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Family Socioeconomic Status and Child Executive Functions: The Roles of Language, Home Environment, and Single Parenthood

Published online by Cambridge University Press:  15 November 2010

Khaled Sarsour*
Affiliation:
Epidemiology and Health Services Research, Global Health Outcomes, Eli Lilly and Company, Indianapolis, Indiana
Margaret Sheridan
Affiliation:
Health and Society Scholars Program, Harvard School of Public Health, Boston, Massachusetts
Douglas Jutte
Affiliation:
School of Public Health, University of California, Berkeley, California
Amani Nuru-Jeter
Affiliation:
School of Public Health, University of California, Berkeley, California
Stephen Hinshaw
Affiliation:
Department of Psychology, University of California, Berkeley, California
W. Thomas Boyce
Affiliation:
College for Interdisciplinary Studies and Faculty of Medicine, University of British Columbia, Vancouver, Canada
*
Correspondence and reprint requests to: Khaled Sarsour, Lilly Corporate Center, DC 1833, Indianapolis, IN 46285. E-mail: [email protected]

Abstract

The association between family socioeconomic status (SES) and child executive functions is well-documented. However, few studies have examined the role of potential mediators and moderators. We studied the independent and interactive associations between family SES and single parenthood to predict child executive functions of inhibitory control, cognitive flexibility, and working memory and examined child expressive language abilities and family home environment as potential mediators of these associations. Sixty families from diverse SES backgrounds with a school-age target child (mean [SD] age = 9.9 [0.96] years) were evaluated. Child executive functioning was measured using a brief battery. The quality of the home environment was evaluated using the Home Observation for the Measurement of the Environment inventory. Family SES predicted the three child executive functions under study. Single parent and family SES were interactively associated with children’s inhibitory control and cognitive flexibility; such that children from low SES families who were living with one parent performed less well on executive function tests than children from similarly low SES who were living with two parents. Parental responsivity, enrichment activities and family companionship mediated the association between family SES and child inhibitory control and working memory. This study demonstrates that family SES inequalities are associated with inequalities in home environments and with inequalities in child executive functions. The impact of these disparities as they unfold in the lives of typically developing children merits further investigation and understanding. (JINS, 2011, 17, 000–000)

Type
Research Articles
Copyright
Copyright © The International Neuropsychological Society 2010

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References

Allison, P.D., Furstenberg, F.F. (1989). How marital dissolution affects children - variations by age and sex. Developmental Psychology, 25(4), 540549.CrossRefGoogle Scholar
Alvarez, J.A., Emory, E. (2006). Executive function and the frontal lobes: A meta-analytic review. Neuropsychology Review, 16(1), 1742.CrossRefGoogle ScholarPubMed
Andersen, S.L. (2003). Trajectories of brain development: Point of vulnerability or window of opportunity? Neuroscience and Biobehavioral Reviews, 27(1–2), 318.CrossRefGoogle ScholarPubMed
Anderson, V.A., Anderson, P., Northam, E., Jacobs, R., Catroppa, C. (2001). Development of executive functions through late childhood and adolescence in an Australian sample. Developmental Neuropsychology, 20(1), 385406.CrossRefGoogle Scholar
Ardila, A., Rosselli, M., Matute, E., Guajardo, S. (2005). The influence of the parents’ educational level on the development of executive functions. Developmental Neuropsychology, 28(1), 539560.CrossRefGoogle ScholarPubMed
Baddeley, A. (1998). Working memory. Comptes rendus de l’Académie des sciences. Série III, Sciences de la vie, 321(2–3), 167173.Google ScholarPubMed
Barber, B.L., Eccles, J.S. (1992). Long-term influence of divorce and single parenting on adolescent family- and work-related values, behaviors, and aspirations. Psychology Bulletin, 111(1), 108126.CrossRefGoogle ScholarPubMed
Barkley, R.A. (2001). The executive functions and self-regulation: An evolutionary neuropsychological perspective. Neuropsychology Review, 11(1), 129.CrossRefGoogle ScholarPubMed
Baron, I.S. (2004). Neuropsychological evaluation of the child. Oxford and New York: Oxford University Press.Google Scholar
Baron, R.M., Kenny, D.A. (1986). The moderator-mediator variable distinction in social psychological research: Conceptual, strategic, and statistical considerations. Journal of Personality and Social Psychology, 51(6), 11731182.CrossRefGoogle ScholarPubMed
Baumeister, R.F., Vohs, K.D. (2004). Handbook of self-regulation: Research, theory, and applications. New York: Guilford Press.Google Scholar
Blair, C. (2002). School readiness. Integrating cognition and emotion in a neurobiological conceptualization of children’s functioning at school entry. The American Psychologist, 57(2), 111127.CrossRefGoogle Scholar
Blair, C., Granger, D., Peters Razza, R. (2005). Cortisol reactivity is positively related to executive function in preschool children attending head start. Child Development, 76(3), 554567.CrossRefGoogle ScholarPubMed
Bornstein, M.H., Bradley, R.H. (Eds.). (2003). Socioeconomic status, parenting, and child development. Mahwah, NJ: Lawrence Erlbaum Associates.Google Scholar
Boyce, W.T. (2004). Social stratification, health, and violence in the very young. Annals of the New York Academy of Sciences, 1036, 4768.CrossRefGoogle ScholarPubMed
Boyce, W.T., Essex, M.J., Woodward, H.R., Measelle, J.R., Ablow, J.C., Kupfer, D.J. (2002). The confluence of mental, physical, social, and academic difficulties in middle childhood. I: Exploring the “head waters” of early life morbidities. Journal of the American Academy of Child and Adolescent Psychiatry, 41(5), 580587.CrossRefGoogle ScholarPubMed
Bradley, R.H., Caldwell, B.M. (1977). Home observation for measurement of the environment: A validation study of screening efficiency. American Journal of Mental Deficiency, 81(5), 417420.Google ScholarPubMed
Bradley, R.H., Corwyn, R.F. (2002). Socioeconomic status and child development. Annual Review of Psychology, 53, 371399.CrossRefGoogle ScholarPubMed
Bradley, R.H., Corwyn, R.F., Burchinal, M., McAdoo, H.P., Coll, C.G. (2001). The home environments of children in the United States. II: Relations with behavioral development through age thirteen. Child Development, 72(6), 18681886.CrossRefGoogle ScholarPubMed
Bradley, R.H., Corwyn, R.F., McAdoo, H.P., Coll, C.G. (2001). The home environments of children in the United States. I: Variations by age, ethnicity, and poverty status. Child Development, 72(6), 18441867.CrossRefGoogle ScholarPubMed
Brocki, K.C., Bohlin, G. (2004). Executive functions in children aged 6 to 13: A dimensional and developmental study. Developmental Neuropsychology, 26(2), 571593.CrossRefGoogle ScholarPubMed
Brooks-Gunn, J., Duncan, G.J. (1997). The effects of poverty on children. The Future of Children, 7(2), 5571.CrossRefGoogle ScholarPubMed
Brooks-Gunn, J., Klebanov, P.K., Duncan, G.J. (1996). Ethnic differences in children’s intelligence test scores: Role of economic deprivation, home environment, and maternal characteristics. Child Development, 67(2), 396408.CrossRefGoogle ScholarPubMed
Caldwell, B., Bradley, R.H. (2005). HOME inventory administration manual, standard edition (Training Manual). Little Rock: University of Arkansas.Google Scholar
Calkins, S.D., Fox, N.A. (2002). Self-regulatory processes in early personality development: A multilevel approach to the study of childhood social withdrawal and aggression. Developmental Psychopathology, 14(3), 477498.CrossRefGoogle Scholar
Case, R., Griffin, S., Kelly, W.M. (1999). Socioeconomic gradients in mathematical ability and their responsiveness to intervention during early childhood. In D.P. Keating, & C. Hertzman (Eds.), Developmental health and the wealth of nations: social, biological and educational dynamics (pp. 125–149). New York: The Guilford Press.Google Scholar
Chen, E., Matthews, K.A., Boyce, W.T. (2002). Socioeconomic differences in children’s health: How and why do these relationships change with age? Psychology Bulletin, 128(2), 295329.CrossRefGoogle ScholarPubMed
Cohen, J., Cohen, J. (2003). Applied multiple regression/correlation analysis for the behavioral sciences. Mahwah, NJ: Erlbaum Associates.Google Scholar
Currie, J. (2005). Health disparities and gaps in school readiness. The Future of Children, 15(1), 117138.CrossRefGoogle ScholarPubMed
Davidson, M.C., Amso, D., Anderson, L.C., Diamond, A. (2006). Development of cognitive control and executive functions from 4 to 13 years: Evidence from manipulations of memory, inhibition, and task switching. Neuropsychologia, 44(11), 20372078.CrossRefGoogle ScholarPubMed
Dearing, E., McCartney, K., Taylor, B.A. (2001). Change in family income-to-needs matters more for children with less. Child Development, 72(6), 17791793.CrossRefGoogle ScholarPubMed
Dethorne, L.S., Johnson, B.W., Loeb, J.W. (2005). A closer look at MLU: What does it really measure? Clinical Linguistics & Phonetics, 19(8), 635648.CrossRefGoogle Scholar
Diamond, A. (2002). Normal development of prefrontal cortex from birth to young adulthood: Cognitive functions, anatomy, and biochemistry. In D.T. Stuss & R.T. Knight (Eds.), Principles of frontal lobe function (pp. 466503). New York, NY: Oxford University Press.CrossRefGoogle Scholar
Diamond, A. (2006). The early development of executive functions. In E. Bialystok & F.I.M. Craik (Eds.), Lifespan cognition: Mechanisms of change (pp. 7095). New York, NY: Oxford University Press.CrossRefGoogle Scholar
Diamond, A. (2007). Consequences of variations in genes that affect dopamine in prefrontal cortex. Cerebral Cortex, 17(Suppl 1), i161i170.CrossRefGoogle ScholarPubMed
Diamond, A. (2009). The interplay of biology and the environment broadly defined. Developmental Psychology, 45(1), 18.CrossRefGoogle ScholarPubMed
Diamond, A., Barnett, W.S., Thomas, J., Munro, S. (2007). Preschool program improves cognitive control. Science, 318(5855), 13871388.CrossRefGoogle ScholarPubMed
Eaker, D.G., Walters, L.H. (2002). Adolescent satisfaction in family rituals and psychosocial development: A developmental systems theory perspective. Journal of Family Psychology, 16(4), 406414.CrossRefGoogle ScholarPubMed
East, L., Jackson, D., O’Brien, L. (2006). Father absence and adolescent development: A review of the literature. Journal Child Health Care, 10(4), 283295.CrossRefGoogle ScholarPubMed
Essex, M.J., Kraemer, H.C., Armstrong, J.M., Boyce, T., Goldsmith, H.H., Klein, M.H., Kupfer, D.J. (2006). Exploring risk factors for the emergence of children’s mental health problems. Archives of General Psychiatry, 63(11), 12461256.CrossRefGoogle ScholarPubMed
Evans, G.W. (2006). Child development and the physical environment. Annual Review of Psychology, 57, 423451.CrossRefGoogle ScholarPubMed
Evans, G.W., English, K. (2002). The environment of poverty: Multiple stressor exposure, psychophysiological stress, and socioemotional adjustment. Child Development, 73(4), 12381248.CrossRefGoogle ScholarPubMed
Evans, G.W., Gonnella, C., Marcynyszyn, L.A., Gentile, L., Salpekar, N. (2005). The role of chaos in poverty and children’s socioemotional adjustment. Psychological Science, 16(7), 560565.CrossRefGoogle ScholarPubMed
Evans, G.W., Schamberg, M.A. (2009). Childhood poverty, chronic stress, and adult working memory. Proceedings of the National Academy of Sciences of the United States of America, 106(16), 65456549.CrossRefGoogle ScholarPubMed
Farah, M.J., Shera, D.M., Savage, J.H., Betancourt, L., Giannetta, J.M., Brodsky, N.L., Hurt, H. (2006). Childhood poverty: Specific associations with neurocognitive development. Brain Research, 1110(1), 166174.CrossRefGoogle ScholarPubMed
Forgas, J.P., Baumeister, R.F., Tice, D.M. (2009). Psychology of self-regulation: Cognitive, affective, and motivational processes. New York: Routledge.Google Scholar
Francis, D.D., Champagne, F.A., Liu, D., Meaney, M.J. (1999). Maternal care, gene expression, and the development of individual differences in stress reactivity. Annals of the New York Academy of Sciences, 896, 6684.CrossRefGoogle ScholarPubMed
Fuster, J.M. (1997). The prefrontal cortex: Anatomy, physiology, and neuropsychology of the frontal lobe. Philadelphia: Lippincott-Raven.Google Scholar
Golden, C.J. (1978). Stroop Color and Word Test: A manual for clinical and experimental uses. Chicago: Stoelting Co.Google Scholar
Guralnik, J.M., Butterworth, S., Wadsworth, M.E., Kuh, D. (2006). Childhood socioeconomic status predicts physical functioning a half century later. The Journals of Gerontology. Series A, Biological Sciences and Medical Sciences, 61(7), 694701.CrossRefGoogle ScholarPubMed
Hackman, D.A., Farah, M.J. (2009). Socioeconomic status and the developing brain. Trends in Cognitive Sciences, 13(2), 6573.CrossRefGoogle ScholarPubMed
Hackman, D.A., Farah, M.J., Meaney, M.J. (2010). Socioeconomic status and the brain: Mechanistic insights from human and animal research. Nature Reviews. Neuroscience, 11(9), 651659.CrossRefGoogle ScholarPubMed
Harden, K.P., Turkheimer, E., Loehlin, J.C. (2006). Genotype by environment interaction in adolescents’ cognitive aptitude. Behavior Genetics, 37, 273283.CrossRefGoogle ScholarPubMed
Hart, T., Risley, T.R. (1995). Meaningful differences in the everyday experience of young American children. Baltimore, MD: Paul H. Brookes.Google Scholar
Hertzman, C., Boyce, T. (2010). How experience gets under the skin to create gradients in developmental health. Annual Review of Public Health, 31, 329347, 3p following 347.CrossRefGoogle ScholarPubMed
Hoff, E. (2003). The specificity of environmental influence: Socioeconomic status affects early vocabulary development via maternal speech. Child Development, 74(5), 13681378.CrossRefGoogle ScholarPubMed
Hollingshead, A. (1975). Four factor index of social status. New Haven, CN: Department of Sociology, Yale University.Google Scholar
Holmbeck, G.N. (1997). Toward terminological, conceptual, and statistical clarity in the study of mediators and moderators: Examples from the child-clinical and pediatric psychology literatures. Journal of Consulting and Clinical Psychology, 65(4), 599610.CrossRefGoogle Scholar
Kane, M.J., Engle, R.W. (2002). The role of prefrontal cortex in working-memory capacity, executive attention, and general fluid intelligence: An individual-differences perspective. Psychonomic Bulletin & Review, 9(4), 637671.CrossRefGoogle ScholarPubMed
Kaplan, G.A., Turrell, G., Lynch, J.W., Everson, S.A., Helkala, E.L., Salonen, J.T. (2001). Childhood socioeconomic position and cognitive function in adulthood. International Journal of Epidemiology, 30(2), 256263.CrossRefGoogle ScholarPubMed
Karoly, P. (1993). Mechanisms of self-regulation - A systems view. Annual Review of Psychology, 44, 2352.CrossRefGoogle Scholar
Kishiyama, M.M., Boyce, W.T., Jimenez, A.M., Perry, L.M., Knight, R.T. (2008). Socioeconomic disparities affect prefrontal function in children. Journal of Cognitive Neuroscience, 21(6), 11061115.CrossRefGoogle Scholar
Kortte, K.B., Horner, M.D., Windham, W.K. (2002). The trail making test, part B: Cognitive flexibility or ability to maintain set? Applied Neuropsychology, 9(2), 106109.CrossRefGoogle ScholarPubMed
Kraemer, H.C., Stice, E., Kazdin, A., Offord, D., Kupfer, D. (2001). How do risk factors work together? Mediators, moderators, and independent, overlapping, and proxy risk factors. American Journal of Psychiatry, 158(6), 848856.CrossRefGoogle ScholarPubMed
Kroenke, C. (2008). Socioeconomic status and health: Youth development and neomaterialist and psychosocial mechanisms. Social Science & Medicine, 66(1), 3142.CrossRefGoogle ScholarPubMed
Lamm, C., Zelazo, P.D., Lewis, M.D. (2006). Neural correlates of cognitive control in childhood and adolescence: Disentangling the contributions of age and executive function. Neuropsychologia, 44(11), 21392148.CrossRefGoogle ScholarPubMed
Link, B.G., Phelan, J. (1995). Social conditions as fundamental causes of disease. Journal of Health and Social Behavior, Spec No, 8094.CrossRefGoogle ScholarPubMed
Link, B.G., Phelan, J.C. (1996). Understanding sociodemographic differences in health--the role of fundamental social causes. American Journal of Public Health, 86(4), 471473.CrossRefGoogle ScholarPubMed
Long, J.S., Ervin, L.H. (2000). Using heteroscedasticity consistent standard errors in the linear regression model. American Statistician, 54(3), 217224.CrossRefGoogle Scholar
MacArthur Research Network on Socioeconomic Status and Health. (2000). John D. and Catherine T. MacArthur Research Network on Socioeconomic Status and Health Sociodemographic Questionnaire. Retrieved from http://www.macses.ucsf.edu/Research/SocialEnvironment/notebook/measure.htmlGoogle Scholar
MacLeod, C.M. (1991). Half a century of research on the Stroop effect: An integrative review. Psychology Bulletin, 109(2), 163203.CrossRefGoogle ScholarPubMed
Malecki, C.K., Demaray, M.K. (2006). Social support as a buffer in the relationship between socioeconomic status and academic performance. School Psychology Quarterly, 21(4), 375395.CrossRefGoogle Scholar
Marks, G.N. (2006). Are between- and within-school differences in student performance largely due to socio-economic background? Evidence from 30 countries. Educational Research, 48(1), 2140.CrossRefGoogle Scholar
McCabe, L.A., Cunnington, M., Brooks-Gunn, J. (2004). The development of self-regulation in young children: Individual Characteristics and environmental contexts. In R.F. Baumeister & K.D. Vohs (Eds.), Handbook of self-regulation (pp. 340357). New York: The Guilford Press.Google Scholar
McLanahan, S., Sandefur, G.D. (1994). Growing up with a single parent: What hurts, what helps. Cambridge, MA: Harvard University Press.Google Scholar
McLoyd, V.C. (1998). Socioeconomic disadvantage and child development. The American Psychologist, 53(2), 185204.CrossRefGoogle ScholarPubMed
Mercy, J.A., Steelman, L.C. (1982). Familial influence on the intellectual attainment of children. American Sociological Review, 47(4), 532542.CrossRefGoogle Scholar
Mezzacappa, E. (2004). Alerting, orienting, and executive attention: Developmental properties and sociodemographic correlates in an epidemiological sample of young, urban children. Child Development, 75(5), 13731386.CrossRefGoogle Scholar
Miller, E.K., Cohen, J.D. (2001). An integrative theory of prefrontal cortex function. Annual Review of Neuroscience, 24, 167202.CrossRefGoogle ScholarPubMed
Navarro, V. (2007). Neoliberalism, globalization, and inequalities: Consequences for health and quality of life. Amityville, NY: Baywood Publishers.Google Scholar
Noble, K.G., Farah, M.J., McCandliss, B.D. (2006). Socioeconomic background modulates cognition-achievement relationships in reading. Cognitive Development, 21(3), 349368.CrossRefGoogle ScholarPubMed
Noble, K.G., McCandliss, B.D., Farah, M.J. (2007). Socioeconomic gradients predict individual differences in neurocognitive abilities. Developmental Science, 10(4), 464480.CrossRefGoogle ScholarPubMed
Noble, K.G., Norman, M.F., Farah, M.J. (2005). Neurocognitive correlates of socioeconomic status in kindergarten children. Developmental Science, 8(1), 7487.CrossRefGoogle ScholarPubMed
Noble, K.G., Wolmetz, M.E., Ochs, L.G., Farah, M.J., McCandliss, B.D. (2006). Brain-behavior relationships in reading acquisition are modulated by socioeconomic factors. Developmental Science, 9(6), 642654.CrossRefGoogle ScholarPubMed
Parker, M.D. (2005). A comparative study between mean length of utterance in morphemes (MLUm) and mean length of utterance in words (MLUw). First Language, 25(3), 365376.CrossRefGoogle Scholar
Pennington, B.F., Ozonoff, S. (1996). Executive functions and developmental psychopathology. Journal of Child Psychology and Psychiatry, and Allied Disciplines, 37(1), 5187.CrossRefGoogle ScholarPubMed
Raviv, T., Kessenich, M., Morrison, F.J. (2004). A mediational model of the association between socioeconomic status and three-year-old language abilities: The role of parenting factors. Early Childhood Research Quarterly, 19(4), 528547.CrossRefGoogle Scholar
Ricciuti, H.N. (2004). Single parenthood, achievement, and problem behavior in White, Black, and Hispanic children. The Journal of Educational Research, 97(4), 196206.CrossRefGoogle Scholar
Rose, G. (1985). Sick individuals and sick populations. Bulletin of the World Health Organization, 79(10), 990996.Google Scholar
Rueda, M.R., Posner, M.I., Rothbart, M.K. (2005). The development of executive attention: Contributions to the emergence of self-regulation. Developmental Neuropsychology, 28(2), 573594.CrossRefGoogle Scholar
Rutter, M. (2006). Genes and behavior: Nature-nurture interplay explained. Oxford, UK: Blackwell Publishing.Google Scholar
Sarsour, K. (2007). Family socioeconomic status and child neurocognitive functions in population health perspective. Social inequalities in early neurodevelopment: Mediation and effect modification in population health perspective (pp. 36–63) (Doctoral Dissertation). University of California, Berkeley, Berkeley.Google Scholar
Seguin, J.R., Zelazo, P.D. (2005). Executive function in early physical aggression. In R.E. Tremblay, W.W. Hartup & J. Archer (Eds.), Developmental origins of aggression (pp. 307329). New York, NY: Guilford Press.Google Scholar
Shimamura, A.P. (2000). The role of the prefrontal cortex in dynamic filtering. Psychobiology, 28(2), 207218.CrossRefGoogle Scholar
Smith, E.E., Jonides, J. (1997). Working memory: A view from neuroimaging. Cognitive Psychology, 33(1), 542.CrossRefGoogle ScholarPubMed
Stevens, C., Lauinger, B., Neville, H. (2009). Differences in the neural mechanisms of selective attention in children from different socioeconomic backgrounds: An event-related brain potential study. Developmental Science, 12(4), 634646.CrossRefGoogle ScholarPubMed
Strauss, E., Sherman, E.M.S., Spreen, O. (2006). A compendium of neuropsychological tests: Administration, norms, and commentary (3rd ed.). New York: Oxford University Press.Google Scholar
Toutkoushian, R.K., Curtis, T. (2005). Effects of socioeconomic factors on public high school outcomes and rankings. Journal of Educational Research, 98(5), 259271.CrossRefGoogle Scholar
Turkheimer, E., Haley, A., Waldron, M., D’Onofrio, B., Gottesman, I.I. (2003). Socioeconomic status modifies heritability of IQ in young children. Psychological Science, 14(6), 623628.CrossRefGoogle ScholarPubMed
Tuvblad, C., Grann, M., Lichtenstein, P. (2006). Heritability for adolescent antisocial behavior differs with socioeconomic status: Gene-environment interaction. Journal of Child Psychology and Psychiatry, 47(7), 734743.CrossRefGoogle ScholarPubMed
Vakil, E., Blachstein, H., Sheinman, M., Greenstein, Y. (2009). Developmental changes in attention tests norms: Implications for the structure of attention. Child Neuropsychology, 15(1), 2139.CrossRefGoogle ScholarPubMed
Vygotsky, L.S., Kozulin, A. (1986). Thought and language (Translation newly rev. and edited / ed.). Cambridge, MA: MIT Press.Google Scholar
Walker, D., Greenwood, C., Hart, B., Carta, J. (1994). Prediction of school outcomes based on early language production and socioeconomic factors. Child Development, 65(2 Spec No), 606621.CrossRefGoogle ScholarPubMed
Wechsler, D. (1994). Wechsler Intelligence Scale for Children (3rd ed.). London: Psychological Corporation.Google Scholar
Winsler, A., Diaz, R.M., Atencio, D.J., McCarthy, E.M., Chabay, L.A. (2000). Verbal self-regulation over time in preschool children at risk for attention and behavior problems. Journal of Child Psychology and Psychiatry, and Allied Disciplines, 41(7), 875886.CrossRefGoogle ScholarPubMed
Zivin, G. (1979). The development of self-regulation through private speech. New York: Wiley.Google Scholar