It’s not my fault I am aggressive, they picked on me: How early peer relations affect DNA methylation and neurocognitive development in children

Project Information

socio-bio interplay

Grant agreement ID: 646594

DOI

10.3030/646594

Project closed

EC signature date 29 June 2015

Start date 1 July 2015

End date 31 December 2020

Funded under

• EXCELLENT SCIENCE - European Research Council (ERC)

Total cost

€ 1 962 679,00

EU contribution

€ 1 962 679,00

Coordinated by

STICHTING VU
Netherlands

Periodic Reporting for period 4 - socio-bio interplay (It’s not my fault I am aggressive, they picked on me: How early peer relations affect DNA methylation and neurocognitive development in children)

Reporting period: 2019-09-01 to 2020-12-31

Summary of the context and overall objectives of the project

Each year, approximately 190,000 children in the Netherlands enter kindergarten or elementary school. These children enter a new social environment, the classroom, with new social interactions with teachers and age-matched peers. Most of these children will have positive social experiences, but 10-15% of children become rejected, victim of bullying, have few friends and have poor relations with teachers. Such experiences have been linked to aggression development in children, but we poorly understand how.
This project was set out to study how adverse social experiences in kindergarten and elementary school become embodied in the neurobiology of children, to explain aggression development. Specifically, the project aimed to understand how social experiences inflict aggression by (1) silencing genes underlying stress system responses, leading to impeded stress regulation, and by (2) affecting neurocognitive functions, thereby hindering children's self-regulation abilities.
The project goals with respect to data collection were all obtained.
The overall results of the project showed that (1) children's self-regulatory abilities and social decision making become intertwined with symptoms of psychopathology development already during the elementary school period. (2) that epigenetic processes may link childhood adverse social experiences with the development of antisocial behaviour. (3) That elementary school poor social experiences with peers may link to affected stress-regulation, and (4) that stress from the broader environment may amplify the impact of elementary school social stressors in the prediction of psychopathology) . And (5) that a history of poor social experiences during the early years of elementary school may shape children's neural responses to a new (in vivo) adverse social experience.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

Main objective 1:
Study the impact of elementary school social experiences on DNA methylation and cognitive development above and beyond possible genetic effects in monozygotic twins concordant/discordant on bully-victimization.
Data from 196 monozygotic twin pairs are currently being collected. Data are collected at two time-points, when the twins are on average seven years old, and one year later, when the twins are on average 8 years old. Twins, classmates, and teachers are informants.

Main objective 2:
Study the cross-time influence of multiple adverse and protective social experiences with peers and teachers to test for possible cascading, accentuation and buffering between different social experiences, and test for sex-differences in these influences in a longitudinal observational study of children followed across elementary school.
Data among 1000+ children attending mainstream elementary schools have been collected. Children have been assessed annually across the elementary school years (age 5 - 12 years). Teacher, peer, and self-report data on children's social relations and social experiences with teachers and classroom peers, and on children's psychopathology have been collected. Test scores of children's social decision making, working-memory, risk-taking, and behavioral inhibition were obtained annually. Three waves of DNA have also been collected, and DNA epigenetic analyses (EPIC array) are currently conducted.

Main objective 3:
Study hypothesized stress- and self-regulatory variables that mediate the effects of altered DNA methylation and altered neurocognitive functions on aggressive responses. Children discordant on their social experiences in school will be tested in two lab-experimental studies.
In study 1, 70 children (50% rejected) were tested in an fMRI study. In the fMRI experiement, children completed a dictator game, followed by a social exclusion task (Cyberball), followed by a second dictator game.
55 children (50% rejected) were invited to participate in the stress-lab study. Children's heart rate and cortisol concentrations were administered during the lab-assessment. Children first completed the BART-task, followed by a social exclusion experience. Children then completed the social decisions task (Hungry Donkey task).

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

Studying the impact of school social experiences on the neurobiology of children is crucial for our understanding of childhood aggression development. Approximately 15-30% of all children show aggression prior to elementary school, but only 5-10% become chronically aggressive. What is intriguing is that children who become chronically aggression do not differ from those who desist in aggression on their genetic or cognitive risk prior to entering elementary school. A crucial objective regarding aggression development is therefore to understand how despite similar levels of neurobiological risk prior to elementary school only some children develop into chronic aggression, while others show decreases in their aggression to low or absent levels by the end of elementary school. This project is set out to study the embodiment of adverse social experiences by shaping neurobiological, i.e. psychophysiological and neurocognitive processes underlying aggression development.
The overall results of the project showed that (1) children's self-regulatory abilities and social decision making become intertwined with symptoms of psychopathology development already during the elementary school period. (2) that epigenetic processes may link childhood adverse social experiences with the development of antisocial behaviour. (3) That elementary school poor social experiences with peers may link to affected stress-regulation, and (4) that stress from the broader environment may amplify the impact of elementary school social stressors in the prediction of psychopathology) . And (5) that a history of poor social experiences during the early years of elementary school may shape children's neural responses to a new (in vivo) adverse social experience.