More than the sum of its parts: Cumulative risk effects on school functioning in middle childhood.

BACKGROUND: Risk factors for poor school functioning rarely occur in isolation, but instead are likely to cluster together. As they accumulate, cumulative risk theory (CRT) predicts that the likelihood of negative outcomes increases, often disproportionately.

AIMS: We build upon and extend previous research by (i) examining two critical aspects of school functioning (reading attainment and behavioural difficulties); (ii) utilizing a large number of candidate risk factors across multiple ecological domains; (iii) testing the two core assumptions of CRT; and (iv) formally examining the functional form of the risk-outcome relationships.

SAMPLE: Participants were N = 3084 children aged 6-7 attending 77 mainstream primary schools in England.

METHODS: Sixteen candidate risk factors (e.g., familial poverty) were modelled using data from the National Pupil Database. Reading attainment and behavioural difficulties data were generated via teachers' reading assessment scores and the Teacher Observation of Children's Adaptation Checklist (disruptive behaviour subscale), respectively. A cumulative risk score was generated for each pupil. Multilevel modelling was utilized for analysis.

RESULTS: Six risk factors were identified for behaviour and seven for reading attainment. A cumulative risk effect was found for both outcomes, and the two core assumptions of CRT were supported. Quadratic relationships were found for both aspects of school functioning, indicative of a threshold effect.

CONCLUSIONS: As the number of risk factors increases, difficulties in school functioning increase disproportionately. Consistent with CRT, our results suggest that the number of risks is more important than their nature. This has implications for future risk research and the implementation of school-based interventions.