Effect of Genetic and Environmental Factors on Writing Development

ABSTRACT

Researchershaveidentifiedsourcesofindividualdifferencesinwritingacrossbeginninganddevelopingwriters. Theaimofthepresentstudywastofurtherclarifythesourcesofthisvariabilitybyinvestigatingtheextentto whichtherearedifferencesingeneticandenvironmentalfactorsunderlyingtheassociationsbetweenlexical diversity,syntacticknowledge,andsemanticcohesionknowledgeinrelationtowriting.Differenceswereexaminedacrosstwodevelopmentalphasesofwriting:beginning(i.e.,elementaryschool)anddeveloping(i.e., middleschool).Participantsincluded262twinpairs(Mage=10.88years)inelementaryschooland247twin pairs(Mage=13.21years)inmiddleschool.TwinsweredrawnfromtheFloridaTwinProjectonReading, Behavior,andEnvironment.Biometricmodelswereconductedseparatelyforsubgroupsdefinedbyphaseof writingdevelopment.Resultsindicatedsignificantetiologicaldifferencesinwritingcomponentsacrossthetwo phases,suchthateffectsassociatedwithgenesandnon-sharedenvironmentweregreaterwhileeffectsassociated withsharedenvironmentwerelowerindevelopingwritersascomparedtobeginningwriters.Furthermore, resultsshowedthatchild-specificenvironmentwasthelargestcontributortoindividualdifferencesinwriting componentsandtheircovariationforbothbeginninganddevelopingwriters.Theseresultsimplythateven directinstructionaboutwritinginschoolsmaybehavingdifferenteffectsonchildrenbasedontheirunique experiences

Keywords: Writing, Etiology, Developmentaldifferences, Twins