ABSTRACT

Over30yearsago,Shankweiler,Liberman,andtheircolleaguesatHaskins Laboratoriesintroducedthephonologicaldeˆcithypothesistoaccountfor the problems some children have in learning to read and spell (Liberman & Shankweiler,1979;Shankweiler,Liberman,Mark,Fowler,&Fischer,1979). Although others had offered somewhat similar proposals (e.g., Calfee, Chapman, & Venezky,1972),theHaskinsgroupwastheˆrsttofullyarticulateandinvestigate thisview.Theyarguedthatindividualdifferencesinchildren’sabilitytolearn to read and spell were the result of variability in children’s representation of the speechcodesonwhichwrittenlanguagesarebased.Intheyearssince,alarge bodyofworkhasaccumulatedinsupportofthishypothesis.Thisworkhasshown thataphonologicaldeˆcitcanaccountforproblemsinlearningtoreadinavarietyoflanguagesinvolvingavarietyoforthographies(Fletcheretal.,1994;Ho, Law, & Ng, 2000; H. Lyytinen et al., 2004; Stanovich & Siegel, 1994). Research hasfurtherrevealedaneurologicalandgeneticbasisforindividualdifferences inphonologicalprocessingability*(Byrneetal.,2002;Simos,Brier,Fletcher, Bergman, & Papanicolauo, 2002).