John C DeFries

Articles

DeFries, J.C., Touchberry, R.W., & Hays, R.L. (1959). Heritability of the length of the gestation period in dairy cattle. Journal of Dairy Science, 42, 598-606.

DeFries, J.C., Touchberry, R.W., & Hays, R.L. (1960). Changing the length of the gestation period in dairy cattle. Illinois Research, 2(1), 19.

DeFries, J.C., & Touchberry, R.W. (1961). A "maternal effect" on body weight in Drosophila. Genetics, 46, 1261-1266.

DeFries, J.C., & Touchberry, R.W. (1961). The variability of response to selection: I. Interline and intraline variability in a population of Drosophila affinis selected for body weight. Genetics, 46, 1519-1530.

Weir, M.W., & DeFries, J.C. (1963). Blocking of pregnancy in mice as a function of stress. Psychological Reports, 13, 365-366.

DeFries, J.C. (1964). Prenatal maternal stress in mice: Differential effects on behavior. Journal of Heredity, 55, 289-295. Reprinted in M. Manosevitz, G. Lindzey, & D.D. Thiessen, Eds. (1969), Behavioral genetics: Methods and research (pp. 528-537). New York: Appleton-Century-Crofts.

DeFries, J.C., & Weir, M.W. (1964). Open-field behavior of C57BL/6J mice as a function of age, experience, and prenatal maternal stress. Psychonomic Science,1, 389-390.

Touchberry, R.W., & DeFries, J.C. (1964). Genetic effects of gamma-irradiation on egg production and adult emergence of Drosophila melanogaster. Genetics, 49, 387-400.

Weir, M.W., & DeFries, J.C. (1964). Prenatal maternal influence on behavior in mice: Evidence of a genetic basis. Journal of Comparative and Physiological Psychology, 58, 412-417.

DeFries, J.C., Weir, M.W., & Hegmann, J.P. (1965). Blocking of pregnancy in mice as a function of stress: Supplementary note. Psychological Reports, 17, 96-98.

DeFries, J.C., Hegmann, J.P., & Weir, M.W. (1966). Open-field behavior in mice: Evidence for a major gene effect mediated by the visual system. Science, 154, 1577-1579. Reprinted in M. Manosevitz, G. Lindzey, & D.D. Thiessen, Eds. (1969), Behavioral genetics: Methods and research (pp. 211-215). New York: Appleton-Century-Crofts.

DeFries, J.C. (1967). Effects of heredity and prenatal stress on behavior of offspring. Illinois Research, 9, 6-7.

DeFries, J.C., Thomas, E.A., Hegmann, J.P., & Weir, M.W. (1967). Open-field behavior in mice: Analysis of maternal effects by means of ovarian transplantation. Psychonomic Science, 8, 207-208.

DeFries, J.C., Weir, M.W., & Hegmann, J.P. (1967). Differential effects of prenatal maternal stress on offspring behavior in mice as a function of genotype and stress. Journal of Comparative and Physiological Psychology, 63, 332-334. Reprinted in T.E. McGill, Ed. (1973), Readings in animal behavior (2nd ed., pp. 211-213). New York: Holt, Rinehart and Winston.

McReynolds, W.E., Weir, M.W., & DeFries, J.C. (1967). Open-field behavior in mice: Effect of test illumination. Psychonomic Science, 9, 277-278.

Dixon, L.K., & DeFries, J.C. (1968). Development of open-field behavior in mice: Effects of age and experience. Developmental Psychobiology, 1, 100-107.

Dixon, L.K., & DeFries, J.C. (1968). Effects of illumination on open-field behavior in mice. Journal of Comparative and Physiological Psychology, 66, 803-805.

Hegmann, J.P., & DeFries, J.C. (1968). Open-field behavior in mice: Genetic analysis of repeated measures. Psychonomic Science, 13, 27-28.

DeFries, J.C. (1969). Pleiotropic effects of albinism on open-field behavior in mice. Nature, 221, 65-66.

DeFries, J.C., Hegmann, J.P., Ross, D.B., & Howard, M.K. (1969). A quantitative genetic analysis of change in open-field behavior of mice. Psychonomic Science, 17, 153-154.

DeFries, J.C., & McClearn, G.E. (1970). Social dominance and Darwinian fitness in the laboratory mouse. American Naturalist, 104, 408-411.

DeFries, J.C., Wilson, J.R., & McClearn, G.E. (1970). Open-field behavior in mice: Selection response and situational generality. Behavior Genetics, 1, 195-211.

Hegmann, J.P., & DeFries, J.C. (1970). Are genetic correlations and environmental correlations correlated? Nature, 226, 284-286.

Hegmann, J.P., & DeFries, J.C. (1970). Maximum variance linear combinations from phenotypic, genetic, and environmental covariance matrices. Multivariate Behavioral Research, 5, 9-18.

Klein, T.W., & DeFries, J.C. (1970). Similar polymorphisms of taste sensitivity to PTC in mice and men. Nature, 225, 555-557.

Klein, T.W., & DeFries, J.C. (1970). Taste sensitivity in infrahuman species: Use of a genetic model to test the validity of alternative measures. Behavior Research Methods and Instrumentation, 2, 106-107.

Klein, T.W., Howard, J., & DeFries, J.C. (1970). Agonistic behavior in mice: Strain differences as a function of test illumination. Psychonomic Science, 19, 177-178.

Vandenberg, S.G., & DeFries, J.C. (1970). Our hopes for Behavior Genetics. Behavior Genetics, 1, 1-2.

Whitney, G., McClearn, G.E., & DeFries, J.C. (1970). Heritability of alcohol preference in laboratory mice and rats. Journal of Heredity, 61, 165-169.

Klein, T.W., & DeFries, J.C. (1973). Racial and cultural differences in sensitivity to flickering light. Social Biology, 20, 212-217.

Klein, T.W., DeFries, J.C., & Finkbeiner, C.T. (1973). Heritability and genetic correlation: Standard errors of estimates and sample size. Behavior Genetics, 3, 355-364.

DeFries, J.C., Hegmann, J.P., & Halcomb, R.A. (1974). Response to 20 generations of selection for open-field activity in mice. Behavioral Biology, 11, 481-495.

DeFries, J.C., Vandenberg, S.G., McClearn, G.E., Kuse, A.R., Wilson, J.R., Ashton, G.C., & Johnson, R.C. (1974). Near identity of cognitive structure in two ethnic groups. Science, 183, 338-339.

Padeh, B., Wahlsten, D., & DeFries, J.C. (1974). Operant discrimination learning and operant bar-pressing rates in inbred and heterogeneous laboratory mice. Behavior Genetics, 4, 383-393.

Halcomb, R.A., Hegmann, J.P., & DeFries, J.C. (1975). Open-field behavior in mice: A diallel analysis of selected lines. Behavior Genetics, 5, 217-231.

Wilson, J.R., DeFries, J.C., McClearn, G.E., Vandenberg, S.G., Johnson, R.C., & Rashad, M.N. (1975). Cognitive abilities: Use of family data as a control to assess sex and age differences in two ethnic groups. International Journal of Aging and Human Development, 6, 261-276.

Deckard, B.S., Lieff, B., Schlesinger, K., & DeFries, J.C. (1976). Developmental patterns of seizure susceptibility in inbred strains of mice. Developmental Psychobiology, 9, 17-24.

DeFries, J.C., Ashton, G.C., Johnson, R.C., Kuse, A.R., McClearn, G.E., Mi, M.P., Rashad, M.N., Vandenberg, S.G., & Wilson, J.R. (1976). Parent-offspring resemblance for specific cognitive abilities in two ethnic groups. Nature, 261, 131-133.

DeFries, J.C., Vandenberg, S.G., & McClearn, G.E. (1976). Genetics of specific cognitive abilities. Annual Review of Genetics, 10, 179-207.

Johnson, R.C., DeFries, J.C., Wilson, J.R., McClearn, G.E., Vandenberg, S.G., Ashton, G.C., Mi, M.P., & Rashad, M.N. (1976). Assortative marriage for specific cognitive abilities in two ethnic groups. Human Biology, 48, 343-352.

Johnson, R.C., Park, J., DeFries, J.C., McClearn, G.E., Mi, M.P., Rashad, M.N., Vandenberg, S.G., & Wilson, J.R. (1976). Assortative marriage for specific cognitive abilities in Korea. Social Biology, 23, 311-316.

Kuse, A.R., & DeFries, J.C. (1976). Social dominance and Darwinian fitness in laboratory mice: An alternative test. Behavioral Biology, 16, 113-116.

Plomin, R., & DeFries, J.C. (1976). Letter in response to "The Heritability Hang-up," by M. Feldman & R.C. Lewontin. Science, 194, 10-12.

Foch, T.T., DeFries, J.C., McClearn, G.E., & Singer, S.M. (1977). Familial patterns of impairment in reading disability. Journal of Educational Psychology, 69, 316-329.

Gervais, M.C., DeFries, J.C., & Kuse, A.R. (1977). Open-field behavior in mice: Effect of litter size. Behavioral Biology, 20, 519-522.

Hewitt, J.K., Fulker, D.W., & DeFries, J.C. (1977). Open-field behavior in mice: Generality of results from a diallel analysis of replicate selected lines. Behavior Genetics, 7, 441-446.

Plomin, R., DeFries, J.C., & Loehlin, J.C. (1977). Genotype-environment interaction and correlation in the analysis of human behavior. Psychological Bulletin, 84, 309-322.

Plomin, R., DeFries, J. ., & Roberts, M.K. (1977). Assortative mating by unwed biological parents of adopted children. Science, 196, 449-450.

Crawford, C.B., & DeFries, J.C. (1978). Factor analysis of genetic and environmental correlation matrices. Multivariate Behavioral Research, 13, 297-318.

DeFries, J.C. (1978). "Heritability estimates" from family data. Behavior Genetics, 8, 481-482.

DeFries, J.C., Ashton, G.C., Johnson, R.C., Kuse, A.R., McClearn, G.E., Mi, M.P., Rashad, M.N., Vandenberg, S.G., & Wilson, J. . (1978). The Hawaii family study of cognition: A reply. Behavior Genetics, 8, 281-288.

DeFries, J.C., Gervais, M.C., & Thomas, E.A . (1978). Response to 30 generations of selection for open-field activity in laboratory mice. Behavior Genetics, 8, 3-13.

DeFries, J.C. & Plomin, R. (1978). Behavioral genetics. Annual Review of Psychology, 29, 473-515.

DeFries, J.C., Singer, S.M., Foch, T.T., & Lewitter, F.I. (1978). Familial nature of reading disability. British Journal of Psychiatry, 132, 361-367.

Park, J., Johnson, R.C., DeFries, J.C., McClearn, G.E., Mi, M.P., Rashad, M.N., Vandenberg, S.G., & Wilson, J.R. (1978). Parent-offspring resemblance for specific cognitive abilities in Korea. Behavior Genetics, 8, 43-52.

DeFries, J.C., Johnson, R.C., Kuse, A.R., McClearn, G.E., Polovina, J., Vandenberg, S.G., & Wilson, J.C. (1979). Familial resemblance for specific cognitive abilities. Behavior Genetics, 9, 23-43.

Ho, H-Z., Plomin, R., & DeFries, J.C. (1979). Selective placement in adoption. Social Biology, 26, 1-6.

Plomin, R., & DeFries, J.C. (1979). Multivariate behavioral genetic analysis of twin data on scholastic abilities. Behavior Genetics, 9, 505- 517.

Corley, R.P., DeFries, J.C., Kuse, A.R., & Vandenberg, S.G. (1980). Familial resemblance for the Identical Blocks test of spatial ability: No evidence for X-linkage. Behavior Genetics, 10, 211-215.

Decker, S.N., & DeFries, J.C. (1980). Cognitive abilities in families with reading disabled children. Journal of Learning Disabilities, 13, 517-522.

George, F.R., O'Connor, M.F., DeFries, J.C., & Collins, A.C. (1980). Components of the GABA system in mice selectively bred for differences in open-field activity. Brain Research, 200, 85-92.

Lewitter, F.I., DeFries, J.C., & Elston, R.C. (1980). Genetic models of reading disability. Behavior Genetics, 10, 9-30.

Plomin, R., & DeFries, J.C. (1980). Genetics and intelligence: Recent data. Intelligence, 4, 15-24.

Decker, S. N., & DeFries, J. C. (1981). Cognitive ability profiles in families of reading-disabled children.Developmental Medicine and Child Neurology, 23, 217-227.

DeFries, J.C., Plomin, R., Vandenberg, S.G., & Kuse, A.R. (1981). Parent-offspring resemblance for cognitive abilities in the Colorado Adoption Project: Biological, adoptive, and control parents and one-year-old children. Intelligence, 5, 245-277.

Hardy-Brown, K., Plomin, R., & DeFries, J.C. (1981). Genetic and environmental influences on the rate of communicative development in the first year of life. Developmental Psychology, 17, 704-717.

DeFries, J.C., Corley, R.P., Johnson, R.C., Vandenberg, S.G., & Wilson, J.R. (1982). Sex-by-generation and ethnic group-by-generation interactions in the Hawaii family study of cognition. Behavior Genetics, 12, 223-230.

Whitney, G., McClearn, G.E., & DeFries, J.C. (1982). Heritability of alcohol preference in laboratory mice and rats: Erroneous estimates. Behavior Genetics, 12, 543-546.

Baker, L.A., DeFries, J.C., & Fulker, D.W. (1983). Longitudinal stability of cognitive ability in the Colorado Adoption Project. Child Development, 54, 290-297.

DeFries, J.C., & Baker, L.A. (1983). Colorado Family Reading Study: Longitudinal analyses. Annals of Dyslexia, 33, 153-162.

DeFries, J.C., & Baker, L.A. (1983). Parental contributions to longitudinal stability in the Colorado Family Reading Study. Child Development, 54, 388-395.

Fulker, D.W., & DeFries, J.C. (1983). Genetic and environmental transmission in the Colorado Adoption Project: Path analysis. British Journal of Mathematical and Statistical Psychology, 36, 175-188.

Johnson, R., Nagoshi, C.T., Ahern, F.M., Wilson, J.R., DeFries, J.C., McClearn, G.E., & Vandenberg, S.G. (1983). Family background, cognitive ability, and personality as predictors of educational and occupational attainment. Social Biology, 30, 86-100.

Plomin, R., & DeFries, J.C. (1983). The Colorado Adoption Project. Child Development, 54, 276-289.

Vogler, G.P., & DeFries, J.C. (1983). Linearity of offspring-parent regression for general cognitive ability. Behavior Genetics, 13, 355-360.

Baker, L.A., Decker, S.N., & DeFries, J.C. (1984). Cognitive abilities in reading-disabled children: A longitudinal study. The Journal of Child Psychology and Psychiatry and Allied Disciplines, 25, 111-117.

Nagoshi, C.T., Johnson, R.C., DeFries, J.C., Wilson, J.R., & Vandenberg, S.G. (1984). Group differences and first principal component loadings in the Hawaii Family Study of Cognition: A test of the generality of "Spearman's hypothesis." Personality and Individual Differences, 5, 751-753.

Rice, T., Plomin, R., & DeFries, J.C. (1984). Development of hand preference in the Colorado Adoption Project. Perceptual and Motor Skills, 58, 683-689.

Vogler, G.P., DeFries, J.C., & Decker, S.N. (1984). Family history as an indicator of risk for reading disability. Journal of Learning Disabilities, 17, 616-618. (Reprinted in Journal of Learning Disabilities, 1985, 18, 419-421.)

Wilson, J.R., Erwin, V.G., DeFries, J.C., Petersen, D.R., & Cole-Harding, S. (1984). Ethanol dependence in mice: Direct and correlated responses to ten generations of selective breeding. Behavior Genetics, 14, 235-256.

Bennett, B., Fulker, D.W., & DeFries, J.C. (1985). Familial resemblance for general cognitive ability in the Hawaii Family Study of Cognition. Behavior Genetics, 15, 401-406.

DeFries, J.C., & Fulker, D.W. (1985). Multiple regression analysis of twin data. Behavior Genetics, 15, 467-473.

LaBuda, M.C., Vogler, G.P., DeFries, J.C., & Fulker, D.W. (1985). Multivariate familial analysis of cognitive measures in the Colorado Family Reading Study. Multivariate Behavioral Research, 20, 357-368.

Plomin, R., & DeFries, J.C. (1985). A parent-offspring adoption study of cognitive abilities in early childhood. Intelligence, 9, 341-356.

Plomin, R., Loehlin, J.C., & DeFries, J.C. (1985). Genetic and environmental components of "environmental" influences. Developmental Psychology, 21, 391-402.

Thompson, L.A., Plomin, R., & DeFries, J.C. (1985). Parent-infant resemblance for general and specific cognitive abilities in the Colorado Adoption Project. Intelligence, 9, 1-13.

Vogler, G.P., & DeFries, J.C. (1985). Bivariate path analysis of familial resemblance for reading ability and symbol processing speed. Behavior Genetics, 15, 111-121.

DeFries, J.C., & Fulker, D.W. (1986). Multivariate behavioral genetics and development. Behavior Genetics, 16, 1-10.

LaBuda, M.C., DeFries, J.C., & Fulker, D.W. (1986). Multiple regression analysis of twin data obtained from selected samples. Genetic Epidemiology, 3, 425-433.

LaBuda, M.C., DeFries, J.C., Plomin, R., & Fulker, D.W. (1986). Longitudinal stability of cognitive ability from infancy to early childhood: Genetic and environmental etiologies. Child Development, 57, 1142-1150.

Rice, T., Fulker, D.W., & DeFries, J.C. (1986). Multivariate path analysis of specific cognitive abilities in the Colorado Adoption Project. Behavior Genetics, 16, 107-125.

Thompson, L.A., Fulker, D.W., DeFries, J.C., & Plomin, R. (1986). Multivariate genetic analysis of "environmental" influences on infant cognitive development. British Journal of Developmental Psychology, 4, 347-353.

Vogler, G.P., & DeFries, J.C. (1986). Multivariate path analysis of cognitive ability measures in reading-disabled and control nuclear families and twins. Behavior Genetics, 16, 89-106.

DeFries, J.C., Fulker, D.W., & LaBuda, M.C. (1987). Evidence for a genetic aetiology in reading disability of twins. Nature, 329, 537-539.

DeFries, J.C., Plomin, R., & LaBuda, M.C. (1987). Genetic stability of cognitive development from childhood to adulthood. Developmental Psychology, 23, 4-12.

LaBuda, M.C., DeFries, J.C., & Fulker, D.W. (1987). Genetic and environmental covariance structures among WISC-R subtests: A twin study. Intelligence, 11, 233-244.

Loehlin, J.C., & DeFries, J.C. (1987). Genotype-environment correlation and IQ. Behavior Genetics, 17, 263-277.

Zieleniewski, A.M., Fulker, D.W., DeFries, J.C., & LaBuda, M.C. (1987). Multiple regression analysis of twin and sibling data. Personality and Individual Differences, 8, 787-791.

Bergeman, C.S., Plomin, R., DeFries, J.C., & Fulker, D.W. (1988). Path analysis of general and specific cognitive abilities in the Colorado Adoption Project: Early childhood. Personality and Individual Differences, 9, 391-395.

DeFries, J.C. (1988). Colorado Reading Project: Longitudinal analyses. Annals of Dyslexia, 38, 120-130.

DeFries, J.C., & Fulker, D.W. (1988). Multiple regression analysis of twin data: Etiology of deviant scores versus individual differences. Acta Geneticae Medicae et Gemellologiae: Twin Research, 37, 205-216.

Fulker, D.W., DeFries, J.C., & Plomin, R. (1988). Genetic influence on general mental ability increases between infancy and middle childhood. Nature, 336, 767-769.

LaBuda, M.C., & DeFries, J.C. (1988). Cognitive abilities in children with reading disabilities and controls: A follow-up study. Journal of Learning Disabilities, 21, 562-566.

LaBuda, M.C., & DeFries, J.C. (1988). Genetic and environmental etiologies of reading disability: A twin study. Annals of Dyslexia, 38, 131-138.

Rice, T., Fulker, D.W., DeFries, J.C., & Plomin, R. (1988). Path analysis of IQ during infancy and early childhood and an index of the home environment in the Colorado Adoption Project. Intelligence, 12, 27-45.

Thompson, L.A., Fulker, D.W., DeFries, J.C., & Plomin, R. (1988). Multivariate analysis of cognitive and temperament measures in 24-month-old adoptive and nonadoptive sibling pairs. Personality and Individual Differences, 9, 95-100.

Cyphers, L.H., Fulker, D.W., Plomin, R., & DeFries, J.C. (1989). Cognitive abilities in the early school years: No effects of shared environment between parents and offspring. Intelligence, 13, 369-386.

Decker, S.N., Vogler, G.P., & DeFries, J.C. (1989). Validity of self-reported reading disability by parents of reading-disabled and control children. Reading and Writing: An Interdisciplinary Journal, 1, 327-331.

DeFries, J.C. (1989). Gender ratios in children with reading disability and their affected relatives: A commentary. Journal of Learning Disabilities, 22, 544-555.

DeFries, J.C., Wilson, J.R., Erwin, V.G., & Petersen, D.R. (1989). LSXSS recombinant inbred strains of mice: Initial characterization. Alcoholism: Clinical and Experimental Research, 13, 196-200.

Gillis, J.J., & DeFries, J.C. (1989). Validity of school history as a diagnostic criterion for reading disability. Reading and Writing: An Interdisciplinary Journal, 1, 93-101.

LaBuda, M.C., & DeFries, J.C. (1989). Differential prognosis of reading-disabled children as a function of gender, socioeconomic status, IQ, and severity: A longitudinal study. Reading and Writing: An Interdisciplinary Journal, 1, 25-36.

Rice, T., Carey, G., Fulker, D.W., & DeFries, J.C. (1989). Multivariate path analysis of specific cognitive abilities in the Colorado Adoption Project: Conditional path model of assortative mating. Behavior Genetics, 19, 195-207.

Vogler, G.P., Baker, L.A., Decker, S.N., DeFries, J.C., & Huizinga, D.H. (1989). Cluster analytic classification of reading disability subtypes. Reading and Writing: An Interdisciplinary Journal, 1, 163-177.

Wadsworth, S.J., Gillis, J.J., DeFries, J.C., & Fulker, D.W. (1989). Differential genetic aetiology of reading disability as a function of age. The Irish Journal of Psychology, 10, 509-520.

Brooks, A., Fulker, D.W., & DeFries, J.C. (1990). Reading performance and general cognitive ability: A multivariate genetic analysis of twin data. Personality and Individual Differences, 11, 141-146.

Cardon, L.R., DiLalla, L.F., Plomin, R., DeFries, J.C., & Fulker, D.W. (1990). Genetic correlations between reading performance and IQ in the Colorado Adoption Project. Intelligence, 14, 245-257.

Coon, H., Fulker, D.W., DeFries, J.C., & Plomin, R. (1990). Home environment and cognitive ability of 7-year-old children in the Colorado Adoption Project: Genetic and environmental etiologies. Developmental Psychology, 26, 459-468.

DeFries, J.C., Wadsworth, S.J., & Gillis, J.J. (1990). Gender differences in cognitive abilities of reading-disabled twins. Annals of Dyslexia, 40, 216-228.

LaBuda, M.C., DeFries, J.C., & Pennington, B.F. (1990). Reading disability: A model for the genetic analysis of complex behavioral disorders. Journal of Counseling and Development, 68, 645-651.

Plomin, R., Corley, R., DeFries, J.C., & Fulker, D.W. (1990). Individual differences in television viewing in early childhood: Nature as well as nurture. Psychological Science, 1, 371-377.

DeFries, J.C., Olson, R.K., Pennington, B.F., & Smith, S.D. (1991). Colorado Reading Project: Past, present, and future. Learning Disabilities: A Multidisciplinary Journal, 2, 37-46.

DeFries, J.C., Stevenson, J., Gillis, J.J., & Wadsworth, S.J. (1991). Genetic etiology of spelling deficits in the Colorado and London twin studies of reading disability. Reading and Writing: An Interdisciplinary Journal, 3, 271-283. [Reprinted in B. F. Pennington (Ed.), Reading disabilities: Genetic and neurological influences (pp. 83-95). Dordrecht, The Netherlands: Kluwer Academic Publishers.]

Fulker, D.W., Cardon, L.R., DeFries, J.C., Kimberling, W.J., Pennington, B.F., & Smith, S.D. (1991). Multiple regression analysis of sib-pair data on reading to detect quantitative trait loci. Reading and Writing: An Interdisciplinary Journal, 3, 299-313. [Reprinted in B.F. Pennington (Ed.), Reading disabilities: Genetic and neurological influences (pp. 111-125). Dordrecht, The Netherlands: Kluwer Academic Publishers.]

Gilger, J.W., Pennington, B.F., & DeFries, J.C. (1991). Risk for reading disability as a function of parental history in three family studies. Reading and Writing: An Interdisciplinary Journal, 3, 205-217. [Reprinted in B.F. Pennington (Ed.), Reading disabilities: Genetic and neurological influences (pp. 17-29). Dordrecht, The Netherlands: Kluwer Academic Publishers.]

Olson, R.K., Gillis, J.J., Rack, J.P., DeFries, J.C., & Fulker, D.W. (1991). Confirmatory factor analysis of word recognition and process measures in the Colorado Reading Project. Reading and Writing: An Interdisciplinary Journal, 3, 235-248. [Reprinted in B.F. Pennington (Ed.), Reading disabilities: Genetic and neurological influences (pp. 47-60). Dordrecht, The Netherlands: Kluwer Academic Publishers.]

Pennington, B.F., Gilger, J.W., Pauls, D., Smith, S.A., Smith, S.D., & DeFries, J.C. (1991). Evidence for major gene transmission of developmental dyslexia. Journal of the American Medical Association, 266, 1527-1534.

Plomin, R., Coon, H., Carey, G., DeFries, J.C., & Fulker, D.W. (1991). Parent-offspring and sibling adoption analyses of parental ratings of temperament in infancy and childhood. Journal of Personality, 59, 705-732.

Braungart, J.M., Plomin, R., DeFries, J.C., & Fulker, D.W. (1992). Genetic influence on tester-rated infant temperament as assessed by Bayley's Infant Behavior Record: Nonadoptive and adoptive siblings and twins. Developmental Psychology, 28, 40-47.

Cardon, L.R., Corley, R.P., DeFries, J.C., Plomin, R., & Fulker, D.W. (1992). Factorial validation of a telephone test battery of specific cognitive abilities. Personality and Individual Differences, 13, 1047-1050.

Cardon, L.R., Fulker, D.W., DeFries, J.C., & Plomin, R. (1992). Continuity and change in general cognitive ability from 1 to 7 years of age. Developmental Psychology, 28, 64-73.

Cardon, L.R., Fulker, D.W., DeFries, J.C., & Plomin, R. (1992). Multivariate genetic analysis of specific cognitive abilities in the Colorado Adoption Project at Age 7. Intelligence, 16, 383-400.

Cherny, S.S., Cardon, L.R., Fulker, D.W., & DeFries, J.C. (1992). Differential heritability across levels of cognitive ability. Behavior Genetics, 22, 153-162.

Cherny, S.S., DeFries, J.C., & Fulker, D.W. (1992). Multiple regression analysis of twin data: A model-fitting approach. Behavior Genetics, 22, 489-497.

Emde, R.N., Plomin, R., Robinson, J., Corley, R., DeFries, J., Fulker, D.W., Reznick, J.S., Campos, J., Kagan, J., & Zahn-Waxler, C. (1992). Temperament, emotion, and cognition at fourteen months: The MacArthur Longitudinal Twin Study. Child Development, 63, 1437-1455.

Gilger, J.W., Pennington, B.F., & DeFries, J.C. (1992). A twin study of the etiology of comorbidity: Attention-deficit hyperactivity disorder and dyslexia. Journal of the American Academy of Child and Adolescent Psychiatry, 31, 343-348.

Gillis, J.J., DeFries, J.C., & Fulker, D.W. (1992). Confirmatory factor analysis of reading and mathematics performance: A twin study. Acta Geneticae Medicae et Gemellologiae, 41, 287-300.

Gillis, J.J., Gilger, J.W., Pennington, B.F., & DeFries, J.C. (1992). Attention-deficit disorder in reading-disabled twins: Evidence for a genetic etiology. Journal of Abnormal Child Psychology, 20, 303-315.

Johnson, T.E., DeFries, J.C., & Markel, P.D. (1992). Mapping quantitative trait loci for behavioral traits in the mouse. Behavior Genetics, 22, 635-653.

Pennington, B.F., Gilger, J.W., Olson, R.K., & DeFries, J.C. (1992). The external validity of age- versus IQ-discrepancy definitions of reading disability: Lessons from a twin study. Journal of Learning Disabilities, 25, 562-573.

Wadsworth, S.J., DeFries, J.C., Stevenson, J., Gilger, J.W., & Pennington, B.F. (1992). Gender ratios among reading-disabled children and their siblings as a function of parental impairment. Journal of Child Psychology and Psychiatry, 33, 1229-1239.

Waldman, I.D., DeFries, J.C., & Fulker, D.W. (1992). Quantitative genetic analysis of IQ development in young children: Multivariate multiple regression with orthogonal polynomials. Behavior Genetics, 22, 229-238.

Coon, H., Carey, G., Fulker, D.W., & DeFries, J.C. (1993). Influences of school environment on the academic achievement scores of adopted and nonadopted children. Intelligence, 17, 79-104.

Mitton, J.B., Schuster, W.S.F., Cothran, E.G., & DeFries, J.C. (1993). Correlation between the individual heterozygosity of parents and their offspring. Heredity, 71, 59-63.

Plomin, R., Emde, R.N., Braungart, J.M., Campos, J., Corley, R., Fulker, D.W., Kagan, J., Reznick, J.S., Robinson, J., Zahn-Waxler, C., & DeFries, J.C. (1993). Genetic change and continuity from 14 to 20 months: The MacArthur Longitudinal Twin Study. Child Development, 64, 1354-1376.

Stevenson, J., Pennington, B.F., Gilger, J.W., DeFries, J.C., & Gillis, J.J. (1993). Hyperactivity and spelling disability: Testing for shared genetic aetiology. Journal of Child Psychology and Psychiatry, 34, 1137-1152.

Wadsworth, S.J., DeFries, J.C., & Fulker, D.W. (1993). Cognitive abilities of children at 7 and 12 years of age in the Colorado Adoption Project. Journal of Learning Disabilities, 26, 611-615.

Alarcón, M., DeFries, J.C., & Gillis, J.J. (1994). Familial resemblance for measures of reading performance in families of reading-disabled and control twins. Reading and Writing: An Interdisciplinary Journal, 6, 93-101.

Cardon, L.R., Smith, S.D., Fulker, D.W., Kimberling, W.J., Pennington, B.F., & DeFries, J.C. (1994). Quantitative trait locus for reading disability on chromosome 6. Science, 266, 276-279.

Cherny, S.S., Fulker, D.W., Corley, R.P., Plomin, R., & DeFries, J.C. (1994). Continuity and change in infant shyness from 14 to 20 months. Behavior Genetics, 24, 365-379.

Cherny, S.S., Fulker, D.W., Emde, R.N., Robinson, J., Corley, R.P., Reznick, J.S., Plomin, R., & DeFries, J.C. (1994). A developmental-genetic analysis of continuity and change in the Bayley Mental Development index from 14 to 24 months: The MacArthur Longitudinal Twin Study. Psychological Science, 5, 354-360.

Gilger, J.W., Borecki, I.B., DeFries, J.C., & Pennington, B.F. (1994). Commingling and segregation analysis of reading performance in families of normal reading probands. Behavior Genetics, 24, 345-355.

Smolen, A., Marks, M.J., DeFries, J.C., & Henderson, N.D. (1994). Individual differences in sensitivity to nicotine in mice: Response to six generations of selective breeding. Pharmacology Biochemistry and Behavior, 49, 531-540.

Alarcón, M., DeFries, J.C., Fulker, D.W. (1995). Etiology of individual differences in reading performance: A test of sex-limitation. Behavior Genetics, 25, 17-23.

Braungart-Rieker, J., Rende, R.D., Plomin, R., DeFries, J.C., & Fulker, D.W. (1995). Genetic mediation of longitudinal associations between family environment and childhood behavior problems. Development and Psychopathology, 7, 233-245.

Casto, S.D., DeFries, J.C., & Fulker, D.W. (1995). Multivariate genetic analysis of Wechsler Intelligence Scale for Children-Revised (WISC-R) factors. Behavior Genetics, 25, 25-32.

Flint, J., Corley, R., DeFries, J.C., Fulker, D.W., Gray, J.A., Miller, S., & Collins, A.C. (1995). A simple genetic basis for a complex psychological trait in laboratory mice. Science, 269, 1432-1435.

Light, J.G., & DeFries, J.C. (1995). Comorbidity of reading and mathematics disabilities: Genetic and environmental etiologies. Journal of Learning Disabilities, 28, 96-106.

Light, J.G., Pennington, B.F., Gilger, J.W., & DeFries, J.C. (1995). Reading disability and hyperactivity disorder: Evidence for a common genetic etiology. Developmental Neuropsychology, 11, 323-335.

Markel, P.D., DeFries, J.C., & Johnson, T.E. (1995). Ethanol-induced anesthesia in inbred strains of long-sleep and short-sleep mice: A genetic analysis of repeated measures using censored data. Behavior Genetics, 25, 67-73.

Markel, P.D., DeFries, J.C., & Johnson, T.E. (1995). Use of repeated-measures in an analysis of ethanol-induced loss of righting reflex in inbred long-sleep and short-sleep mice. Alcoholism: Clinical and Experimental Research, 19, 299-304.

Wadsworth, S.J., DeFries, J.C., Fulker, D.W., Olson, R.K., & Pennington, B.F. (1995). Reading performance and verbal short-term memory: A twin study of reciprocal causation. Intelligence, 20, 145-167.

Wadsworth, S.J., DeFries, J.C., Fulker, D.W., & Plomin, R. (1995). Cognitive ability and academic achievement in the Colorado Adoption Project: A multivariate genetic analysis of parent-offspring and sibling data. Behavior Genetics, 25, 1-15.

Wadsworth, S.J., DeFries, J.C., Fulker, D.W., & Plomin, R. (1995). Covariation among measures of cognitive ability and academic achievement in the Colorado Adoption Project: Sibling analysis. Personality and Individual Differences, 18, 63-73.

Casto, S.D., Pennington, B.F., Light, J.G., & DeFries, J.C. (1996). Differential genetic etiology of reading disability as a function of mathematics performance. Reading and Writing: An Interdisciplinary Journal, 8, 295-306.

DeFries, J.C., & Alarcón, M. (1996). Genetics of specific reading disability. Mental Retardation and Developmental Disabilities Research, 2, 39-47.

Knopik, V.S., DeFries, J.C., & Alarcón, M. (1996). Gender differences in cognitive abilities of opposite-sex and same-sex twin pairs with reading disability. Annals of Dyslexia, 46, 241-257.

Markel, P.D., Fulker, D.W., Bennett, B., Corley, R.P., DeFries, J.C., Erwin, V.G., & Johnson, T.E. (1996). Quantitative trait loci for ethanol sensitivity in the LSXSS recombinant inbred strains: Interval mapping. Behavior Genetics, 26, 447-458.

Saudino, K.J., Plomin, R., & DeFries, J.C. (1996). Tester-rated temperament at 14, 20, and 24 months: Environmental change and genetic continuity. British Journal of Developmental Psychology, 14, 129-144.

Schmitz, S., Saudino, K.J., Plomin, R., Fulker, D.W., & DeFries, J.C. (1996). Genetic and environmental influences on temperament in middle childhood: Analyses of teacher and tester ratings. Child Development, 67, 409-422.

Alarcón, M., & DeFries, J.C. (1997). Reading performance and general cognitive ability in twins with reading difficulties and control pairs. Personality and Individual Differences, 22, 793-803.

Alarcón, M., DeFries, J.C., Light, J.G., & Pennington, B.F. (1997). A twin study of mathematics disability. Journal of Learning Disabilities, 30, 617-623.

DeFries, J.C., Filipek, P.A., Fulker, D.W., Olson, R.K., Pennington, B.F., Smith, S.D., & Wise, B.W. (1997). Colorado Learning Disabilities Research Center. Learning Disabilities: A Multidisciplinary Journal, 8, 7-19.

Knopik, V.S., Alarcón, M., & DeFries, J.C. (1997). Comorbidity of mathematics and reading deficits: Evidence for a genetic etiology. Behavior Genetics, 27, 447-453.

Plomin, R., Fulker, D.W., Corley, R., & DeFries, J.C. (1997). Nature, nurture, and cognitive development from 1 to 16 years: A parent-offspring adoption study. Psychological Science, 8, 442-447.

Sherman, S.L., DeFries, J.C., Gottesman, I.I., Loehlin, J.C., Meyer, J.M., Pelias, M.Z., Rice, J., & Waldman, I. (1997). BEHAVIORAL GENETICS ‘97: ASHG STATEMENT. Recent developments in human behavioral genetics: Past accomplishments and future directions. American Journal of Human Genetics, 60, 1265-1275.

Wadsworth, S.J., Corley, R.P., DeFries, J.C., Fulker, D.W., Carey, G., & Plomin, R. (1997). Substance experimentation in the Colorado Adoption Project. Personality and Individual Differences, 23, 463-471.

Alarcón, M. Plomin, R., Fulker, D.W., Corley, R., & DeFries, J.C. (1998). Multivariate path analysis of specific cognitive abilities data at 12 years of age in the Colorado Adoption Project. Behavior Genetics, 28, 255-264.

Gilger, J.W., Pennington, B.F., Harbeck, R.J., DeFries, J.C., Kotzin, B., Green, P., & Smith, S. (1998). A twin and family study of the association between immune system dysfunction and dyslexia using blood serum immunoassay and survey data. Brain and Cognition, 36, 310-333.

Knopik, V.S., & DeFries, J.C. (1998). Common and specific gender influences on individual differences in reading performance: A twin study. Personality and Individual Differences, 25, 269-277.

Knopik, V.S., & DeFries, J.C. (1998). A twin study of gender-influenced individual differences in general cognitive ability. Intelligence, 26, 81-89.

Light, J.G., DeFries, J.C., & Olson, R.K. (1998). Multivariate behavioral genetic analysis of achievement and cognitive measures in reading-disabled and control twin pairs. Human Biology, 70, 215-237.

Plomin R., Corley, R., Caspi, A., Fulker, D.W., & DeFries, J.C. (1998). Adoption results for self-reported personality: Evidence for nonaddictive genetic effects? Journal of Personality and Social Psychology, 75, 211-218.

Plomin, R., & DeFries, J.C. (1998). The genetics of cognitive abilities and disabilities. Scientific American, 278, 62-69

Alarcón, M., Plomin, R., Fulker, D. W., Corley, R., DeFries, J.C. (1999). Molarity not modularity: Multivariate genetic analysis of specific cognitive abilities in parents and their 16-year-old children in the Colorado Adoption Project. Cognitive Development, 14, 175-193.

Gayán, J., Smith, S.D., Cherny, S.S., Cardon, L.R., Fulker, D.W., Brower, A.M., Olson, R.K., Pennington, B.F., & DeFries, J.C. (1999). Quantitative-trait locus for specific language and reading deficits on chromosome 6p. American Journal of Human Genetics, 64, 157-164.

Knopik, V.S., & DeFries, J.C., (1999). Etiology of covariation between reading and mathematics performance: a twin study. Twin Research, 2, 226-234.

Pennington, B.F., Filipek, P.A., Lefly, D., Churchwell, J., Kennedy, D.N., Simon, J.H., Filley, C.M., Galaburda, A., Alarcón, M., & DeFries, J.C. (1999). Brain morphometry in reading-disabled twins. Neurology, 53, 723-729.

Schmitz, S., Fulker, D.W., Plomin, R., Zahn-Waxler, C., Emde, R.N., & DeFries, J.C. (1999). Temperament and problem behaviour during early childhood. International Journal of Behavioral Development, 23, 333-355.

Wadsworth, S.J., Fulker, D.W., & DeFries, J.C. (1999). Stability of genetic and environmental influences on reading performance at 7 and 12 years of age in the Colorado Adoption Project. International Journal of Behavioral Development, 23, 319-332.

Alarcón, M., Knopik, V.S., & DeFries, J.C. (2000). Covariation of mathematics achievement and general cognitive ability in twins. Journal of School Psychology, 38, 63-77.

Alarcón, M., Pennington, B.F., Filipek, P.A., DeFries, J.C. (2000). Etiology of neuroanatomical correlates of reading disability. Developmental Neuropsychology, 17, 339-360.

Davis, C.J., Knopik, V.S., Wadsworth, S.J., & DeFries, J.C. (2000). Self-reported reading problems in parents of twins with reading difficulties. Twin Research 3, 88-91.

O’Connor, T.G., Caspi, A., DeFries, & J.C., Plomin, R. (2000). Are associations between parental divorce and children’s adjustment genetically mediated? An adoption study. Developmental Psychology, 6, 429-437.

Pennington, B.F., Filipek, P.A., Lefly, D., Chhabildas, N., Kennedy, D.N., Simon, J.H., Filley, C.M., Galaburda, A, & DeFries, J.C. (2000). A twin MRI study of size variations in the human brain. Journal of Cognitive Neuroscience, 12, 223-232.

Wadsworth, S.J., Knopik, V.S., & DeFries, J.C. (2000). Reading disability in boys and girls: No evidence for a differential genetic etiology. Reading and Writing: An Interdisciplinary Journal, 13, 133-145.

Wadsworth, S.J., Olson, R.K., Pennington, B.F., & DeFries, J.C. (2000). Differential genetic etiology of reading disability as a function of IQ. Journal of Learning Disabilities, 33, 192-199.

Willcutt, E.G., Pennington, B.F., & DeFries J.C. (2000). Etiology of inattention and hyperactivity/impulsivity in a community sample of twins with learning difficulties. Journal of Abnormal Child Psychology, 28, 149-159.

Willcutt, E.G., Pennington, B.F., & DeFries J.C. (2000). Twin study of the etiology of comorbidity between reading disability and attention-deficit/hyperactivity disorder. American Journal of Medical Genetics (Neuropsychiatric Genetics), 96, 293-301.

Compton, D.L., DeFries, J.C., Olson, R.K. (2001). Are RAN- and phonological awareness-deficits additive in children with reading disbilities? Dyslexia, 7, 125-149.
Davis, C.J., Gayán, J., Knopik, V.S., Smith, S.D., Cardon, L.R., Pennington, B.F., Olson, R.K., & DeFries, J.C. (2001). Etiology of reading difficulties and rapid naming: The Colorado Twin Study of Reading Disability. Behavior Genetic, 31, 625-635.

Davis, C.J., Knopik, V.S., Olson, R.K., Wadsworth, S.J., DeFries, J.C. (2001). Genetic and environmental influences on rapid naming and reading ability: A twin study. Annals of Dyslexia, 51, 231-247.

Turri, M.G., Datta, S.R., DeFries, J.C., Henderson, N.D., & Flint, J. (2001). QTL analysis identifies multiple behavioral dimensions in ethological tests of anxiety in laboratory mice. Current Biology, 11, 725-734.

Turri, M.G., Henderson, N.D., DeFries, J.C., & Flint, J. (2001). Quantitative trait locus mapping in laboratory mice derived from a replicated selection experiment for open-field activity. Genetics, 158, 1217-1226.

Wadsworth, S.J., Corley, R.P., Hewitt, J.K., & DeFries, J.C. (2001). Stability of genetic and environmental influences on reading performance at 7, 12, and 16 years of age in the Colorado Adoption Project. Behavior Genetics, 31, 353-359.

Compton, D.L., Olson, R.K., DeFries, J.C., & Pennington, B.F. (2002). Comparing the relationships among two different versions of alphanumeric rapid automatized naming and word level reading skills. Scientific Studies of Reading, 6(4), 343-368.

Fisher, S.E., & DeFries, J.C. (2002). Developmental Dyslexia: Genetic Dissection of a complex cognitive trait. Nature Reviews Neuroscience, 3, 767-780.

Fisher, S.E., Francks, C., Marlow, A.J., MacPhie, L., Newbery, D.F., Cardon, L.R., Ishikawa-Brush, Y., Richardson, A.J., Talcott, J.B., Gayán, J., Olson, R.K., Pennington, B.F., Smith, S.D., DeFries, J.C., Stein, J.F., & Monaco, A.P. (2002). Independent genome-wide scans identify a chromosome 18 quantitative-trait locus influencing dyslexia. Nature Genetics, 30, 86-91.

Francks, C., Fisher, S.E., Olson, R.K., Pennington, B.F., Smith, S.D., DeFries, J.C., & Monaco, A.P. (2002). Fine mapping of the chromosome 2p12-16 dyslexia susceptibility locus: quantitative association analysis and positional candidate genes SEMA4F and OTX1. Psychiatric Genetics, 12, 35-41.

Kaplan, D.E., Gayán, J., Ahn, J., Won, T.-W., Pauls, D., Olson, R.K., & DeFries, J.C. (2002). Evidence for linkage and association with reading disability, on 6p21.3-22. American Journal of Human Genetics, 70, 1287-1298.

Knopik, V.S., Smith S.D., Cardon, L., Pennington, B., Gayán, J., Olson, R.K., DeFries, J.C. (2002). Differential genetic etiology of reading component processes as a function of IQ. Behavior Genetics, 32, 181-198.

Wadsworth, S.J., Corley, R.P., Hewitt, J.K., Plomin, R., & DeFries, J.C. (2002). Parent–offspring resemblance for reading performance at 7, 12 and 16 years of age in the Colorado Adoption Project. Journal of Child Psychology and Psychiatry, 43(6), 769-774.

Willcutt, E,G., Pennington, B.F., Smith, S.D., Cardon, L.R., Gayán, J., Knopik, V.S., Olson, R.K., & DeFries, J.C. (2002). Quantitative trait locus for reading disability on chromosome 6p is pleiotropic for attention-deficit/hyperactivity disorder. American Journal of Human Genetics (Neuropsychiatric Genetics), 114, 260-268.

Young, S.E., Smolen A., Corley, R.P., Krauter, K.S., DeFries, J.C., Crowley, T.J., & Hewitt, J.K. (2002). Dopamine transporter polymorphism associated with externalizing behavior problems in children. American Journal of Human Genetics (Neuropsychiatric Genetics), 114, 144-149.

Bishop, E.G., Cherny, S.S., Corley, R., DeFries, J.C., & Hewitt, J.K. (2003). Developmental genetic analysis of general cognitive ability from 1 to 12 years in a sample of adoptees, biological siblings, and twins. Intelligence, 31, 31-49.

O’Connor, T.G., Caspi, A., DeFries, J.C., & Plomin, R. (2003). Genotype–environment interaction in children’s adjustment to parental separation. Journal of Child Psychology and Psychiatry, 44(6), 849-856.

Deffenbacher, K.E., Kenyon, J.B., Hoover, D.M., Olson, R.K., Pennington, B.F., DeFries, J.C., & Smith, S.D. (2004). Refinement of the 6p21.3 quantitative trait locus influencing dyslexia: Linkage and association analyses. Human Genetics, 115, 128-138.

Flint, J., DeFries, J.C., & Henderson, N.D. (2004). Little epistasis for anxiety-related measures in the DeFries strains of laboratory mice. Mammalian Genome: Genes and Phenotypes, 15, 77-82.

Francks, C., Paracchini, S., Smith, S.D., Richarson, A.J., Scerri, T.S., Cardon, L.R., Marlow, A.J., MacPhie, L., Walter, J., Pennington., B.F., Fisher, S.E., Olson, R.K., DeFries, J.C., Stein, J.F., Monaco, A.P. (2004). A 77-kilobase region of chromosome 6p22.2 is associated with dyslexia in families from the United Kingdom and from the United States. American Journal of Human Genetics, 75, 1046-1058.

Henderson, N.D., Turri, M.G., DeFries, J.C., & Flint, J. (2004). QTL analysis of multiple behavioral measures of anxiety in mice. Behavior Genetics, 34(3), 267-293.

Hulslander, J., Talcott, J., Witton, C., DeFries, J., Pennington, B., Wadsworth, S., Willcutt, E., Olson, R. (2004). Sensory processing, reading, IQ, and attention. Journal of Experimental Child Psychology, 88, 274-295.

Tiu, R.D., Wadsworth, S.J., Olson, R.K., & DeFries, J.C. (2004). Causal models of reading disability: A twin study. Twin Research, 7(3), 275-283.

Turri, M.G., DeFries, J.C., Henderson, N.D., & Flint, J. (2004). Multivariate analysis of quantitative trait loci influencing variation in anxiety-related behavior in laboratory mice. Mammalian Genome: From Genotype to Phenotype, 15, 69-76.

Williams, R.W., Bennett, B., Lu, L., Gu, J., DeFries, J.C., Carosone-Link, P.J., Rikke, B.A., Belknap, J.K., Johnson, T.E. (2004). Genetic structure of the LXS panel of recombinant inbred mouse strains: A powerful resource for complex trait analysis. Mammalian Genome, 15, 637-647.

Byrne, B., Wadsworth, S., Corley, R., Samuelsson, S., Quain, P., DeFries, J.C., Willcutt, E., & Olson, R.K. (2005). Longitudinal twin study of early literacy development: Preschool and kindergarten phases. Scientific Studies of Reading, 9(3), 219-235.

Gayán, J., Willcutt, E.G., Fisher, S.E., Francks, C., Cardon, L.R., Olson, R.K., Pennington, B.F., Smith, S.D., Monaco, A.P., and DeFries, J.C. (2005). Bivariate linkage scan for reading disability and attention-deficit/hyperativity disorder localizes pleiotropic loci. Journal of Child Psychology and Psychiatry, 46(10), 1045-1056.

Meng, H., Hager, K., Held, M., Page, G.P., Olson, R.K., Pennington, B.F., DeFries, J.C., Smith, S.D., Gruen, J.R. (2005). TDT-association analysis of EKN1 and dyslexia in a Colorado twin cohort. Human Genetics, 118, 87-90.

Meng, H., Smith, S.D., Hager, K., Held, M., Liu, J., Olson, R.K., Pennington, B.F., DeFries, J.C., Gelernter, J., O'Reilly-Pol, T., Somlo, S., Skudlarski, P., Shaywitz, S.E., Shaywitz, B.A., Marchione, K., Wang, Y., Paramasivam, M., LoTurco, J.J., Page, G.P., & Gruen J.R. (2005). DCDC2 is associated with reading disability and modulates neuronal development in the brain. Proceedings of the National Academy of Sciences, 102(47), 17053-17058.

Samuelsson, S., Byrne, B., Quain, P., Wadsworth, S., Corley, R., DeFries, J.C., Willcutt, E., & Olson, R. (2005). Environmental and genetic influences on prereading skills in Australia, Scandinavia, and the United States. Journal of Educational Psychology, 97(4), 705-722.

Wadsworth, S.J., & DeFries, J.C. (2005). Genetic etiology of reading difficulties in boys and girls. Twin Research and Human Genetics, 8(6), 594-601.

Bricker, J.B., Stallings, M.C., Corley, R.P., Wadsworth, S.J., Bryan, A., Timberlake, D.S., Hewitt, J.K., Caspi, A., Hofer, S.M., Rhea, S.A., DeFries, J.C. (2006).  Genetic and environmental influences on age at sexual initiation in the Colorado Adoption Project.  Behavior Genetics, 36, 820-832.

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.

Friedman, N.P., Miyake, A., Corley, R.P., Young, S.E., DeFries, J.C., & Hewitt, J.K. (2006).  Not all executive functions are related to intelligence.  Psychological Science, 17(2), 172-179.

Hawke, J.L., Wadsworth, S.J., & DeFries, J.C. (2006).  Genetic influences on reading difficulties in boys and girls: The Colorado Twin Study.  Dyslexia, 12, 21-29.

Keenan, J.M., Betjemann, R.S., Wadsworth, S.J., DeFries, J.C., & Olson, R.K. (2006).  Genetic and environmental influences on reading and listening comprehension.  Journal of Research in Reading, 29(1), 75-91.

Shanahan, M.A., Pennington, B.F., Yerys, B.E., Scott, A., Boada, R., Willcutt, E.G., Olson, R.K., & DeFries, J.C. (2006).  Processing speed deficits in attention deficit/hyperactivity disorder and reading disability.  Journal of Abnormal Child Psychology, 34, 585-602.

Astrom, R.L., Wadsworth, S.J., & DeFries, J.C. (2007).  Etiology of the stability of reading difficulties: The Longitudinal Twin Study of Reading Disabilities.  Twin Research and Human Genetics, 10(3), 434-439.

Bidwell, L.C., Willcutt, E.G., DeFries, J.C., Pennington, B.F. (2007). Testing for neuropsychological endophenotypes in siblings discordant for attention-deficit/hyperactivity disorder. Biological Psychiatry, 62, 991-998.

Byrne, B., Samuelsson, S., Wadsworth, S., Hulslander, J., Corley, R., DeFries, J.C., Quain, P., Willcutt, E.G., & Olson, R.K. (2007).  Longitudinal twin study of early literacy development: Preschool through  grade 1.  Reading and Writing, 20, 77-102.

Friend, A., DeFries, J.C., Wadsworth, S.J., & Olson, R.K. (2007).  Genetic and environmental influences on word recognition and spelling deficits as a function of age.  Behavior Genetics, 37, 477-486.

Hawke, J.L., Wadsworth, S.J., Olson, R.K., & DeFries, J.C. (2007).  Etiology of reading difficulties as a function of gender and severity.  Reading and Writing, 20, 13-25.

Samuelsson, S., Olson, R., Wadsworth, S., Corley, R., DeFries, J.C., Willcutt, E., Hulslander, J., 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, 51-75.

Wadsworth, S.J., DeFries, J.C., Olson, R.K., & Willcutt, E.G. (2007). Colorado Longitudinal Twin Study of Reading Disability. Annals of Dyslexia, 57, 139-160.

Willcutt, E.G., Betjemann, R.S., Pennington, B.F., Olson, R.K., DeFries, J.C., & Wadsworth, S.J. (2007). Longitudinal Study of Reading Disability and Attention Deficit/Hyperactivity Disorder: Implications for education. Mind, Brain and Education, 1(4), 181-192.

Willcutt, E.G., Betjemann, R.S., Wadsworth, S.J., Samuelsson, S., Corley, R., DeFries, J.C., Byrne, B., Pennington, B.F., Olson, R.K. (2007).  Preschool twin study of the relation between attention-deficit/hyperactivity disorder and prereading skills.  Reading and Writing, 20, 103-125.

Willcutt, E.G., Pennington, B.F., Olson, R.K., & DeFries, J.C. (2007). Understanding cormorbidity: A twin study of reading disability and attention-deficit/hyperactivity disorder. American Journal of Medical Genetics Part B (Neuropsychiatric Genetics), 114B, 709-714.

Betjemann, R.S., Willcutt, E.G., Olson, R.K., Keenan, J.M., DeFries, J.C., Wadsworth, S.J. (2008).  Word reading and reading comprehension: Stability, overlap and independence.  Reading and Writing, 21, 539-558.

Byrne, B., Coventry, W.L., Olson, R.K., Hulslander, J., Wadsworth, S., DeFries, J.C., Corley, R.,  Willcutt, E.G., & Samuelsson, S. (2008).  A behaviour-genetic analysis of orthographic learning, spelling and decoding. Journal of Research in Reading, 31(1), 8-21. 

Friedman, N.P., Miyake, A., Young, S.E., DeFries, J.C., Corley, R.P., & Hewitt, J.K. (2008).  Individual differences in executive functions are almost entirely genetic in origin. Journal of Experimental Psychology: General, 137(2), 201-225.

Friend, A., DeFries, J.C., & Olson, R.K. (2008).  Parental education moderates genetic influences on reading disability.  Psychological Science, 19(11), 1124-1130.

Hawke, J.L., Stallings, M.C., Wadsworth, S.J., & DeFries, J.C. (2008).  DeFries-Fulker and Pearson-Aitken model-fitting analyses of reading performance data from selected and unselected twin pairs.  Behavior Genetics, 38, 101-107.

Rhee, S.H., Willcutt, E.G., Hartman, C.A., Pennington, B.F., DeFries, J.C. (2008).  Test of alternative hypotheses explaining the comorbidity between Attention-Deficit/Hyperactivity Disorder and Conduct Disorder. Journal of Abnormal Child Psychology, 36, 29-40.

Samuelsson, S., Byrne, B., Olson, R.K., Hulslander, J., Wadsworth, S., Corley, R., Willcutt, E.G., 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, 289-295.

Brant, A.M., Haberstick, B.C., Corley, R.P., Wadsworth, S.J., DeFries, J.C., & Hewitt, J.K. (2009). The developmental etiology of high IQ. Behavior Genetics, 39, 393-405.

Byrne, B., Coventry, W.L., Olson, R.K., Samuelsson, S., Corley, R., Willcutt, E.G., Wadsworth, S. & DeFries, J.C. (2009).  Genetic and environmental influences on aspects of literacy and language in early childhood: Continuity and change from preschool to Grade 2. Journal of Neurolinguistics, 22, 219-236.

Friend, A., DeFries, J.C., Olson, R.K., Pennington, B., Harlaar, N., Byrne, B., Samuelsson, S., Willcutt, E.G., Wadsworth, S.J., Corley, R., & Keenan, J.M. (2009).  Heritability of high reading ability and its interaction with parental education.  Behavior Genetics, 39, 427-436.

Hawke, J.L., Olson, R.K., Willcutt, E.G., Wadsworth, S.J., & DeFries, J.C. (2009).  Gender ratios for reading difficulties.  Dyslexia, 15, 239-242.

Pennington, B.F., McGrath, L.M., Rosenberg, J., Barnard, H., Smith, S.D., Willcutt, E.G., Friend, A., DeFries, J.C., & Olson, R.K. (2009).  Gene X environment interactions in Reading Disability and Attention-Deficit/Hyperactivity Disorder.  Developmental Psychology, 45(1), 77-89.

Betjemann, R.S., Johnson, E.P., Barnard, H., Boada, R., Filley, C.M., Filipek, P.A., Willcutt, E.G., DeFries, J.C., Pennington, B.F. (2010).  Genetic covariation between brain volumes and IQ, reading performance, and processing speed. Behavior Genetics, 40, 135-145.

DeFries, J.C. (2010).  Haseman and Elston sib-pair linkage analysis: A brief historical note. Behavior Genetics, 40, 1-2.

Haworth, C.M.A., Wright, M.J., Luciano, M., Martin, N.G., de Geus, E.J.C., van Beijsterveldt, C.E.M., Bartels, M., Posthuma, D., Boomsma, D.I., Davis, O.S.P., Kovas, Y., Corley, R.P., DeFries, J.C., Hewitt, J.K., Olson, R.K., Rhea, S.-A., Wadsworth, S.J., Iacono, W.G., McGue, M., Thompson, L.A., Hart, S.A., Petrill, S.A., Lubinski, D., & Plomin, R. (2010).  The heritability of general cognitive ability increases linearly from childhood to young adulthood.  Molecular Psychiatry, 15, 1112-1120.

Scerri, T.S., Paracchini, S., Morris, A., MacPhie, I. L., Talcott, J., Stein, J., Smith, S.D., Pennington, B.F., Olson, R.K., DeFries, J.C., Monaco, A.P. (2010). Identification of candidate  genes for dyslexia susceptibility on chromosome 18. PLoS ONE, 5:1-8. e13712.

McGrath, L.M., Pennington, B.F., Shanahan, M.A., Santerre-Lemmon, L.E., Barnard, H.D., Willcutt, E.G., Defries, J.C., Olson, R.K. (2010). A multiple deficit model of reading disability and attention-deficit/hyperactivity disorder: searching for shared cognitive deficits. J Child Psychol Psychiatry, Dec. 3.

Willcutt, E.G., Betjemann, R.S., McGrath, L.M., Chhabildas, N.A., Olson, R.K., DeFries, J.C., Pennington, B.F. (2010). Etiology and neuropsychology of comorbidity between RD and ADHD: the case for multiple-deficit models. Cortex, 46(10): 1345-1361.

Willcutt, E.G., Pennington, B.F., Duncan, L., Smith, S.D., Keenan, J.M., Wadsworth, S., DeFries, J.C., Olson, R.K. (2010). Understanding the complex etiologies of developmental disorders: behavioral and molecular genetic approaches. J Dev Behav Pediatr, 31(7): 533-544.

Wadsworth, S.J., Olson, R.K., DeFries, J.C. (2010). Differential genetic etiology of reading difficulties as a function of IQ: an update. Behavior Genetics, 40(6): 751-758.

Smith, S.D., Grigorenko, E., Willcutt, E.G., Pennington, B.F., Olson, R.K., DeFries, J.C. (2010). Etiologies and Molecular Mechanisms of Communication Disorders. Journal of Developmental Behavioral Pediatrics, 31(7): 555-563.

Olson, R.K., Keenan, J.M., Byrne, B., Samuelsson, S., Coventry, W.L., Corley, R., Wadsworth, S.J., Willcutt, E.G., DeFries, J.C., Pennington, B.F., Hulslander, J. (2011). Genetic and Environmental Influences on Vocabulary and Reading Development. Scientific Studies of Reading, 15(1), 26-46.

Bidwell, L.C., Willcutt, E.G., McQueen, M.B., DeFries, J.C., Olson, R.K., Smith, S.D., Pennington, B.F. (2011). A Family Based Association Study of DRD4, DAT1, and 5HTT and Continuous Traits of Attention-Deficit Hyperactivity Disorder. Behavior Genetics, 41:165-174.

Betjemann, R.S., Keenan, J.M., Olson, R.K., DeFries, J.C. (2011). Choice of Reading Comprehension Test Influences the Outcomes of Genetic Analyses. Scientific Studies of Reading, 15:4, 363-382.

McGrath, L.M., Pennington, B.F., Shanahan, M.A., Santerre-Lemmon, L.E., Barnard, H.D., Willcutt, E.G., DeFries, J.C., Olson, R.K. (2011). A Multiple Deficit Model of Reading Disability and Attention-Deficit/Hyperactivity Disorder: Searching for Shared Cognitive Deficits. The Journal of Child Psychology and Psychiatry, 52(5), 547-557.

Astrom, R.L., Wadsworth, S.J., Olson, R.K., Willcutt, E.G., DeFries, J.C. (2011). DeFries-Fulker Analysis of Longitudinal Reading Performance Data from Twin Pairs Ascertained for Reading Difficulties and from Their Nontwin Siblings. Behavior Genetics, 41:660-667.

Willcutt, E.G., Boada, R., Riddle, M.W., Chhabildas, N., DeFries, J.C., Pennington, B.F. (2011). Colorado Learning Difficulties Questionnaire: Validation of a Parent-Report Screening Measure. Psychological Assessment, 23(3), 778-791.

Nilsson, R., Rhee, S.H., Corley, R.P., Rhea, SA., Wadsworth, S.J., DeFries, J.C. (2011). Conduct Problems in Adopted and Non-Adopted Adolescents and Adoption Satisfaction as a Protective Factor. Adoption Quarterly, 14(3), 181-198.

Olson, R.K., Hulslander, J., Christopher, M., Keenan, J.M., Wadsworth, S.J., Willcutt, E.G., Pennington, B.F., & DeFries, J.C. (2011). Genetic and environmental influences on writing and their relations to language and reading. Annals of Dyslexia. NIHMSID #287212. DOI: 10.1007/s11881-011-0055-z Online first, August 13, 2011.

Astrom, R.L., Wadsworth, S.J., Olson, R.K., Willcutt, E.G., & DeFries, J.C. (2012). Genetic and environmental etiologies of reading difficulties: DeFries–Fulker analysis of reading performance data from twin pairs and their non-twin siblings. Learning and Individual Differences, 22, 365-369.

Christopher, M.E., Miyake, A., Keenan, J.M., Pennington, B., DeFries, J.C., Wadsworth, S.J., Willcutt, E., and Olson, R.K. (2012.) Predicting word reading and comprehension with executive function and speed measures across development: A latent variable analysis. Journal of Experimental Psychology: General, 141(3), 470-488.

Wadsworth, S.J., Olson, R.K., Willcutt, E.G., & DeFries, J.C. (2012). Multiple Regression Analysis of Reading Performance Data from Twin Pairs with Reading Difficulties and Nontwin Siblings: The Augmented Model. Twin Research and Human Genetics, 15(1), 116-119.

Olson, R.K., Hulslander, J., Christopher, M., Keenan, J.M., Wadsworth, S.J., Willcutt, E.G., Pennington, B.F., DeFries, J.C. (2013). Genetic and environmental influences on writing and their relations to language and reading. Annals of Dyslexia, 63: 25-43.

Fujisawa, K.K., Wadsworth, S.J., Kakihana, S., Olson, R.K., DeFries, J.C., Byrne, B., Ando, J. (2013). A multivariate twin study of early literacy in Japanese kana. Learning and Individual Differences, 24, 160-167.

Rhea, S.A., Bricker, J.B., Corley, R.P., DeFries, J.C., Wadsworth, S.J. (2013). Design, utility, and history of the Colorado Adoption Project: Examples involving adjustment interactions. Adoption Quarterly, 16:1, 17-39.

Christopher, M.E., Hulslander, J., Byrne, B., Samuelsson, S., Keenan, J.M., Pennington, B., DeFries, J.C., Wadsworth, S.J., Willcutt, E., Olson, R.K. (2013). The genetic and environmental etiologies of individual differences in early reading growth in Australia, the United States, and Scandinavia. Journal of Experimental Child Psychology, 115: 453-467.

Trzaskowski, M., Davis O.S.P., DeFries, J.C., Yang, J., Visscher, P.M., Plomin, R. (2013). DNA evidence for strong genome-wide pleiotropy of cognitive and learning abilities. Behavior Genetics, 43: 267-273.

Brant, A.M., Munakata, Y., Boomsma, D.I., DeFries, J.C., Haworth, C.M.A., Keller, M.C., Martin, N.G., McGue, M., Petrill, S.A., Plomin, R., Wadsworth, S.J., Wright, M.J., Hewitt, J.K. (2013). The nature and nurture of high IQ: An extended sensitive period for intellectual development. Psychological Science, 24:8, 1487-1495.

Willcutt, E.G., Petrill, S.A., Wu, S., Boada, R., DeFries, J.C., Olson, R.K., Pennington, B.F. (2013). Comorbidity between reading disability and math disability: Concurrent psychopathology, functional impairment, and neuropsychological functioning. Journal of Learning Disabilities, 46:6, 500-516.

Christopher, M.E., Hulslander, J., Byrne, B., Samuelsson, S., Keenan, J.M., Pennington, B., DeFries, J.C., Wadsworth, S.J., Willcutt, E.G., 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.

Power, R.A., Nagoshi, C., DeFries, J.C., Plomin, R., Wellcome Trust Case Control Consortium 2. (2014). Genome-wide estimates of inbreeding in unrelated individuals and their association with cognitive ability. European Journal of Human Genetics, 22(3), 386-390.

Willcutt, E.G., Chhabildas, N., Kinnear, M., DeFries, J.C., Olson, R.K., Leopold, D.R., Keenan, J.M., Pennington, B.F. (2014). The internal and external validity of sluggish cognitive tempo and its relation with DSM-IV ADHD. Journal of Abnormal Child Psychology, 42, 21-35.

Eicher, J.D., Powers, N.R., Miller, L.L., Mueller, K.L., Mascheretti, S., Marino, C., Willcutt, E.G., DeFries, J.C., Olson, R.K., Smith, S.D., Pennington, B.F., Tomblin, J.B., Ring, S.M., Gruen, J.R. (2014). Characterization of the DYX2 locus on chromosome 6p22 with reading disability, language impairment, and IQ. Human Genetics, 133(7), 869-881.

Gialluisi, A., Newbury, D.F., Wilcutt, E.G., Olson, R.K., DeFries, J.C., Brandler, W.M., Pennington, B.F., Smith, S.D., Scerri, T.S., Simpson, N.H., SLI Consortium, Luciano, M., Evans, D.M., Bates, T.C., Stein, J.F., Talcott, J.B., Monaco, A.P., Paracchini, S., Francks, C., Fisher, S.E. (2014). Genome-wide screening for DNA variants associated with reading and language traits. Genes, Brain and Behavior, 13, 686-701.

Christopher, M.E., Hulslander, J., Byrne, B., Samuelsson, S., Keenan, J.M., Pennington, B., DeFries, J.C., Wadsworth, S.J., Willcutt, E., Olson, R.K. (2015). Genetic and environmental etiologies of the longitudinal relations between prereading skills and reading. Child Development, 86(2), 342-361.

Arnett, A.B., Pennington, B.F., Willcutt, E.G., DeFries, J.C., Olson, R.K. (2015). Sex differences in ADHD symptom severity. The Journal of Child Psychology and Psychiatry, 56(6), 632-639.

Wadsworth, S.J., DeFries, J.C., Willcutt, E.G., Pennington, B.F., Olson, R.K. (2015). The Colorado Longitudinal Twin Study of Reading Difficulties and ADHD: Etiologies of comorbidity and stability. Twin Research and Human Genetics, 5, 1-7.

Plomin, R., DeFries, J.C., Knopik, V.S., Neiderhiser, J.M. (2016). Top 10 Replicated Findings From Behavioral Genetics. Perspectives on Psychological Science, 11(1): 3-23.

Ayorech, Z., Selzam, S., Smith-Woolley, E., Knopik, V.S., Neiderhiser, J.M., DeFries, J.C., Plomin, R. (2016). Publication Trends Over 55 Years of Behavioral Genetic Research. Behavior Genetics, 46(5): 603-607.

Huibregtse, B.M., Corley, R.P., Wadsworth, S.J., Vandever, J.M., DeFries, J.C., Stallings, M.C. (2016). A Longitudinal Adoption Study of Substance Use Behavior in Adolescence. Twin Research and Human Genetics, 19(4): 330-340.

Christopher, M.E., Keenan, J.M., Hulslander, J., DeFries, J.C., Miyake, A., Wadsworth, S.J., Willcutt, E., Pennington, B., Olson, R.K. (2016). The genetic and environmental etiologies of the relations between cognitive skills and components of reading ability. Journal of Experimental Psychology: General, 145(4): 451-466.

Wadsworth, S.J., DeFries, J.C., Willcutt, E.G., Pennington, B.F., Olson, R.K. (2016). Genetic Etiologies of Comorbidity and Stability for Reading Difficulties and ADHD: A Replication Study. Twin Research and Human Genetics, 19(6): 647-651.

Gialluisi, A., Visconti, A., Willcutt, E.G., Smith, S.D., Pennington, B.F., Falchi, M., DeFries, J.C., Olson, R.K., Francks, C., Fisher, S.E. (2016). Investigating the effects of copy number variants on reading and language performance. Journal of Neurodevelopmental Disorders, 8: 17.

Arnett AB, Pennington BF, Peterson RL, Willcutt EG, DeFries JC, Olson RK. Explaining the sex difference in dyslexia. J Child Psychol Psychiatry. 2017 Jun;58(6):719-727.

Selzam S, Dale PS, Wagner RK, DeFries JC, Cederlöf M, O'Reilly PF, Krapohl E, Plomin R. Genome-Wide Polygenic Scores Predict Reading Performance Throughout the School Years. Sci Stud Read. 2017 Jul 4;21(4):334-349

Adams AK, Smith SD, Truong DT, Willcutt EG, Olson RK, DeFries JC, Pennington BF, Gruen JR. Enrichment of putatively damaging rare variants in the DYX2 locus and the reading-related genes CCDC136 and FLNC. Hum Genet. 2017 Nov;136(11-12):1395-1405.

Ricker AA, Corley R, DeFries JC, Wadsworth SJ, Reynolds CA. Examining the influence of perceived stress on developmental change in memory and perceptual speed for adopted and nonadopted individuals. Dev Psychol. 2018 Jan;54(1):138-150.

 

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