Hostname: page-component-586b7cd67f-t7fkt Total loading time: 0 Render date: 2024-11-28T16:17:49.123Z Has data issue: false hasContentIssue false
  • English
  • Français

Ed Zigler's developmental approach to intellectual disabilities: Past, present, and future contributions

Published online by Cambridge University Press:  06 May 2021

Robert M. Hodapp Open the ORCID record for Robert M. Hodapp [Opens in a new window]
Robert M. Hodapp*
Affiliation:
Department of Special Education, Peabody College, Vanderbilt University, Nashville, TN, USA
*
Author for correspondence: Robert M. Hodapp, PhD, Peabody College, Vanderbilt University, OMC Building Room 406-D, Peabody Box 228, Nashville, TN 37203, USA; E-mail: [email protected]
Get access Rights & Permissions [Opens in a new window]

Abstract

Comprising two parts, Ed Zigler's developmental approach has greatly influenced how one conceptualizes children with intellectual disabilities (ID). In part one, Zigler championed a “two-group approach” concerning the cause of children's ID. He distinguished persons with a clear, organic cause of their ID from those displaying no clear cause. Members of this “organic” group often displayed IQs below 50 and co-occurring physical–medical conditions. The second, “cultural–familial” group, mostly showed IQs of 50–70, did not possess co-occurring physical or health problems, and often came from families of lower IQs and lower socioeconomic status. While the presence of these two groups has been supported, recent advances have also further differentiated the organic group, mostly in relation to behavioral phenotypes of persons with several genetic etiologies. In part two, Zigler championed the child with ID as a “whole person.” Originally focused on the child's reactions to social deprivation and failure, recent studies directly examine parent–child, within-family, and wider system interactions throughout the life span. For decades a force within the ID field, Zigler's developmental approach to children with ID continues to influence researchers, interventionists, and policymakers.

Keywords

behavioral phenotypecultural–familial IDdevelopmental approach to intellectual disabilitiesDown syndromepersonality–motivational factorstwo-group approachWilliams syndrome
Type
Special Issue Article
Information
Development and Psychopathology , Volume 33 , Special Issue 2: Honoring the Legacy of Ed Zigler's Lifetime Contributions to Science, Society, and Child Wellbeing , May 2021 , pp. 453 - 465
Check for updates
Copyright
Copyright © The Author(s), 2021. Published by Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Abbeduto, L., Arias-Trejop, N., Thurman, A. J., Ramos-Sanchez, J., & del Hoyo Soriano, L. (in press). Language development in Down syndrome. In Burack, J. A., Edgin, J. & Abbeduto, L. (Eds.), Oxford handbook of Down syndrome and development. Oxford: Oxford University Press.Google Scholar
Alexander, K., Huganir, L. S., & Zigler, E. (1985). Effects of different living settings on mentally retarded individuals. American Journal of Mental Deficiency, 90, 9–17.Google ScholarPubMed
Bell, R Q. (1968). A reinterpretation of the direction of effects in studies of socialization. Psychological Review, 75, 81–95.CrossRefGoogle ScholarPubMed
Bennett, S. J., Holmes, J., & Buckley, S. (2013). Computerized memory training leads to sustained improvement in visuospatial short-term memory skills in children with Down-syndrome. American Journal on Intellectual and Developmental Disabilities, 118, 179–192. doi:10.1352/1944-7558-118.3.179CrossRefGoogle ScholarPubMed
Benyamin, B., Pourcain, B., Davis, O. S., Davies, G., Hansell, N. K., Brion, M. J., … Haworth, C. M. A. (2014). Childhood intelligence is heritable, highly polygenic, and associated with FNBP1L. Molecular Psychiatry, 19, 253–258.CrossRefGoogle ScholarPubMed
Bezzina, L. A., Rice, L. J., Howlin, P., Tonge, B. J., & Einfeld, S. L. (2017). Syndrome specific modules to enhance the Stepping Stones Triple P public health intervention. Journal of Intellectual Disability Research, 61, 836–842.CrossRefGoogle ScholarPubMed
Bishop, D. V. M. (2010). Which neurodevelopmental conditions get researched and why? PLoS ONE, 5, 1–11. e15112. doi:10.1371/journal.pone.0015112CrossRefGoogle Scholar
Blatt, B., & Kaplan, F. (1974). Christmas in purgatory: A photographic essay on mental retardation. Syracuse, NY: Human Policy Press.Google Scholar
Braddock, D., Emerson, E., Felce, D., & Stancliffe, R. J. (2001). Living circumstances of children with mental retardation or developmental disabilities in the United State, Canada, England, and Wales. Mental Retardation and Developmental Disabilities Research Reviews, 7, 115–121. doi:10.1002/mrdd.1016CrossRefGoogle ScholarPubMed
Broman, S., Nichols, P. L., Shaughnessy, P., & Kennedy, W. (1987). Retardation in young children: A developmental study of cognitive deficit. Hillsdale, NJ: Erlbaum.Google Scholar
Bronfenbrenner, U. (1979). The ecology of human development. Cambridge, MA: Harvard University Press.Google Scholar
Bunton, K., & Leddy, M. (2011). An evaluation of articulatory working space area in vowel production of adults with Down syndrome. Clinical Linguistics & Phonetics, 25, 321–334. doi:10.3109/02699206.2010.535647CrossRefGoogle ScholarPubMed
Burack, J. A. (1990). Differentiating mental retardation: The two-group approach and beyond. In Hodapp, R. M., Burack, J. A. & Zigler, E. (Eds.), Issues in the developmental approach to mental retardation (pp. 27–48). New York, NY: Cambridge University Press.CrossRefGoogle Scholar
Burack, J. A., Hodapp, R. M., Iarocci, G., & Zigler, E. (Eds.). (2011). The Oxford handbook of intellectual disability and development. Oxford: Oxford University Press.CrossRefGoogle Scholar
Burack, J. A., Hodapp, R. M., & Zigler, E. (1988). Issues in the classification of mental retardation: Differentiating among organic etiologies. Journal of Child Psychology and Psychiatry, 29, 765–779.CrossRefGoogle ScholarPubMed
Burack, J. A., Hodapp, R. M., & Zigler, E. (Eds.) (1998). Handbook of mental retardation and development. New York, NY: Cambridge University Press.Google Scholar
Burack, J. A., & Luthar, S. S. (2019). In memoriam: Edward Zigler (1930–2019). American Psychologist, 75, 410–411.CrossRefGoogle Scholar
Burack, J. A., Russo, N., Green, C. G., Landry, O., & Iarocci, G. (2016). Developments in the developmental approach to intellectual disability. In Cicchetti, D. (Ed.), Developmental psychopathology: Maladaptation and psychopathology (3rd ed.) (Vol. 3, pp. 1–67). Hoboken, NJ: Wiley.Google Scholar
Burke, M. M. (2010). Examining family involvement in regular and special education: Lessons to be learned for both sides. International Review of Research in Developmental Disabilities, 43, 187–218.CrossRefGoogle Scholar
Burke, M. M. (Ed.) (2018). Family-service connections throughout the lifespan. International Review of Research in Developmental Disabilities, 54, 1–250.Google Scholar
Burke, M. M., & Hodapp, R. M. (2014). Relating stress of mothers of children with developmental disabilities to educational services and partnerships. Intellectual and Developmental Disabilities, 52, 13–23.CrossRefGoogle ScholarPubMed
Burke, M. M., Patton, K. A., & Lee, C. (2016). Parent advocacy across the lifespan. International Review of Research in Developmental Disabilities, 51, 193–231.CrossRefGoogle Scholar
Bybee, J. A., & Zigler, E. (1992). Is outerdirectedness employed in a harmful or beneficial manner by students with and without mental retardation? American Journal on Mental Retardation, 96, 512–521.Google ScholarPubMed
Chicoine, B., McGuire, D., Hebein, S., & Gilly, D. (1995). Use of the community-oriented primary care model for a special-needs population: A clinic for adults with Down syndrome. American Journal of Public Health, 85, 869–870.Google ScholarPubMed
Cicchetti, D., & Beeghly, M. (Eds.) (1990). Children with Down Syndrome: A developmental perspective. Cambridge: Cambridge University Press.CrossRefGoogle Scholar
Cicchetti, D., & Ganiban, J. (1990). The organization and coherence of developmental processes in infants and children with Down syndrome. In Hodapp, R. M., Burack, J. A. & Zigler, E. (Eds.), Issues in the developmental approach to mental retardation (pp. 169–225). Cambridge: Cambridge University Press.CrossRefGoogle Scholar
Cicchetti, D., & Pogge-Hesse, P. (1982). Possible contributions of the study of organically retarded persons to developmental theory. In Zigler, E. & Balla, D. (Eds.), Mental retardation: The developmental-difference controversy (pp. 277–318). Hillsdale, NJ: Erlbaum.Google Scholar
Dingman, H. F., & Tarjan, G. (1960). Mental retardation and the normal distribution curve. American Journal of Mental Deficiency, 64, 991–994.Google Scholar
D'Souza, D., D'Souza, H., Jones, E. J. H., & Karmiloff-Smith, A. (2020). Attentional abilities constrain language development: A cross-syndrome infant/toddler study. Developmental Science, 64: e12961. doi:10.1111/desc.12961Google Scholar
Dykens, E. M. (1995). Measuring behavioral phenotypes: Provocations from the “new genetics”. American Journal on Mental Retardation, 99, 522–532.Google ScholarPubMed
Dykens, E. M. (2003). Anxiety, fears, and phobias in persons with Williams syndrome. Developmental Neuropsychology, 23, 291–316.CrossRefGoogle ScholarPubMed
Dykens, E. M. (2013). Aging in rare intellectual disability syndromes. Developmental Disability Research Reviews, 18, 75–83.CrossRefGoogle ScholarPubMed
Dykens, E. M. (2021). Behavioral phenotypes and genomic testing: Scientific and societal implications. In Glidden, L. M., Abbeduto, L., McIntyre, L.L., & Tasse, M.J. (Eds.), APA Handbook of Intellectual and Developmental Disabilities. Washington, DC: American Psychiatric Association.Google Scholar
Dykens, E. M., & Hodapp, R. M. (1997). Treatment issues in genetic mental retardation syndromes. Professional Psychology: Research and Practice, 28, 263–270.CrossRefGoogle Scholar
Dykens, E. M., Hodapp, R. M., & Finucane, B. (2000). Genetics and mental retardation syndromes: A new look at behavior and interventions. Baltimore, MD: Brookes.Google Scholar
Dykens, E. M., Hodapp, R. M., & Leckman, J. F. (1994). Behavior and development in fragile X syndrome. In Kazdin, A. E. (Ed.), Sage Series on Developmental Clinical Psychology and Psychiatry (Vol. 28, pp. 1–130). Newbury Park, CA: Sage Publications.Google Scholar
Dykens, E. M., Leckman, J. F., & Cassidy, S. B. (1996). Obsessions and compulsions in Prader–Willi syndrome. Journal of Child Psychology and Psychiatry, 37, 995–1002.CrossRefGoogle ScholarPubMed
Edgerton, R. B. (1967). The cloak of competence: Stigma in the lives of the mentally retarded. Berkeley, CA: University of California Press.Google Scholar
Einfeld, S. L., Tonge, B. J., & Florio, T. (1997). Behavioral and emotional disturbance in individuals with Williams syndrome. American Journal on Mental Retardation, 102, 45–53.2.0.CO;2>CrossRefGoogle ScholarPubMed
Esbensen, A. J., Seltzer, M. M., & Krauss, M. W. (2012). Life course perspectives in intellectual disability research: The case of family caregiving. In Burack, J. A., Hodapp, R. M., Iarocci, G. & Zigler, E. (Eds.), The Oxford handbook of intellectual disability and development (pp. 380–391). Oxford: Oxford University Press.Google Scholar
Eyman, R. K., & Miller, C. A. (1978). A demographic overview of severe and profound mental retardation. In Meyers, C. E. (Ed.), Quality of life in severely and profoundly mentally retarded people: Research foundations for improvement. Monographs of the American Association on Mental Deficiency (vol. 3, pp. ix–xii). Washington, DC: AAMD.Google Scholar
Fidler, D. J. (Ed.) (2011). Early development in neurogenetic disorders. International Review of Research in Developmental Disorders, 40, 1–302.Google Scholar
Fidler, D. J. (2012). Child eliciting effects in families of children with intellectual disabilities: Proximal and distal perspectives. In Burack, J. A., Hodapp, R. M., Iarocci, G. & Zigler, E. (Eds.), The Oxford handbook of intellectual disability and development (pp. 366–379). Oxford: Oxford University Press.Google Scholar
Fidler, D. J., Most, D. E., Booth-LaForce, C., & Kelly, J. F. (2008). Emerging social strengths in young children with Down syndrome. Infants & Young Children, 21, 207–220.CrossRefGoogle Scholar
Fidler, D. J., & Nadel, L. (2007). Education and children with Down syndrome: Neuroscience, development, and intervention. Mental Retardation and Developmental Disabilities Research Reviews, 13, 262–271.CrossRefGoogle Scholar
Fidler, D. J., Schworer, E., Prince, M. A., Will, E. A., Needham, A. W., & Daunhauer, L. A. (2019). Exploratory behavior and developmental skill acquisition in infants with Down syndrome. Infant Behavior and Development, 54, 140–150.CrossRefGoogle ScholarPubMed
Fisher, M. H., Moskowitz, A. L., & Hodapp, R. M. (2013). Differences in social vulnerability among individuals with autism spectrum disorder, Williams syndrome, and Down syndrome. Research in Autism Spectrum Disorders, 7, 931–937. doi:10.1016/j.rasd.2013.04.009CrossRefGoogle ScholarPubMed
Flynt, J., & Yule, W. (1994). Behavioural phenotypes. In Rutter, M., Taylor, E. & Hersov, L. (Eds.), Child and adolescent psychiatry: Modern approaches (3rd ed, pp. 666–687). London: Blackwell Scientific.Google Scholar
Gibson, D. (1978). Down's syndrome: The psychology of mongolism. London: Cambridge University Press.Google Scholar
Glidden, L. M. (2012). Family well-being and children with intellectual disability. In Burack, J. A., Hodapp, R. M., Iarocci, G. & Zigler, E. (Eds.), The Oxford handbook of intellectual disability and development (pp. 303–317). Oxford: Oxford University Press.Google Scholar
Glidden, L. M., Floyd, F. J., Hastings, R. P., & Mailick, M. (in press). Family impact and adjustment: Parents. In Glidden, L. M., Abbeduto, L., McIntyre, L.L., & Tasse, M.J. (Eds.), APA Handbook of Intellectual and Developmental Disabilities. Washington, DC: American Psychiatric Association.Google Scholar
Goldman, S. E. (2020). Special education advocacy for families of students with intellectual and developmental disabilities: Current trends and future directions. International Review of Research in Developmental Disabilities, 58, 1–50.CrossRefGoogle Scholar
Goscicki, B. L., Josol, C. K., Fisher, M. H., Dykens, E. M., & Hodapp, R. M. (in press). Decision making and etiology: Considerations and implications. In Khemka, I., & Hickson, L. (Eds.), Decision making by individuals with IDD: Research and practice. Positive Psychology and Disabilities Series. New York: NY: Springer.Google Scholar
Gothelf, D., Farber, N., Raveh, E., Apter, A., & Attias, J. (2006). Hyperacusis in William syndrome: Characteristics and associated neuroaudiologic abnormalities. Neurology, 66, 390–395.CrossRefGoogle ScholarPubMed
Gottesman, I. I. (1963). Genetic aspects of intelligent behavior. In Ellis, N. (Ed.), Handbook of mental deficiency (pp. 253–296). New York, NY: McGraw-Hill.Google Scholar
Granat, K., & Granat, S. (1978). Adjustment of intellectually below-average men not identified as mentally retarded. Scandinavian Journal of Psychology, 19, 41–51.CrossRefGoogle Scholar
Harris, S., Kasari, C., & Sigman, M. D. (1996). Joint attention and language gains in children with Down syndrome. American Journal on Mental Retardation, 100, 608–619.Google ScholarPubMed
Harter, S., & Zigler, E. (1968). Effectiveness of adult and peer reinforcement on the performance of institutionalized and non-institutionalized retardates. Journal of Abnormal Psychology, 73, 144–149.CrossRefGoogle Scholar
Hauser-Cram, P., Howell-Moneta, A. N., & Young, J. M. (2012). Dyadic interaction between mothers and children with Down syndrome or Williams syndrome: Empirical evidence and emerging agendas. In Burack, J. A., Hodapp, R. M., Iarocci, G. & Zigler, E. (Eds.), The Oxford handbook of intellectual disability and development (pp. 318–333). Oxford: Oxford University Press.Google Scholar
Heller, T. (2019). Bridging aging and intellectual/developmental disabilities in research, policy, and practice. Journal of Policy and Practice in Intellectual Disabilities, 16, 53–57. doi:10.1111/jppi.12263CrossRefGoogle Scholar
Hepburn, S. L., Fidler, D. J., Hahn, L., & Philofsky, A. (2011). Social-perceptual and social-cognitive skills in young children with Williams syndrome: Evidence for discontinuity. International Review of Research in Developmental Disabilities, 40, 181–210.CrossRefGoogle Scholar
Hodapp, R. M. (1997). Direct and indirect behavioral effects of different genetic disorders of mental retardation. American Journal on Mental Retardation, 102, 67–79.2.0.CO;2>CrossRefGoogle ScholarPubMed
Hodapp, R. M., Burack, J. A., & Zigler, E. (Eds.) (1990). Issues in the developmental approach to mental retardation. Cambridge: Cambridge University Press.CrossRefGoogle Scholar
Hodapp, R. M., Casale, E. G., & Sanderson, K. A. (2019). Parenting children with intellectual disabilities. In Bornstein, M. (Ed.), Handbook of parenting. Volume 1: How children influence parents (3rd ed., pp. 565–596). Hillsdale, NJ: Erlbaum.CrossRefGoogle Scholar
Hodapp, R. M., & Dykens, E. M. (1994). Mental retardation's two cultures of behavioral research. American Journal on Mental Retardation, 98, 675–687.Google ScholarPubMed
Hodapp, R. M., & Dykens, E. M. (2001). Strengthening behavioral research on genetic mental retardation syndromes. American Journal on Mental Retardation, 106, 4–15.2.0.CO;2>CrossRefGoogle ScholarPubMed
Hodapp, R. M., & Dykens, E. M. (2012). Genetic disorders of intellectual disability: Expanding our concepts of phenotypes and of family outcomes. Journal of Genetic Counseling, 21, 761–769. doi:10.1007/s10897-012-9536-4CrossRefGoogle ScholarPubMed
Hodapp, R. M., & Fidler, D. J. (1999). Special education and genetics: Connections for the 21st century. Journal of Special Education, 33, 130–137.CrossRefGoogle Scholar
Hodapp, R. M., & Fidler, D. J. (in press). Down syndrome. In Glidden, L. M., Abbeduto, L., McIntyre, L.L., & Tasse, M.J. (Eds.), APA Handbook of Intellectual and Developmental Disabilities. Washington, DC: American Psychological Association.Google Scholar
Hodapp, R. M., & Fisher, M. (2017). Using genetic etiology to intervene with students with intellectual disabilities. In Bouregy, S., Grigorenko, E., Latham, S. & Tan, M. (Eds.), Genetics, ethics and education (pp. 183–201). Cambridge: Cambridge University Press.CrossRefGoogle Scholar
Hodapp, R. M., Glidden, L. M., & Kaiser, A. P. (2005). Siblings of persons with disabilities: Toward a research agenda. Mental Retardation, 43, 334–338.Google ScholarPubMed
Hodapp, R. M., Rosemergy, J., Garcia, B. L., Meskis, S. A., Hart, M., & McMillan, E. (2018). Information and referral services in IDD: Toward integrated and comprehensive services? International Review of Research in Developmental Disabilities, 54, 211–250.CrossRefGoogle Scholar
Iarocci, G., & Petril, S. (2012). Behavioral genetics, genomics, intelligence, and mental retardation. In Burack, J. A., Hodapp, R. M., Iarocci, G. & Zigler, E. (Eds.), The Oxford handbook of intellectual disability and development (pp. 13–29). Oxford: Oxford University Press.Google Scholar
Karam, S. M., Riegel, M., Segal, S. L., Félix, T. M., Barros, A. J. D., Santos, I. S., … Black, M. (2015). Genetic causes of intellectual disability in a birth cohort: A population-based study. American Journal of Medical Genetics Part A, 167, 1204–1214. doi:10.1002/ajmg.a.37011CrossRefGoogle Scholar
Kasari, C., & Freeman, S. F. N. (2001). Task-related social behavior in children with Down syndrome. American Journal on Mental Retardation, 106, 253–264.2.0.CO;2>CrossRefGoogle ScholarPubMed
Krahn, G. L., Hammond, L., & Turner, A. (2006). A cascade of disparities: Health and healthcare access for people with intellectual disabilities. Mental Retardation and Developmental Disabilities Research Reviews, 12, 70–82.CrossRefGoogle ScholarPubMed
Kreicher, K. L., Weir, F. W., Nguyen, S. A., & Meyer, T. A. (2018). Characteristics and progression of hearing loss in children with Down syndrome. The Journal of Pediatrics, 193, 27–33e2. doi:10.1016/j.jpeds.2017.09.053CrossRefGoogle ScholarPubMed
Kreitler, S., & Zigler, E. (1990). Motivational determinants of children's probability learning. The Journal of Genetic Psychology: Research and Theory on Human Development, 151, 301–316.CrossRefGoogle Scholar
Lemons, C. J., King, S. A., Davidson, K. A., Puranik, C. S., Al Otaiba, S., & Fidler, D. J. (2018). Personalized reading intervention for children with Down syndrome. Journal of School Psychology, 66, 67–84.CrossRefGoogle ScholarPubMed
Lemons, C. J., King, S. A., Davidson, K. A., Puranik, C. S., Fulmer, D., Mrachko, A. A., … Fidler, D. J. (2015). Adapting phonological awareness interventions for children with Down syndrome based on the behavioral phenotype: A promising approach? Intellectual and Developmental Disabilities, 53, 271–288. doi:10.1352/1934-9556-53.4.271CrossRefGoogle ScholarPubMed
Lewis, E. O. (1933). Types of mental deficiency and their social significance. Journal of Mental Science, 79, 298–304.CrossRefGoogle Scholar
Lin, J. D., Lin, L. P., Hsu, S. W., Chen, W. X., Lin, F. G., Wu, J. L., & Chu, C. (2015). Are early onset aging conditions correlated to daily activity functions in youth and adults with Down syndrome? Research in Developmental Disabilities, 36, 532–536. doi:10.1016/j.ridd.2014.10.051CrossRefGoogle Scholar
MacMillan, D. L., Gresham, F. M., & Bocian, K. M. (1998). Discrepancy between definitions of learning disabilities and school practices: An empirical investigation. Journal of Learning Disabilities, 31, 314–326. doi:10.1177/002221949803100401CrossRefGoogle Scholar
Opitz, J. M. (1985). Editorial comment: The developmental field concept. American Journal of Medical Genetics, 21, 1–11.CrossRefGoogle Scholar
Owens, P. L., Kerker, B. D., Zigler, E., & Horwitz, S. M. (2006). Vision and oral health needs of individuals with intellectual disability. Mental Retardation and Developmental Disabilities Research Reviews, 12, 28–40.CrossRefGoogle ScholarPubMed
Penrose, L. S. (1938). A clinical and genetic study of 1280 cases of mental defect. London: HM Stationery Office.Google Scholar
Pitcairn, T. K., & Wishart, J. G. (1994). Reactions of young children with Down's syndrome to an impossible task. British Journal of Developmental Psychology, 12, 485–489.CrossRefGoogle Scholar
Plomin, R. B., & Deary, I. J. (2015). Genetics and intelligence differences: Five specific findings. Molecular Psychiatry, 20, 98–108.CrossRefGoogle Scholar
Provence, S., & Lipton, R. C. (1962). Infants in institutions. Oxford: International University Press.Google Scholar
Pulina, F., Carretti, B., Lanfranchi, S., & Mammarella, I. C. (2015). Improving spatial-simultaneous working memory in Down syndrome: Effect of a training program led by parents instead of an expert. Frontiers in Psychology, 6, 1265. doi:10.3389/fpsyg.2015.01265CrossRefGoogle ScholarPubMed
Reichenberg, A., Cederlof, M., McMillan, A., Trzaskowski, M., Kapara, O., Fruchter, E., … Lichtenstein, P. (2016). Discontinuity in the genetic and environmental causes of the intellectual disability spectrum. Proceedings of the National Academy of Sciences, 113, 1098–1103.CrossRefGoogle ScholarPubMed
Sameroff, A. J. (1990). Neo-environmental perspectives on developmental theory. In Hodapp, R. M., Burack, J. A. & Zigler, E. (Eds.), Issues in the developmental approach to mental retardation (pp. 93–113). Cambridge: Cambridge University Press.CrossRefGoogle Scholar
Sameroff, A, & Chandler, M. (1975). Reproductive risk and the continuum of caretaker casualty. In Horowitz, F.D., Hetherington, M., Scarr-Salapatek, S., & Siegel, G. (Eds.), Review of child development research (Vol. 4, pp. 187–244). Chicago: University of Chicago Press.Google Scholar
Smith, S. E., McCann, H. P., Dykens, E. M., & Hodapp, R. M. (2020). The disability training needs of healthcare professionals: A scoping review and new initiatives. International Review of Research in Developmental Disabilities, 58, 219–264.CrossRefGoogle Scholar
Solomon, M., Pistrang, N., & Barker, C. (2001). The benefits of mutual support groups for parents of children with disabilities. American Journal of Community Psychology, 29, 113–132.CrossRefGoogle ScholarPubMed
Stevenson, H. W., & Zigler, E. (1957). Discrimination learning and rigidity in normal and feebleminded children. Journal of Personality, 25, 699–711.CrossRefGoogle Scholar
Stromme, P., & Hagberg, G. (2000). Aetiology in severe and mild mental retardation: A population-based study of Norwegian children. Developmental Medicine & Child Neurology, 42, 76–86.CrossRefGoogle ScholarPubMed
Switzky, H. N. (Ed.) (2004). Mental retardation: Personality and motivational systems in mental retardation. International Review of Research in Mental Retardation, 28, 1–337.Google Scholar
Thurman, A. J., & Fisher, M. H. (2015). The Williams syndrome social phenotype: Disentangling the contributions of social interest and social difficulties. International Review of Research in Developmental Disabilities, 49, 191–227. doi:10.1016/bs.irrdd.2015.06.002CrossRefGoogle Scholar
Tonge, B. J., & Einfeld, S. L. (2003). Psychopathology and intellectual disability: The Australian child to adult longitudinal study. International Review of Research in Mental Retardation, 26, 61–91.CrossRefGoogle Scholar
Tyrer, F., Smith, L. K., McGrother, C. W., & Taub, N. A. (2007). The impact of physical, intellectual, and social determinants on survival in adults with intellectual disability: A population-based register study. Journal of Applied Research in Intellectual Disabilities, 20, 360–367.CrossRefGoogle Scholar
Udwin, O., Yule, W., & Martin, N. (1987). Cognitive abilities and behavioral characteristics of children with idiopathic infantile hypercalcaemia. Journal of Child Psychology and Psychiatry, 28, 297–309.CrossRefGoogle ScholarPubMed
Ulrich, D. A., Lloyd, M. C., Tiernan, C. W., Looper, J. E., & Angulo-Barroso, R. M. (2008). Effects of intensity of treadmill training on developmental outcomes and stepping in infants with Down syndrome: A randomized trial. Physical Therapy, 88, 114–122. doi:10.2522/ptj.20070139CrossRefGoogle ScholarPubMed
Uzgiris, I. C., & Hunt, J. M. (1975). Assessment in infancy: Ordinal scales of psychological development. Urbana, IL: University of Illinois Press.Google Scholar
Vissers, L. E. L. M., Gilissen, C., & Veltman, J. A. (2016). Genetic studies in intellectual disability and related disorders. Nature Reviews Genetics, 17, 9–18. doi:10.1038/nrg3999CrossRefGoogle ScholarPubMed
Weaver, S. J., Balla, D., & Zigler, E. (1971). Social approach and avoidance tendencies of institutionalized retarded and noninstitutionalized retarded and normal children. Journal of Experimental Research in Personality, 5, 98–110.Google Scholar
Weiss, B., Weisz, J. R., & Bromfield, R. (1986). Performance of retarded and nonretarded persons on information-processing tasks: Further tests of the similar-structure hypothesis. Psychological Bulletin, 100, 157–175.CrossRefGoogle ScholarPubMed
Weisz, J. R., & Yeates, O. W. (1981). Cognitive development in retarded and nonretarded persons: Piagetian tests of the similar structure hypothesis. Psychological Bulletin, 90, 153–178.CrossRefGoogle ScholarPubMed
Weisz, J. R., Yeates, O. W., & Zigler, E. (1982). Piagetian evidence and the developmental-difference controversy. In Zigler, E. & Balla, D. (Eds.), Mental retardation: The developmental-difference controversy (pp. 213–276). Hillsdale, NJ: Erlbaum.Google Scholar
Weisz, J. R., & Zigler, E. (1979). Cognitive development in retarded and nonretarded persons: Piagetian tests of the similar sequence hypothesis. Psychological Bulletin, 86, 831–851.CrossRefGoogle ScholarPubMed
Yoder, P. J., & Warren, S. F. (2002). Effects of prelinguistic milieu teaching and parent responsivity education on dyads involving children with intellectual disabilities. Journal of Speech, Language, and Hearing Research, 45, 1158–1174. doi:10.1044/1092-4388(2002/094)CrossRefGoogle ScholarPubMed
Zigler, E. (1961). Social deprivation and rigidity in the performance of feebleminded children. Journal of Abnormal and Social Psychology, 62, 413–421.CrossRefGoogle ScholarPubMed
Zigler, E. (1962). Social deprivation in familial and organic retardates. Psychological Reports, 10, 370.CrossRefGoogle Scholar
Zigler, E. (1967). Familial mental retardation: A continuing dilemma. Science, 155, 292–298.CrossRefGoogle ScholarPubMed
Zigler, E. (1969). Developmental versus difference theories of retardation and the problem of motivation. American Journal of Mental Deficiency, 73, 536–556.Google ScholarPubMed
Zigler, E. (1970). The environmental mystique: Training the intellect versus development of the child. Childhood Education, 46, 402–412.CrossRefGoogle Scholar
Zigler, E. (1971). The retarded child as a whole person. In Adams, H. E., & Boardman, W. K. (Eds.), Advances in experimental clinical psychology (pp. 47–122). New York, NY: Pergamon Press.CrossRefGoogle Scholar
Zigler, E., & Balla, D. (Eds.) (1982). Mental retardation: The developmental-difference controversy. Hillsdale, NJ: Erlbaum.Google Scholar
Zigler, E., & Bennett-Gates, D. (Eds.) (1999). Personality development in individuals with mental retardation. New York, NY: Cambridge University Press.Google Scholar
Zigler, E., Bennett-Gates, D., Hodapp, R. M., & Heinrich, C. C. (2002). Assessing personality traits of individuals with mental retardation. American Journal on Mental Retardation, 107, 181–193.2.0.CO;2>CrossRefGoogle ScholarPubMed
Zigler, E., Butterfield, E. C., & Goff, G. (1962). A measure of pre-institutional social deprivation for institutionalized retardates. American Journal of Mental Deficiency, 70, 873–880.Google Scholar
Zigler, E., & Hodapp, R. M. (1986). Understanding mental retardation. New York, NY: Cambridge University Press.Google Scholar
Zigman, W. B. (2013). Atypical aging in Down syndrome. Developmental Disabilities Research Reviews, 18, 51–67.CrossRefGoogle ScholarPubMed