Twin Research and Human Genetics

Articles

Developmental Origins of Low Mathematics Performance and Normal Variation in Twins from 7 to 9 Years

Claire M. A. Hawortha1 c1, Yulia Kovasa2, Stephen A. Petrilla3 and Robert Plomina4

a1 Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London, De Crespigny Park, London, United Kingdom. Claire.Haworth@iop.kcl.ac.uk

a2 Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London, De Crespigny Park, London, United Kingdom.

a3 Department of Human Development and Family Science, Ohio State University, Columbus, Ohio, United States of America.

a4 Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London, De Crespigny Park, London, United Kingdom.

Abstract

A previous publication reported the etiology of mathematics performance in 7-year-old twins (Oliver et al., 2004). As part of the same longitudinal study we investigated low mathematics performance and normal variation in a representative United Kingdom sample of 1713 same-sex 9-year-old twins based on teacher-assessed National Curriculum standards. Univariate individual differences and DeFries-Fulker extremes analyses were performed. Similar to our results at 7 years, all mathematics scores at 9 years showed high heritability (.62–.75) and low shared environmental estimates (.00–.11) for both the low performance group and the full sample. Longitudinal analyses were performed from 7 to 9 years. These longitudinal analyses indicated strong genetic continuity from 7 to 9 years for both low performance and mathematics in the normal range. We conclude that, despite the considerable differences in mathematics curricula from 7 to 9 years, the same genetic effects largely operate at the two ages.

(Received October 12 2006)

(Accepted October 17 2006)

Correspondence:

c1 Address for correspondence: Claire Haworth, SGDP Centre, Institute of Psychiatry, King's College London, De Crespigny Park, London SE5 8AF, UK.

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