No effect of classroom sharing on educational achievement in twins: a prospective, longitudinal cohort study
- T J C Polderman1,2,
- M Bartels1,
- F C Verhulst2,
- A C Huizink2,3,
- C E M van Beijsterveldt1,
- D I Boomsma1
- 1Department of Biological Psychology, VU University Amsterdam, Amsterdam, The Netherlands
- 2Erasmus University Medical Center - Sophia Children’s Hospital, Department of Child and Adolescent Psychiatry, Rotterdam, The Netherlands
- 3Department of Education, University of Amsterdam, The Netherlands
- Correspondence to Dr T J C Polderman, Department of Biological Psychology, VU University Amsterdam, Van der Boechorststraat 1, 1081 BT, Amsterdam, The Netherlands;
- Accepted 20 July 2009
Background: A returning dilemma for families with multiple births is whether twins should share the same, or a parallel classroom, or in other words, whether they should be separated at school or not. This study investigated the effects of sharing a classroom during primary school on cognitive achievement in twins.
Method: Subjects were 839 monozygotic and 1164 dizygotic twin pairs who were registered at birth at The Netherlands Twin Register. A prospective, longitudinal study design was used with educational achievement at age 12 years, measured with a standardised test (CITO test), as outcome measure.
Results: Most twin pairs (72%) shared a classroom during their schooling, 19% were in separate, but parallel, classes, and 9% “partly” shared a classroom. Twins who were in parallel classrooms had higher CITO scores (mean 539.51; SD 8.12), compared to twins who shared a classroom (537.99; SD 8.52). When controlling for socioeconomic status, and externalising problems before starting primary school (age 3), there was no significant difference in educational achievement between separated and non-separated twin pairs (p = 0.138). In addition, there was no interaction with sex or zygosity of the twins (p = 0.798).
Conclusion: There is no difference in educational achievement between twins who share a classroom and twins who do not share a classroom during their primary school time. The choice of separation should be made by teachers, parents and their twin children, based on individual characteristics of a twin pair.
Funding This work was supported by NWO 904-57-94, NWO/SPI 56-464-14192; NWO 480-04-004; NIMH, RO1 MH58799-03. TJCP is funded by Sophia Foundation for Scientific Research (SSWO, no. 562).
Competing interests None.
Ethics approval The Netherlands Twin Register has received ethical approval from the VU University Medical Ethics Committee.
Provenance and Peer review Not commissioned; externally peer reviewed.