Children with and without Family Risk of Reading difficulties: Emergent literacy, home literacy environment at onset of formal reading instruction, and literacy skills after two years of schooling
Keywords:
family risk, reading difficulties, impaired emergent literacy, home literacy environment, literacy, literacy skillsSynopsis
Having a parent with reading difficulties, known as family risk, puts a child at high risk of impaired emergent literacy before the onset of reading instruction, and later reading difficulties at school. Another line of research, however, highlights that environmental factors such as the quality and quantity of what parents provide at home (home literacy environment) are also crucial for the development of children’s emergent literacy and later literacy skills. This thesis used a multi-factor perspective on reading difficulties to investigate the associations between family risk, emergent literacy, the home literacy environment at the onset of formal reading instruction and literacy skills after two years of schooling. Such a multi-factor perspective may combine a range of interplaying factors, including family risk along with early individual differences at the cognitive level (emergent literacy skills) and environmental factors (parents’ educational level and the home literacy environment) to assess the protective role of environmental factors against the risk factors such as family risk.
Data from ‘On Track’ project (på sporet) were used in analysis of three empirical studies. Children were individually assessed in emergent literacy at the onset of reading instruction. At this point, parents’ selfreport of reading difficulties were used to index family risk, and the home literacy environment was measured through parental reporting. In addition, children were assessed in literacy measures including word reading, spelling and reading comprehension at the end of second grade.
The first study showed that children with family risk were significantly impaired on all measures of emergent literacy (letter knowledge and phonemic awareness), vocabulary, rapid automatized naming and shortterm memory at the onset of formal reading instruction. A novel finding was that a significant difference in emergent literacy within the group of children with family risk as apparent before the onset of reading instruction: Children with family risk who both of parents reported reading difficulties, had significantly poorer emergent literacy than both groups of children with only one parent reporting reading difficulties, and children with no family risk. Furthermore, family risk, in a multifactor model, was significantly associated with children’s emergent literacy above and beyond the home literacy environment, the child’s gender, vocabulary, and the parents’ educational level.
The main aim of the second study was to investigate children’s reading difficulties in a multi-factor perspective after two years of formal schooling. Children who performed below the national threshold in at least two of the subtests in reading, spelling and comprehension were identified as having reading difficulties. The results revealed that children with family risk were three times more likely to develop reading difficulties than children without such a risk. The multi-factor model also suggested that children with family risk showed some difficulties in literacy skills that could not be explained in terms of individual differences in emergent literacy, vocabulary, gender, the home literacy environment or parents’ educational level.
The main aim of the third study was to investigate the role of protective environmental factors (e.g., home literacy environment and parents’ education) against the negative effect of family risk, in children’s emergent literacy skills at the onset of formal reading instruction. First, a model of home literacy environment was assessed and three distinct factors were identified: access to print, reading-related activities and parents’ reading interest and habits. In a structural equation model, maternal and paternal self-report of RD (as a proxy for family risk) along with their educational level were added as direct and indirect predictors of children’s emergent literacy while accounting for the home literacy environment. The results suggest that family risk explain some additional variance in emergent literacy that cannot be explained by parents’ educational level and the home literacy environment. However, and perhaps more importantly, this multi-factor model highlights a complex interplaying role for the relationship between family risk and environmental protective factors (the home literacy environment and parents’ education) in association with children’s emergent literacy skills. Therefore, the protective role of environmental factors on emergent literacy skills against the negative influence of family risk cannot be ruled out in children with family risk of reading difficulties.
Taken together, the findings presented in this thesis reveal that the association between family risk, children’s emergent literacy and their literacy skills is indeed a complex relationship, which involves with environmental factors. It seems that children’s emergent literacy and later literacy skills and their literacy experiences in the home environments may not be independent of family risk. However, a high parents’ educational level and a rich home literacy environment appear to operate as protective factors against a risk factor such as family risk. These findings suggest there are reasons to believe that it is possible to change and reduce the influence of family risk through environmental protective factors such as a rich home literacy environment.
References
American Psychiatric Association. (2013). In Diagnostic and statistical manual of mental disorders (Vol. 5th): Washington, DC.
https://doi.org/10.1176/appi.books.9780890425596
Aro, T., Poikkeus, A. M., Eklund, K., Tolvanen, A., Laakso, M. L., Viholainen, H., . . . Ahonen, T. (2009). Effects of multidomain risk accumulation on cognitive, academic, and behavioural outcomes. Journal of Clinical Child & Adolescent Psychology, 38(6), 883-898.
https://doi.org/10.1080/15374410903258942
Baker, L., & Scher, D. (2002). Beginning readers' motivation for reading in realation to parental beliefs and home reading experiences. Reading Psychology, 23(4), 239-269.
https://doi.org/10.1080/713775283
Brown, T. A. (2006). Confirmatory factor analysis for applied research (Second ed.). New York: Guilford Publications.
Burgess, S. R., Hecht, S. A., & Lonigan, C. J. (2002). Relations of the home literacy environment (HLE) to the development of reading-related abilities: A one-year longitudinal study. Reading Research Quarterly, 37(4), 408-426.
https://doi.org/10.1598/RRQ.37.4.4
Bus, A. G., van Ijzendoorn, M. H., & Pellegrini, A. D. (1995). Joint book reading makes for success in learning to read: A meta-analysis on intergenerational transmission of literacy. Review of Educational Research, 65(1), 1-21.
https://doi.org/10.3102/00346543065001001
Byrne, B., Olson, R. K., Samuelsson, S., Wadsworth, S., Corley, R., DeFries, J. C., & Willcutt, E. (2006). Genetic and environmental influences on early literacy. Journal of Research in Reading, 29(1), 33-49.
https://doi.org/10.1111/j.1467-9817.2006.00291.x
Byrne, B., Wadsworth, S., Boehme, K., Talk, A. C., Coventry, W. L., Olson, R. K., . . . Corley, R. (2013). Multivariate Genetic Analysis of Learning and Early Reading Development. Scientific Studies of Reading, 17(3), 224-242.
https://doi.org/10.1080/10888438.2011.654298
Cardoso-Martins, C., & Pennington, B. F. (2004). The relationship between phoneme awareness and rapid serial naming skills and literacy acquisition: The role of developmental period and reading ability. Scientific Studies of Reading, 8(1), 27-52.
https://doi.org/10.1207/s1532799xssr0801_3
Carroll, J. M., Mundy, I. R., & Cunningham, A. J. (2014). The roles of family history of dyslexia, language, speech production and phonological processing in predicting literacy progress. Developmental Science, 17(5), 727-742.
https://doi.org/10.1111/desc.12153
Carroll, J. M., & Snowling, M. J. (2004). Language and phonological skills in children at high risk of reading difficulties. Journal of Child Psychology and Psychiatry, 45(3), 631-640.
https://doi.org/10.1111/j.1469-7610.2004.00252.x
Christopher, M. E., Hulslander, J., Byrne, B., Samuelsson, S., Keenan, J. M., Pennington, B. F., . . . Olson, R. K. (2013). Modeling the Etiology of Individual Differences in Early Reading Development: Evidence for Strong Genetic Influences. Scientific Studies of Reading, 17(5), 350-368.
https://doi.org/10.1080/10888438.2012.729119
Coventry, W. L., Byrne, B., Olson, R. K., Corley, R., & Samuelsson, S. (2011). Dynamic and Static Assessment of Phonological Awareness in Preschool: A Behavior-Genetic Study. Journal of LearningDisability, 44(4), 322-329.
https://doi.org/10.1177/0022219411407862
DeThorne, L.S., Hart, S. A., Petrill, S. A., Deater-Deckard, K., Thompson, L. A., Schatschneider, C., & Davison, M. D. (2006). Children's history of speech-language difficulties: Genetic influences and associations with reading-related measures. Journal of Speech, Language, and Hearing Research, 49(6), 1280-1293.
https://doi.org/10.1044/1092-4388(2006/092)
Dickinson, D. K., & Sparague, K. E. (2001). The nature and impact of early childhood care environments on the language and early literacy development of children from low-income families. In S. B. Neuman & D. K. Dickinson (Eds.), Handbook of early literacy research (Vol. 1, pp. 263-280). New York, NY: The Guilford Press.
Dilnot, J., Hamilton, L., Maughan, B., & Snowling, M. J. (2016). Child and environmental risk factors predicting readiness for learning in children at high risk of dyslexia. Development and psychopathology, 1-10.
https://doi.org/10.1017/S0954579416000134
Dilnot, J., Hamilton, L., Maughan, B., & Snowling, M. J. (2017). Child and environmental risk factorspredicting readiness for learning in children at high risk of dyslexia. Development and psychopathology, 29(1), 235-244.
https://doi.org/10.1017/S0954579416000134
Elbro, C., Borstrom, I., & Petersen, D. K. (1998). Predicting dyslexia from kindergarten: The importance of distinctness of phonological representations of lexical items. Reading Research Quarterly, 33(1), 36-60.
https://doi.org/10.1598/RRQ.33.1.3
Elbro, C., Borstrøm, I., & Petersen, D. K. (1998). Predicting dyslexia from kindergarten: The importance of distinctness of phonological representations of lexical items. Reading Research Quarterly, 33(1), 36-60.
https://doi.org/10.1598/RRQ.33.1.3
Elbro, C., & Petersen, D. K. (2004). Long-term effects of phoneme awareness and letter sound training: An intervention study with children at risk for dyslexia. Journal of EducationalPsychology, 96(4), 660.
https://doi.org/10.1037/0022-0663.96.4.660
Elwér, Å., Keenan, J. M., Olson, R. K., Byrne, B., & Samuelsson, S. (2013). Longitudinal stability and predictors of poor oral comprehenders and poor decoders. Journal of Experimental Child Psychology, 115(3), 497-516.
https://doi.org/10.1016/j.jecp.2012.12.001
Esmaeeli, Z., Lundetrae, K., & Kyle, F. E. (2018). What can Parents' Self-report of Reading Difficulties Tell Us about Their Children's EmergentLiteracy at School Entry? Dyslexia, 24(1), 84-105.
https://doi.org/10.1002/dys.1571
Evans, M. A., Shaw, D., & Bell, M. (2000). Home literacy activities and their influence on early literacy skills. Canadian Journal of Experimental Psychology/Revue canadienne de psychologie expérimentale, 54(2), 65.
https://doi.org/10.1037/h0087330
Fletcher, J. M., Lyon, G. R., Fuchs, L. S., & Barnes, M. A. (2007). Learning Disabilities: From Identification to Intervention. New York: Guilford Press.
Friend, A., DeFries, J. C., Olson, R. K., Pennington, B. F., Harlaar, N., Byrne, B., . . . Keenan, J. M. (2009). Heritability of High Reading Ability and its Interaction with Parental Education. Behavior Genetics, 39(4), 427-436.
https://doi.org/10.1007/s10519-009-9263-2
Frijters, J. C., Barron, R. W., & Brunello, M. (2000). Direct and mediated influences of home literacy and literacy interest on prereaders' oral vocabulary and early written language skill. Journal of Educational Psychology, 92(3), 466.
https://doi.org/10.1037/0022-0663.92.3.466
Furnes, B., &Samuelsson, S. (2010). Predicting Reading and Spelling Difficulties in Transparent and Opaque Orthographies: A Comparison between Scandinavian and US/Australian Children. Dyslexia, 16(2), 119-142.
https://doi.org/10.1002/dys.401
Gallagher, A., Frith, U., & Snowling,M. J. (2000). Precursors of literacy delay among children at genetic risk of dyslexia. Journal of Child Psychology and Psychiatry, 41(2), 203-213.
https://doi.org/10.1111/1469-7610.00601
Hamilton, L., Hayiou-Thomas, M. E., Hulme, C., & Snowling, M. J. (2016). The home literacy environment as a predictor of the early literacy development of children at family-risk of dyslexia. Scientific Studies of Reading, 20(5), 401-419.
https://doi.org/10.1080/10888438.2016.1213266
Harlaar, N., Spinath, F. M., Dale, P. S., & Plomin, R. (2005). Genetic influences on early wordrecognition abilities and disabilities: a study of 7-year-old twins. Journal of Child Psychology and Psychiatry, 46(4), 373-384.
https://doi.org/10.1111/j.1469-7610.2004.00358.x
Hart, S. A., Ganley, C. M., & Purpura, D. J. (2016). Understanding the Home Math Environment and Its Role in Predicting Parent Report of Children's Math Skills. PloS one, 11(12), e0168227.
https://doi.org/10.1371/journal.pone.0168227
Hart, S. A., Logan, J. A. R., Soden-Hensler, B., Kershaw, S., Taylor, J., & Schatschneider, C. (2013). Exploring how nature and nurture affect the development of reading: an analysis of the Florida Twin Project on reading. Developmental Psychology, 49(10), 1971.
https://doi.org/10.1037/a0031348
Hart, S. A., Petrill, S. A., DeThorne, L. S., Deater-Deckard, K., Thompson, L. A., Schatschneider, C., & Cutting, L. E. (2009). Environmental influences on the longitudinal covariance of expressive vocabulary: measuring the home literacy environment in a genetically sensitive design. Journal of Child Psychology and Psychiatry, 50(8), 911-919.
https://doi.org/10.1111/j.1469-7610.2009.02074.x
Hart, S. A., Soden-Hensler, B., Johnson, W., Schatschneider, C., & Taylor, J. (2013) Expanding the environment: genex school-level SES interaction on reading comprehension. Journal of Child Psychology and Psychiatry, 54(10), 1047-1055.
https://doi.org/10.1111/jcpp.12083
Hayiou-Thomas, M. E. (2008). Genetic and environmental influences on early speech, language and literacy development. Journal of Communication Disorders, 41(5), 397-408.
https://doi.org/10.1016/j.jcomdis.2008.03.002
Karrass, J., VanDeventer, M. C., & Braungart-Rieker, J. M. (2003). Predicting shared parent-child book reading in infancy. Journal of Family Psychology, 17(1), 134. Leavett, R., Nash, H. M., & Snowling, M. J. (2014). Am I dyslexic? Parental self-report of literacy difficulties. Dyslexia, 20(4), 297-304.
https://doi.org/10.1002/dys.1481
Lefly, D. L., & Pennington, B. F. (2000). Reliability and validity of the adult reading history questionnaire. Journal of Learning Disability, 33(3), 286-296.
https://doi.org/10.1177/002221940003300306
Leinonen, S., Müller, K., Leppänen, P. H. T., Aro, M., Ahonen, T., & Lyytinen, H. (2001). Heterogeneity in adult dyslexic readers: Relating processing skills to the speed and accuracy of oral text reading. Reading and Writing, 14(3), 265-296.
https://doi.org/10.1023/A:1011117620895
Levy, B. A., Gong, Z., Hessels, S., Evans, M. A., & Jared, D. (2006). Understanding print: Early reading development and the contributions of home literacy experiences. Journal of Experimental Child Psychology, 93(1), 63-93. Lonigan, C. J. (1994). Reading to preschoolers exposed: Is the emperor really naked? Developmental Review, 14(3), 303-323.
https://doi.org/10.1016/j.jecp.2005.07.003
Lonigan, C. J., Burgess, S. R., & Anthony, J. L. (2000). Development of emergent literacy and early reading skills in preschool children: Evidence from a latent-variable longitudinal study. Developmental Psychology, 36(5), 596-613.
https://doi.org/10.1037/0012-1649.36.5.596
Lonigan, C. J., Burgess, S. R., Anthony, J. L., & Barker, T. A. (1998). Development of phonological sensitivity in 2- to 5-year-old children. Journal of Educational Psychology, 90(2), 294-311.
https://doi.org/10.1037/0022-0663.90.2.294
Lonigan, C. J., Schatschneider, C., & Westberg, L. (2008). Identification of Children's Skills and Abilities Linked to Later Outcomes in Reading, Writing, and Spelling. Developing early literacy: Report of the national early literacy panel, 55-107.
Lovett, M. W., Frijters, J. C., Wolf, M., Steinbach, K. A., Sevcik, R. A. & Morris, R. D. (2017). Early Intervention for Children at Risk for Reading Disabilities: The Impact of Grade at Intervention and Individual Differences on Intervention Outcomes. Journal of Educational Psychology.
https://doi.org/10.1037/edu0000181
Lundetræ, K., Solheim, O. J., Schwippert, K., & Uppstad, P. H. (2017). Protocol: 'On Track', a group-randomized controlled trial of an early reading intervention. International Journal of Educational Research.
https://doi.org/10.1016/j.ijer.2017.08.011
Lyytinen, H., Ahonen, T., Eklund, K., Guttorm, T., Kulju, P., Laakso, M. L., . . . Viholainen, H. (2004). Early development of children at familial risk for dyslexia: follow-up from birth to school age. Dyslexia, 10(3), 146-178.
https://doi.org/10.1002/dys.274
Lyytinen, H., Aro, M., Eklund, K., Erskine, J., Guttorm, T., Laakso, M. L., . . . Torppa, M. (2004). The development of children at familial risk for dyslexia: birth to early school age. Annuals of Dyslexia, 54(2), 184-220.
https://doi.org/10.1007/s11881-004-0010-3
Løken, K. V. (2010). Family income and children's education: Using the Norwegian oil boom as a natural experiment. Labour Economics, 17(1), 118-129.
https://doi.org/10.1016/j.labeco.2009.06.002
Muthén, L. K., & Muthén, B. O. (2017). Mplus User's Guide (Eighth Edition ed.). Los Angeles, CA: Muthén & Muthén.
Nash, H. M., Hulme, C., Gooch, D., & Snowling, M. J. (2013). Preschool language profiles of children at family risk of dyslexia: continuities with specific language impairment. Journal ofChild Psychology and Psychiatry, 54(9), 958-968.
https://doi.org/10.1111/jcpp.12091
Niklas, F., Cohrssen, C., & Tayler, C. (2016). Parents Supporting Learning: A Non-Intensive Intervention Supporting Literacy and Numeracy in the Home Learning Environment. International Journal of Early Years Education, 24(2), 121-142.
https://doi.org/10.1080/09669760.2016.1155147
Niklas, F., & Schneider, W. (2013). Home literacy environment and the beginning of reading and spelling. Contemporary Educational Psychology, 38(1), 40-50.
https://doi.org/10.1016/j.cedpsych.2012.10.001
Niklas, F., & Schneider, W. (2015). With a little help: improving kindergarten children's vocabulary by enhancing the home literacy environment. Reading and Writing, 28(4), 491-508.
https://doi.org/10.1007/s11145-014-9534-z
Pennington, B. F. (2006). From single to multiple deficit models of developmental disorders. Cognition, 101(2), 385-413.
https://doi.org/10.1016/j.cognition.2006.04.008
Pennington, B.F., Cardoso-Martins, C., Green, P. A., & Lefly, D. L. (2001). Comparing the phonological and double deficit hypotheses for developmental dyslexia. Reading and Writing, 14(7), 707-755.
https://doi.org/10.1023/A:1012239018038
Pennington, B. F., & Lefly, D. L. (2001). Early reading development in children at family risk for dyslexia. Child Development, 72(3), 816-833.
https://doi.org/10.1111/1467-8624.00317
Pennington, B. F., Lemmon, L. S., Rosenberg, J., MacDonald, B., Boada, R., Friend, A., . . . Olson, R. K. (2012). Individual Prediction of Dyslexia by Single Versus Multiple Deficit Models. Journal of Abnormal Psychology, 121(1), 212-224.
https://doi.org/10.1037/a0025823
Phillips, B. M., & Lonigan, C. J. (2009). Variations in the Home Literacy Environment of Preschool Children: A Cluster Analytic Approach. Scientific Studies of Reading, 13(2), 146-174.
https://doi.org/10.1080/10888430902769533
Puglisi, M. L., Hulme, C., Hamilton, L., & Snowling, M. J. (2017). The home literacy environment is a correlate, but perhaps not a cause, of variations in children's language and literacy development. Scientific Studies of Reading, 1-17.
https://doi.org/10.1080/10888438.2017.1346660
Puolakanaho, A., Ahonen, T., Aro, M., Eklund, K., Leppänen, P. H. T., Poikkeus, A. M., . . . Lyytinen, H. (2007). Very early phonological and language skills: estimating individual risk of reading disability. Journal of Child Psychology and Psychiatry, 48(9), 923-931.
https://doi.org/10.1111/j.1469-7610.2007.01763.x
Raz, I. S., & Bryant, P. (1990). Social background, phonological awareness and children's reading. British Journal of Developmental Psychology, 8(3), 209-225.
https://doi.org/10.1111/j.2044-835X.1990.tb00837.x
Samuelsson, S., Byrne, B., Olson, R. K., Hulslander, J., Wadsworth, S., Corley, R., . . . DeFries, J. C. (2008). Response to early literacy instruction in the United States, Australia, and Scandinavia: A behavioral-genetic analysis. Learning and Individual Differences, 18(3), 289-295.
https://doi.org/10.1016/j.lindif.2008.03.004
Samuelsson, S., Byrne, B., Quain, P., Wadsworth, S., Corley, R., DeFries, J. C., . . . Olson, R. K. (2005). Environmental and genetic influences on prereading skills in Australia, Scandinavia, and the United States. Journal of EducationalPsychology,97(4), 705-722.
https://doi.org/10.1037/0022-0663.97.4.705
Samuelsson, S., & Lundberg, I. (2003). The impact of environmental factors on components of reading and dyslexia. Annuals of Dyslexia, 53, 201-217.
https://doi.org/10.1007/s11881-003-0010-8
Samuelsson, S., Olson, R. K., Wadsworth, S., Corley, R., DeFries, J. C., Willcutt, E., . . . Byrne, B. (2007). Genetic and environmental influences on prereading skills and early reading and spelling development in the United States, Australia, and Scandinavia. Reading and Writing, 20(1-2), 51-75.
https://doi.org/10.1007/s11145-006-9018-x
Scarborough, H. S. (1990). Very Early Language Deficits in Dyslexic- Children. Child Development, 61(6), 1728-1743.
https://doi.org/10.1111/j.1467-8624.1990.tb03562.x
Scarborough, H. S. (1991). Antecedents to Reading-Disability - Preschool Language-Development and Literacy Experiences of Children from Dyslexic Families. Reading and Writing, 3(3-4), 219-233.
https://doi.org/10.1007/BF00354959
Scarborough, H. S. (2001). Connecting early language and literacy to later reading (dis)abilities: evidence, theory, and practice. In S. B. Neuman & D. K. Dickinson (Eds.), Handbook of early literacy research (pp. 97-110). NY: Guilford Press.
Scarborough, H. S., & Dobrich, W. (1994). On the Efficacy of Reading to Preschoolers. Developmental Review, 14(3), 245-302.
https://doi.org/10.1006/drev.1994.1010
Scarborough, H. S., Dobrich, W., & Hager, M. (1991). Preschool Literacy Experience and Later Reading-Achievement. Journal of Learning Disabilities, 24(8), 508-511.
https://doi.org/10.1177/002221949102400811
Sénéchal, M. (1997). The differential effect of storybook reading on preschoolers' acquisition of expressive and receptive vocabulary. Journal of Child language, 24(1), 123-138.
https://doi.org/10.1017/S0305000996003005
Sénéchal, M. (2006). Testing the home literacy model: Parent involvement in kindergarten is differentially related to grade 4 reading comprehension, fluency, spelling, and reading for pleasure. Scientific Studies of Reading, 10(1), 59-87.
https://doi.org/10.1207/s1532799xssr1001_4
Sénéchal, M. (2011). A model of the concurrent and longitudinal relations between home literacy and child outcomes. In Handbook of early literacy research (Vol. 3, pp. 175-188).
Sénéchal, M., & LeFevre, J. A. (2001). Storybook reading and parent teaching: Links to language and literacy development. New Directions for Child and Adolescent Development, 2001(92), 39-52.
Sénéchal, M., & LeFevre, J. A. (2002). Parental involvement in the development of children's reading skill: A five-year longitudinal study. Child Development, 73(2), 445-460.
https://doi.org/10.1111/1467-8624.00417
Sénéchal, M., & LeFevre, J. A. (2014). Continuityand change in the home literacy environment as predictors of growth in vocabulary and reading. Child Development, 85(4), 1552-1568.
https://doi.org/10.1111/cdev.12222
Sénéchal, M., Lefevre, J. A., Thomas, E. M., & Daley, K. E. (1998). Differential effects of home literacy experiences on the development of oral and written language. Reading Research Quarterly, 33(1), 96-116.
https://doi.org/10.1598/RRQ.33.1.5
Sénéchal, M., & Young, L. (2008). The effect of family literacy interventions on children's acquisition of reading from kindergarten to grade 3: A meta-analytic review. Review of Educational Research, 78(4), 880-907.
https://doi.org/10.3102/0034654308320319
Shadish, W. R., Cook, T. D., & Campbell, D. T. (2002). Experimental and quasi-experimental designs for generalized causal inference. Boston, MA, US: Houghton, Mifflin and Company.
Snowling, M. J., Dawes, P., Nash, H., & Hulme, C. (2012). Validity of a protocol for adult self-report of dyslexia and related difficulties. Dyslexia, 18(1), 1-15.
https://doi.org/10.1002/dys.1432
Snowling, M. J., Gallagher, A., & Frith, U. (2003). Family risk of dyslexia is continuous: Individual differences in the precursors of reading skill. Child Development, 74(2), 358-373.
https://doi.org/10.1111/1467-8624.7402003
Snowling, M. J., & Melby-Lervåg, M. (2016). Oral language deficits in familial dyslexia: A meta-analysis and review. Psychological Bulletin, 142(5), 498-545.
https://doi.org/10.1037/bul0000037
Snowling, M. J., Muter, V., & Carroll, J. M. (2007). Children at family risk of dyslexia: a follow-up in early adolescence. Journal of Child Psychology andPsychiatry, 48(6), 609-618.
https://doi.org/10.1111/j.1469-7610.2006.01725.x
Stanovich, K. E., & Siegel, L. S. (1994). Phenotypic performance profile of children with reading disabilities: A regression-based test of the phonological-core variable-difference model. Journal of Educational Psychology, 86(1), 24.
https://doi.org/10.1037/0022-0663.86.1.24
Størksen, I., Ellingsen, I. T., Tvedt, M. S., & Idsøe, E. M. (2013). Norsk vokabulartest(NVT) for barn i overgangen mellom barnehage og skole. Psykometrisk vurdering av en nettbrettbasert test. Spesialpedagogikks forskningsdel, 4(13), 40-54.
Tabachnick, B. G., & Fidell, L. S. (2007). Using multivariate statistics, Boston, MC: Pearson Education.
Taylor, J., & Schatschneider, C. (2010). Genetic Influence on Literacy Constructs in Kindergarten and First Grade: Evidence from a Diverse Twin Sample. Behavior Genetics, 40(5), 591-602.
https://doi.org/10.1007/s10519-010-9368-7
Torgesen, J. K. (2002). Lessons learned from intervention research in reading: A way to go before we rest. R. Stainthorp and P.
Tomlinson (Edn.). Learning and Teaching Reading. British Journal of Educational Psychology, Monograph Series II: Psychological Aspects of Education-Current Trends, 1, 89-104.
Torppa, M., Eklund, K., van Bergen, E., & Lyytinen, H. (2011). Parental Literacy Predicts Children's Literacy: A Longitudinal Family-Risk Study. Dyslexia,17(4), 339-355.
https://doi.org/10.1002/dys.437
Torppa, M., Lyytinen, P., Erskine, J., Eklund, K., & Lyytinen, H. (2010). Language development, literacy skills, and predictive connections to reading in Finnish children with and without familial risk for dyslexia. Journal of Learning Disabilities, 43(4), 308-321.
https://doi.org/10.1177/0022219410369096
Torppa, M., Poikkeus, A.-M., Laakso, M.-L., Tolvanen, A., Leskinen, E., Leppanen, P. H. T., . . . Lyytinen, H. (2007a). Modeling the Early Paths of Phonological Awareness and Factors Supporting its Development in Children With and Without Familial Risk of Dyslexia. Scientific Studies of Reading, 11(2), 73-103.
https://doi.org/10.1080/10888430709336554
Torppa, M., Poikkeus, A. M., Laakso, M. L., Eklund, K., & Lyytinen, H. (2006). Predicting delayed letter knowledge development and its relation to grade 1 reading achievement among children with and without familial risk for dyslexia. DevelopmentalPsychology, 42(6), 1128-1142.
https://doi.org/10.1037/0012-1649.42.6.1128
Torppa, M., Poikkeus, A. M., Laakso, M. L., Tolvanen, A., Leskinen, E., Leppanen, P. H. T., . . . Lyytinen, H. (2007b). Modeling the Early Paths of Phonological Awareness and Factors Supporting its Development in Children With and Without Familial Risk of Dyslexia. Scientific Studies of Reading, 11(2), 73-103.
https://doi.org/10.1080/10888430709336554
Utdanningsdirektoratet. (2016). The Education Mirror provides facts and analyses of kindergartens, primary and secondary education in Norway. Retrieved from http://utdanningsspeilet.udir.no/2016/en/content/chapter-2/2-1-pupil-and-school-numbers/
van Bergen, E., Bishop, D., van Zuijen, T., & de Jong, P. F. (2015). How does parental reading influence children's reading? A study of cognitive mediation. Scientific Studies of Reading, 19(5), 325-339.
https://doi.org/10.1080/10888438.2015.1050103
van Bergen, E., de Jong, P. F., Maassen, B., & van der Leij, A. (2014a). The effect of parents' literacy skills and children's preliteracy skills on the risk of dyslexia. Journal of abnormal child psychology, 42(7), 1187-1200.
https://doi.org/10.1007/s10802-014-9858-9
van Bergen, E., de Jong, P. F., Plakas, A., Maassen, B., & van der Leij, A. (2012). Child and parental literacy levels within families with a history of dyslexia. Journal of Child Psychology and Psychiatry, 53(1), 28-36.
https://doi.org/10.1111/j.1469-7610.2011.02418.x
van Bergen, E., de Jong, P. F., Regtvoort, A., Oort, F., van Otterloo, S., & van der Leij, A. (2011). Dutch children at family risk of dyslexia: Precursors, reading development, and parental effects. Dyslexia, 17(1), 2-18.
https://doi.org/10.1002/dys.423
van Bergen, E., van der Leij, A., & de Jong, P. F. (2014b). The intergenerational multiple deficit model and the case of dyslexia. Frontiers in human neuroscience, 8, 346.
https://doi.org/10.3389/fnhum.2014.00346
van Bergen, E., van Zuijen, T., Bishop, D., & de Jong, P. F. (2016). Why Are Home Literacy Environment and Children's Reading Skills Associated? What Parental Skills Reveal. Reading Research Quarterly, 52(2), 147-160.
https://doi.org/10.1002/rrq.160
Vellutino, F. R., Fletcher, J. M., Snowling, M. J., & Scanlon, D. M. (2004). Specific reading disability (dyslexia): what have we learned in the past four decades? Journal of Child Psychology and Psychiatry, 45(1), 2-40.
https://doi.org/10.1046/j.0021-9630.2003.00305.x
Wagner, R. K., & Torgesen, J. K. (1987). The nature of phonological processing and its causal role in the acquisition of reading skills. Psychological Bulletin, 101(2), 192-212.
https://doi.org/10.1037/0033-2909.101.2.192
Wechsler, D. (1991). WISC-III: Wechsler Intelligence Scale for Children : Manual. San Antonio, TX: Psychological Corporation.
Weigel, D. J., Martin, S. S., & Bennett, K. K. (2006). Contributions of the home literacy environment to preschool-aged children's emerging literacy and language skills. Early Child Development and Care, 176(3-4), 357-378.
https://doi.org/10.1080/03004430500063747
Whitehurst, G. J., & Lonigan, C. J. (1998). Child development and emergent literacy. Child Development, 69(3), 848-872.
https://doi.org/10.1111/j.1467-8624.1998.00848.x
Wolff, P. H., & Melngailis, I. (1994). Family patterns of developmental dyslexia: clinical findings. American Journal of Medical Genetics Part A, 54(2), 122-131.
