Transitioning from childhood into adolescence: A comprehensive longitudinal behavioral and neuroimaging study on prosocial behavior and social inclusion

Development of Self-Concept in Childhood and Adolescence: How Neuroscience Can Inform Theory and Vice Versa

How do we develop a stable and coherent self-concept in contemporary times? Susan Harter's original work, The Construction of Self (1999; 2012), argues that cognitive and social processes are building blocks for developing a coherent sense of self, resulting in self-concept clarity across various domains in life (e.g., [pro-]social, academic, and physical). Here, we show how this framework guides and can benefit from recent findings on (1) the prolonged and nonlinear structural brain development during childhood and adolescence, (2) insights from developmental neuroimaging studies using self-concept appraisal paradigms, (3) genetic and environmental influences on behavioral and neural correlates of self-concept development, and (4) youth's perspectives on self-concept development in the context of 21st century global challenges. We examine how neuroscience can inform theory by testing several compelling questions related to stability versus change of neural, behavioral, and self-report measures and we reflect on the meaning of variability and change/growth.

Wanting to matter and learning to care: A neurodevelopmental window of opportunity for (Pro) social learning?

Wanting to matter-to feel socially recognized, appreciated, and capable of actions that benefit others-represents a fundamental motivation in human development. The motivational salience of mattering appears to increase in adolescence. Evidence suggests this is related to pubertal increases in the incentive salience for gaining social value and personal agency. This can provide a useful heuristic for understanding motivational proclivities (i.e. wanting to matter) that influence action-outcome learning as young adolescents are exploring and learning how to navigate increasingly complex social and relational environments. Adolescence also brings new capacities, motives, and opportunities for learning to care about and contribute to the benefit of others. Together, these create a window of opportunity: a sensitive period for learning to gain salient feelings of mattering through caring prosocial actions and valued societal contributions. Successfully discovering ways of mattering by doing things that matter to others may contribute to formative socio-emotional learning about self/other. Advances in understanding these social and relational learning processes and their neurodevelopmental underpinnings can inform strategies to improve developmental trajectories of social competence and wellbeing among adolescents growing up in a rapidly changing and increasingly techno-centric world.

Third-party punishment-like behavior in a rat model

Third-party punishment (TPP) is an altruistic behavior or sense willing to punish transgressors as a third party not directly involved in the transgression. TPP is observed worldwide, regardless of tradition and culture, and is essential for morality in human society. Moreover, even preverbal infants display TPP-like judgement, suggesting that TPP is evolutionarily conserved and innate. Thus, it is possible that non-human animals display TPP-like behavior, although TPP has been said to be human-specific. We investigated whether or not male mature Wistar rats displayed TPP-like behaviors when they witnessed deadly aggression by an unknown aggressive mouse toward another unknown victim mouse. Normally reared rats did not display TPP-like behaviors, but rats reared with extensive affectionate handling by human caretakers as beloved pets contacted the unknown aggressive mice in a gentle manner leading to reduced aggression toward the unknown victim mice, even when the aggressive mice fought back. Furthermore, the handled rats touched unknown rat pups that were drowning in water and anesthesia-induced comatose rats more frequently than control rats. These findings suggest a possibility that TPP is not in fact human-specific and innate but rather an acquired behavior that flourishes in affectionate circumstances.

Genetic and environmental influences on structural brain development from childhood to adolescence: A longitudinal twin study on cortical thickness, surface area, and subcortical volume

The human brain undergoes structural development from childhood to adolescence, with specific regions in the sensorimotor, social, and affective networks continuing to grow into adulthood. While genetic and environmental factors contribute to individual differences in these brain trajectories, the extent remains understudied. Our longitudinal study, utilizing up to three biennial MRI scans (n=485), aimed to assess the genetic and environmental effects on brain structure (age 7) and development (ages 7-14) in these regions. Heritability estimates varied across brain regions, with all regions showing genetic influence (ranging from 18 % to 59 %) with additional shared environmental factors affecting the primary motor cortex (30 %), somatosensory cortex (35 %), DLPFC (5 %), TPJ (17 %), STS (17 %), precuneus (10 %), hippocampus (22 %), amygdala (5 %), and nucleus accumbens (10 %). Surface area was more genetically driven (38 %) than cortical thickness (14 %). Longitudinal brain changes were primarily driven by genetics (ranging from 1 % to 29 %), though shared environment factors (additionally) influenced the somatosensory cortex (11 %), DLPFC (7 %), cerebellum (28 %), TPJ (16 %), STS (20 %), and hippocampus (17 %). These findings highlight the importance of further investigating brain-behavior associations and the influence of enriched and deprived environments from childhood to adolescence. Ultimately, our study can provide insights for interventions aimed at supporting children's development.

Behavioral and neural responses to social rejection: Individual differences in developmental trajectories across childhood and adolescence

Dealing with social rejection is challenging, especially during childhood when behavioral and neural responses to social rejection are still developing. In the current longitudinal study, we used a Bayesian multilevel growth curve model to describe individual differences in the development of behavioral and neural responses to social rejection in a large sample (n > 500). We found a peak in aggression following negative feedback (compared to neutral feedback) during late childhood, as well as individual differences during this developmental phase, possibly suggesting a sensitive window for dealing with social rejection across late childhood. Moreover, we found evidence for individual differences in the linear development of neural responses to social rejection in our three brain regions of interest: The anterior insula, the medial prefrontal cortex, and the dorsolateral prefrontal cortex. In addition to providing insights in the individual trajectories of dealing with social rejection during childhood, this study also makes a meaningful methodological contribution: Our statistical analysis strategy (and can be found in this study's online supplementary materials at https://jeroendmulder.github.io/social-emotion-regulation/) can be used as an example on how to take into account the many complexities of developmental neuroimaging datasets, while still enabling researchers to answer interesting questions about individual-level relationships.