Maria Grazia Tosto1, Gabrielle Garon-Carrier2, Susan Gross3, Stephen A Petrill4, Sergey Malykh1,5, Karim Malki6, Sara A Hart7, Lee Thompson3, Rezhaw L Karadaghi6, Nikita Yakovlev1, Tatiana Tikhomirova5, John E Opfer4, Michèle M M Mazzocco8, Ginette Dionne2, Mara Brendgen9, Frank Vitaro10, Richard E Tremblay1,10,11, Michel Boivin1,2, Yulia Kovas1,6,12. 1. Laboratory for Cognitive Investigations and Behavioral Genetics, Department of Psychology, Institute of Genetic, Neurobiological, and Social Foundations of Child Development, Tomsk State University, Tomsk, Oblast, Russia. 2. School of Psychology, Université Laval, Québec City, Québec, Canada. 3. Department of Psychological Sciences, Case Western Reserve University, Cleveland, Ohio, USA. 4. Department of Psychology, The Ohio State University, Columbus, Ohio, USA. 5. Psychological Institute, Russian Academy of Education, Moscow, Russia. 6. MRC Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, Psychology& Neuroscience, King's College London, UK. 7. Department of Psychology, Florida Center for Reading Research, The Florida State University, Tallahassee, Florida, USA. 8. Institute of Child Development, University of Minnesota, Minneapolis, Minnesota, USA. 9. Department of Psychology, School of Psychology, Université du Québec à Montréal, Québec, Canada. 10. Department of Psychoeducation, Department of Pediatrics and Psychology, Université de Montréal, Québec, Canada. 11. School of Public Health, Physiotherapy and Sports Science, University College Dublin, Belfield, Dublin 4, Ireland. 12. Department of Psychology, University of London, UK.
Abstract
BACKGROUND: The number line task assesses the ability to estimate numerical magnitudes. People vary greatly in this ability, and this variability has been previously associated with mathematical skills. However, the sources of individual differences in number line estimation and its association with mathematics are not fully understood. AIMS: This large-scale genetically sensitive study uses a twin design to estimate the magnitude of the effects of genes and environments on: (1) individual variation in number line estimation and (2) the covariation of number line estimation with mathematics. SAMPLES: We used over 3,000 8- to 16-year-old twins from the United States, Canada, the United Kingdom, and Russia, and a sample of 1,456 8- to 18-year-old singleton Russian students. METHODS: Twins were assessed on: (1) estimation of numerical magnitudes using a number line task and (2) two mathematics components: fluency and problem-solving. RESULTS: Results suggest that environments largely drive individual differences in number line estimation. Both genes and environments contribute to different extents to the number line estimation and mathematics correlation, depending on the sample and mathematics component. CONCLUSIONS: Taken together, the results suggest that in more heterogeneous school settings, environments may be more important in driving variation in number line estimation and its association with mathematics, whereas in more homogeneous school settings, genetic effects drive the covariation between number line estimation and mathematics. These results are discussed in the light of development and educational settings.
BACKGROUND: The number line task assesses the ability to estimate numerical magnitudes. People vary greatly in this ability, and this variability has been previously associated with mathematical skills. However, the sources of individual differences in number line estimation and its association with mathematics are not fully understood. AIMS: This large-scale genetically sensitive study uses a twin design to estimate the magnitude of the effects of genes and environments on: (1) individual variation in number line estimation and (2) the covariation of number line estimation with mathematics. SAMPLES: We used over 3,000 8- to 16-year-old twins from the United States, Canada, the United Kingdom, and Russia, and a sample of 1,456 8- to 18-year-old singleton Russian students. METHODS: Twins were assessed on: (1) estimation of numerical magnitudes using a number line task and (2) two mathematics components: fluency and problem-solving. RESULTS: Results suggest that environments largely drive individual differences in number line estimation. Both genes and environments contribute to different extents to the number line estimation and mathematics correlation, depending on the sample and mathematics component. CONCLUSIONS: Taken together, the results suggest that in more heterogeneous school settings, environments may be more important in driving variation in number line estimation and its association with mathematics, whereas in more homogeneous school settings, genetic effects drive the covariation between number line estimation and mathematics. These results are discussed in the light of development and educational settings.
Authors: Yulia Kovas; Eduard V Galajinsky; Michel Boivin; Gordon T Harold; Alice Jones; Jean-Pascal Lemelin; Yu Luo; Stephen A Petrill; Robert Plomin; Tatiana Tikhomirova; Xinlin Zhou; Sergey Malykh Journal: Twin Res Hum Genet Date: 2012-12-13 Impact factor: 1.587