolescents who experience more stressors.

A daily diary study on adolescents' mood, empathy, and prosocial behavior during the COVID-19 pandemic.

Adolescence is a formative phase for social development. The COVID-19 pandemic and associated regulations have led to many changes in adolescents' lives, including limited opportunities for social interactions. The current exploratory study investigated the effect of the first weeks of COVID-19 pandemic lockdown on Dutch adolescents' (N = 53 with attrition, N = 36 without attrition) mood, empathy, and prosocial behavior. Longitudinal analyses comparing pre-pandemic measures to a three-week peri-pandemic daily diary study showed (i) decreases in empathic concern, opportunities for prosocial actions, and tension, (ii) stable levels of social value orientation, altruism, and dire prosociality, and (iii) increased levels of perspective-taking and vigor during the first weeks of lockdown. Second, this study investigated peri-pandemic effects of familiarity, need, and deservedness on giving behavior. To this end, we utilized novel hypothetical Dictator Games with ecologically valid targets associated with the COVID-19 pandemic. Adolescents showed higher levels of giving to a friend (a familiar other, about 51% of the total share), a doctor in a hospital (deserving target, 78%), and individuals with COVID-19 or a poor immune system (targets in need, 69 and 63%, respectively) compared to an unfamiliar peer (39%) This suggests that during the pandemic need and deservedness had a greater influence on adolescent giving than familiarity. Overall, this study demonstrates detrimental effects of the first weeks of lockdown on adolescents' empathic concern and opportunities for prosocial actions, which are important predictors of healthy socio-emotional development. However, adolescents also showed marked resilience and a willingness to benefit others as a result of the lockdown, as evidenced by improved perspective-taking and mood, and high sensitivity to need and deservedness in giving to others.

Increasing interpersonal trust through divergent thinking.

Interpersonal trust is an essential ingredient of many social relationships but how stable is it actually, and how is it controlled? There is evidence that the degree of trust into others might be rather volatile and can be affected by manipulations like drawing attention to personal interdependence or independence. Here we investigated whether the degree of interpersonal trust can be biased by inducing either a more integrative or a more focused/exclusive cognitive control mode by means of a creativity task requiring divergent or convergent thinking, respectively. Participants then performed the trust game, which provides an index of interpersonal trust by assessing the money units one participant (the trustor) transfers to another (the trustee). As expected, trustors transferred significantly more money to trustees after engaging in divergent thinking as compared to convergent thinking. This observation provides support for the idea that interpersonal trust is controlled by domain-general (i.e., not socially dedicated) cognitive states.