Chi Ying Jasmine Lee

Developmental Course of Peer Problems and Co-occurring Behavioural Problems During Childhood and Adolescence (Age 5–17)


Purpose: Peer relationships are crucial to psychosocial development, and peer difficulties in childhood predict behavioural difficulties later in life. Yet, there is a lack of literature on the developmental trajectory of peer problems. I aim to identify common peer problem profiles and map their longitudinal transitions across childhood and adolescence.

Method: Strengths and Difficulties Questionnaire data from the population-representative Millennial Cohort Study was analysed with factor analysis, followed by a data-driven clustering approach to extract subgroups of peer and co-occurring problems from ages 5 to 17. I then mapped the transitions between profiles and identified risk factors predicting significant transitions.

Results: Peer problems often co-occurred with other behavioural problems. As children developed from 5 to 7, the peer problem clusters gradually became broader, encompassing emotional difficulties and hyperactivity. From 7 to 11 the profile became refined, returning to mainly peer problems; then from 11 to 14 the peer problem phenotype expanded again to include emotion and hyperactivity issues. Longitudinal and concurrent risk factors at ages 5, 7, and 11 were identified to predict these negative transitions.

Conclusion: Peer problems show a non-linear trajectory of change when tracked longitudinally through childhood and adolescence. Whilst they generally increase with time, they are associated with different co-occurring difficulties and form complex profiles throughout development. These transitions are, to some extent, predictable on the basis of risk factors such as child longstanding illness, time spent on sports and exercise, and parental mental health.

Keywords: peer problems, behavioural development, childhood, adolescence, longitudinal cohort


Received: July 18, 2022
Revision recieved: August 22, 2022
Accepted: August 30, 2022
Published: October 4, 2022







Appendix A | CONSORT Diagrams

Appendix B | Factor analysis scree plots for all sweeps

Appendix C | ANOVA and Post-Hoc Tests

Appendix D | UMAP Parameters

Appendix E | Table of Risk Factors With Variable Codes

Appendix F | Table Showing Extracted Factors and Associated SDQ Items

Appendix G | Factor Analysis Correlation Plots and Loading Matrices for All Sweeps Except MCS7

Appendix H | Visualisation of MCS3 to MCS6

Note. Projection with KMeans clustering in UMAP space, silhouette plot, C-H plot, radar plots, table of cluster characteristics.

Appendix I | Tables Showing Transitions From MCS3 Through MCS7



Ethnographic engagements with the risks and troubles of growing up
Inika Murkumbi
Selwyn College, University of Cambridge

Both psychology and social anthropology are fascinated by a shared field of questions on how infants are fashioned into complete persons. Both are also fascinated with the risks and troubles this transformation may entail. The robustness and wide range of the Millennium Cohort Study and the intimacy and flexibility of social anthropology’s ethnographic method can be reimagined as excitingly complementary (rather than in conflict). Ethnography might challenge assumptions that certain developmental stages are inevitably laden with certain profiles of problems, widen our mental landscape of culturally salient peer/behavioural problems, and provide a holistic view of how peer/behavioural problems that are troublesome in their immediate context might be understood as valuable and generative in the larger context of a community’s value-system.


A brief comment on the molecular genetics of hyperactivity and its associated disorders
Sai Hou Chong
Homerton College, University of Cambridge

Lee describes hyperactivity as a substantial co-occurrence with peer relationships. To provide further depth, this commentary aims to provide brief contextual information on the available evidence on the genetic basis of hyperactivity or attention-deficit hyperactivity disorder at large. Greater emphasis is placed onto genome-wide and transcriptome-wide association studies (GWAS and TWAS respectively), which aim to study the many common genetic variants that have small but additive effect on ADHD severity, with brief descriptions of rarer mutations with more significant associations with ADHD.