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Twins were assessed through a 90-min home visit at approximately age 10 and were reassessed in their homes approximately 1 year later. Results suggested that the shared environment and genetics influenced the covariance among math fluency, untimed math measures, and reading measures. However, roughly two thirds of the variance in math fluency was independent from untimed math measures and reading, including reading fluency. The majority of this independent variance was the result of genetic factors that were longitudinally stable across two measurement occasions. These results suggest that math fluency, although related to other math measures, may also be a genetically distinct dimension of mathematics performance.<\/jats:p>","DOI":"10.1177\/0022219411407926","type":"journal-article","created":{"date-parts":[[2011,9,3]],"date-time":"2011-09-03T00:57:57Z","timestamp":1315011477000},"page":"371-381","update-policy":"https:\/\/doi.org\/10.1177\/sage-journals-update-policy","source":"Crossref","is-referenced-by-count":51,"title":["Math Fluency Is Etiologically Distinct From Untimed Math Performance, Decoding Fluency, and Untimed Reading Performance"],"prefix":"10.1177","volume":"45","author":[{"given":"Stephen","family":"Petrill","sequence":"first","affiliation":[{"name":"Ohio State University, Columbus, OH, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jessica","family":"Logan","sequence":"additional","affiliation":[{"name":"Ohio State University, Columbus, OH, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sara","family":"Hart","sequence":"additional","affiliation":[{"name":"Florida State University, Tallahassee, FL, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Pamela","family":"Vincent","sequence":"additional","affiliation":[{"name":"Ohio State University, Columbus, OH, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lee","family":"Thompson","sequence":"additional","affiliation":[{"name":"Case Western Reserve University, Cleveland, OH, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yulia","family":"Kovas","sequence":"additional","affiliation":[{"name":"Institute of Psychiatry, London, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Robert","family":"Plomin","sequence":"additional","affiliation":[{"name":"King\u2019s College London, MRC Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, De Crespigny Park, London, SE5 8AF, United Kingdom"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"179","published-online":{"date-parts":[[2011,9,2]]},"reference":[{"key":"bibr1-0022219411407926","doi-asserted-by":"publisher","DOI":"10.1037\/0022-0663.96.4.699"},{"key":"bibr2-0022219411407926","first-page":"1","volume":"65","author":"Bull R.","year":"1997","journal-title":"Journal of Experimental Psychology"},{"key":"bibr3-0022219411407926","doi-asserted-by":"publisher","DOI":"10.1080\/87565649909540759"},{"key":"bibr4-0022219411407926","volume-title":"The mathematical brain","author":"Butterworth B.","year":"1999"},{"key":"bibr5-0022219411407926","doi-asserted-by":"publisher","DOI":"10.1037\/0022-0663.99.2.369"},{"key":"bibr6-0022219411407926","doi-asserted-by":"publisher","DOI":"10.1111\/j.1750-8606.2008.00072.x"},{"key":"bibr7-0022219411407926","doi-asserted-by":"publisher","DOI":"10.1037\/0022-0663.100.1.30"},{"key":"bibr8-0022219411407926","doi-asserted-by":"publisher","DOI":"10.1177\/001440291007600201"},{"key":"bibr9-0022219411407926","doi-asserted-by":"publisher","DOI":"10.1016\/j.lindif.2009.10.008"},{"key":"bibr10-0022219411407926","doi-asserted-by":"publisher","DOI":"10.1016\/0022-0965(89)90028-3"},{"key":"bibr11-0022219411407926","doi-asserted-by":"publisher","DOI":"10.1037\/0096-3445.116.2.154"},{"key":"bibr12-0022219411407926","doi-asserted-by":"publisher","DOI":"10.1016\/0160-2896(92)90025-M"},{"key":"bibr13-0022219411407926","doi-asserted-by":"publisher","DOI":"10.1007\/BF01065819"},{"key":"bibr14-0022219411407926","doi-asserted-by":"publisher","DOI":"10.1016\/j.lindif.2009.10.004"},{"key":"bibr15-0022219411407926","doi-asserted-by":"publisher","DOI":"10.1037\/a0015115"},{"key":"bibr16-0022219411407926","doi-asserted-by":"publisher","DOI":"10.1006\/jecp.2000.2586"},{"key":"bibr17-0022219411407926","doi-asserted-by":"publisher","DOI":"10.1111\/1540-5826.00076"},{"key":"bibr18-0022219411407926","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1111\/j.1540-5834.2007.00413.x","volume":"72","author":"Kovas Y.","year":"2007","journal-title":"Monographs of the Society for Research in Child Development"},{"key":"bibr19-0022219411407926","doi-asserted-by":"publisher","DOI":"10.1016\/j.cognition.2003.11.004"},{"key":"bibr20-0022219411407926","volume-title":"Peabody Individual Achievement Test\u2013Revised","author":"Markwardt F. 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