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Cognitive Development in Inattentive, Hyperactive, and Aggressive Children: Two- to Five-year Follow-up
Cognitive Development in Inattentive, Hyperactive, and Aggressive Children: Two- to Five-Year Follow-up HARRIS S. GOLDSTEIN, M.D.. D.MED.Sc. Abstract . . One thi~~ of children assessed when they were ages 6-11 were reassessed at ages 12-17. The relationship 01 the cogruuve development of these youths to their categorization at ages 6-11 along the dimensions of aucnuvcness, hyperact ivity. and aggressivity was examined. Control for initial level of cognitive performance was I~corporated with controls for famil y context. Results demonstrated a continuing effect of below average attentiveness at the younger age on the youth's cognitive development as defined by WISC Vocabulary and Block Design sUh~e~ts and WRA: Read.ing a.nd Arith"?etic su~t~sts adm inistered at the latter age. Neither hyperactivity nor aggrcssivuy was associated With differences In cogruuvc development. J. Amer. Acad. Child Adol. Psychiat.• 1987, 26. 2:219-221 . Key Words: attention. hyperactivity, cognitive development.
Method
In a report on the impact oflow attentiveness, hyperactivity, and aggressivity on cognitive development in a national probability sample of 6- through II-year-old children. the child attribute that predicted poor performance on intellectual and academic measures was lower than average attentiveness (Goldstein. 19H7). The critical question that follows is how persistent is this effect of low attentiveness on cognitive development. In New Zealand in a 2-year follow-up at age 9 of hyperactive. hyperactive-aggressive. and aggressive only children, McGee ct al. (1984) demonstrated lags in reading and spelling in the hyperactive children but not in those d isplaying aggressive behavior only. Gillberg et al. (1983), in Sweden, described reading, writing, and spelling lags in a 3-year follow-up at age 10 of minimally brain damaged children (defined as those with attention deficits plus motor and/or perception dysfunction) but not for those children with attention deficit disorder. Although both studies were carefully des igned to control for selection biases and social class . in neither was the baseline achievement level controlled. In the New Zealand study, given the degree of lag at the younger age, it was unclear whether the lag at follow-up was in addition to that described at age 7 or whether the lag was stable and still evident at age 9. Similarly, in the Gillberg report the lack of control for initial performance leaves open the question of whether the children with attention difficulties were developing at the same rate or were catching up at the time of the follow-up, In the stud y reported here, one third of the children in the orig inal national sample of 6- through II-year-olds were retested on the same cognitive measures between the ages of 12 and 17. 2 to 5 years after the initial testing. In the analysis of the data, the initial performance is controlled. as is famil v context. Thus the present stud y examines the elTect of the attributes of low attentiveness, hyperactivity. and aggressivity observed between 6 and II years of age on the youths' cognitive performance when the y are 12-17 years old,
Sample The data are from Cycle II (NCHS, 1967) and Cycle III (NCHS, 1969) of the Health Examination Surveys conducted by the National Center for Health Statistics of the U. S, Public Health Service. The sample design for both cycles used the same multistage probability sample of clustered households to provide representative samples of the 6- to II-year-old (Cycle II) and the 12- to 17-year-old (Cycle III) noninstitutionalized population of the United States. Because the same household clusters were used in Cycle III as in Cycle II, a substantial proportion of youths examined in Cycle II were reexamined in Cycle III. Two factors, however. age and family mobility. limited the number of reexamined children, More than one third of the children who were aged 6-11 during Cycle II were not yet age 12 at the time of Cycle III and were therefore not eligible for inclusion . Furthermore. in the interval between examinations, a substantial number of families moved from the household clusters being sampled and these youths were. consequently, not eligible for reexamination . Although those excluded because of age would not bias the sample in any way. the exclusion of children whose families moved can Introduce some socioeconomic bias, Socioeconomic status. however. was carefully controlled in this study, Nonetheless. the population reexamined. although substantial in number. is not as representative of the national cohort as is the total sample of either cycle . These reexamined youths still constitute the largest and most representative United States sample available for analysis to date. In sum, of the 7119 children examined in the Cycle II Survey. approximately one third were reexamined in Cycle III. permitting a comparison of their status at dilTerent ages. The pre sent study uses the data of the white youths because the yo uths of other races were too few in number for analyses across the many categories of behavior of the independent variable. In addition. only youths whose estimated IQ was 70 or greater at the Cycle II examination were included. The interval between the two examinations varied from 28 months 1053 months. with a mean interval of42.16 months. a median of 43 months. and a mode of 48 months.
Received Oct. 15. I'NU; revised Jan. Ii. IWlb; accepted Feb. 17,
tvs«
Dr. Goldstein is Associate Profrssor ofPsvchiutry at the Universit v o( Medicine and Dentistry (II' NCII' Jersey . Rutgers Medical Schuol, Pi .H·lI/(JI\·lIl', Nell' Jcrscv.
COXll it ivc Measures
Reqllesis.!ilr reprint .\--to Dr. Goldstein, Dept . ofPsvchiatrv. UM DNJ. RIIl!:er,1 Medical School, Piscutawav, NJ 08854. ' 0890-8567/87/2602-0219$02.00/0 (e) 1987 by the American Academy of Child and Adolescent Psychiatry.
As previously described. two subtests of the WISe, Vocabulary and Block Design. and two subtests of the WRAT, Reading and Arithmetic. were administered to evaluate intel~1 !1
220
GOLDSTEIN
lcctual development and school achievement. The subtest scores were standardized and are reported as T scores with a mean of 50 and a standard deviation of 10 (Roberts. 1971). An IQ estimate. the Intellectual Index. was computed by summing the Vocabulary and Block Design scores and setting the mean to 100 and S.D . to 15. An Achievement Index was sim ilarly computed by summing the Reading and Arithmetic subtc sts, setting the mean to 100 and S.D . to 15. Family Background (Contro! J'ariahles)
Three family characteristics known to influence cognitive development were controlled. These characteristics. parental edu cation. family income. and number of siblings. were combined into two covariates. The two family background covariates were parental education and income per sibling in household.
Classroom Behavior (Behavior Group Factor) The three areas of classroom behavior assessed by the school when the child was 6 to I I years old that are relevant to this study were attenti veness. acti vity level. and aggressivity (Robert s and Baird . 1972). A child described as lower than average in attentiveness was defined as low attentive: if the child was constantly on the move he was considered hyperactive; and if the child frequently required discipline for aggressive behavior. he was considered an aggressive child . These three attributes in combination yielded eight categories of behavior. Because of an insufficient number of children in one category (low attentive plus aggressive) at follow-up. seven categories were used : (a) low attentive; (b) hyperactive: (c) aggressive: (d) low attenti ve plus hyperactive; (e) hyperactive plus aggressive: (f) low attenti ve plus hyperacti ve plus aggressive: and (g) comparison . i.e.. children who were neither low attentive nor hyperactive nor aggressive. Data Analysis The statistical analysis used a one-way analysis of covariance (ANCOVA) with Behavior Group being the independent factor . The covariatcs were (a) the youth's score on the cognitive test during the previous survey (Cycle II). (b) the average parental education. and (c) the family income per sibling at the time of the follow-up . The statistics were computed using the General Linear Model procedure for unbalan ced designs of the Statistical Anal ysis System (SAS. 1982). The F tests usc. for the mean model var iance . the variance contributed to the model when the factor in question is included after the covariates are entered into the equation . The y are. therefore. tests of significance of the independent contribution of the factor to the variance of the outcome measures. When the F test proved significant. post hoc I tests were used to determine which means of the " pro blem" groups d iffered significantly from the comparison group. Given the number of comparisons. an alpha of 0.0 I was used for the I tests. Results
intelligence Tests As can be seen in Table I. the partially adjusted means show greater dispersion than the fully adjusted means between
TABLE I. Percentages I!I' Youths with Lilli' Attentiveness, lIY[Jl'fClCI;I';ly .
and AXX' l'.\·s; I'; I.I'
- - - - --
Percentage (N= 1616) -- .. _ _ . . _ --
Behavior Group Co m pa riso n Low att entive H yperact ive Aggressive Low attentive/hyperactive Hyperacti ve/aggressive Lowattenti ve/h yperactive/aggressive
77.16 14.66 0.68 1.55 2.60 0.68 2.66
the behavior groups. Even though the introduction of the previous test scores as a covariate reduces substantially the variance attributable to the Behavior Group factor, the factor remains significant for Vocabulary, F(6,1615) = 3.05; p = 0.0057; Block Design. F(6,1615) = 2.49: p = 0.0210: and Intellectual Index. F(6,1615) = 3.56: p = 0.0017 . The post hoc I tests demonstrated that significant differences resided between the comparison group and the low attentive group for the three measures (Table 2).
..tchievement Tests The ANCOV As were significant for the Reading, F(6,1615) = 4.61 : p = 0.0001 and Arithmetic. F(6,1615) = 10.05 : p = 0.000 I subtests and for the Achievement Index. F(6, 1615) = 8.16: P = 0.000 I. The post hoc I tests on the adjusted means
revealed that the three low attentive groups-low attentive. low attentive and hyperactive. and low attentive, hyperactive, and aggressive-were significantly different from the comparison group (T able 3). Because at ages 6-11. boys in the aggressive-only group showed lower achievement scores than the comparison group, an additional analysis of the male youths was made. The ANCOVA and post hoc I tests did not differ from values reported for boys and girls combined. The aggressive-only group mean for male youths was not significantly different from the comparison group mean. Discussion The fact that the low attentive group was significantly behind the comparison group. even with the initial cognitive performances controlled. points to the continuing impact of att ent ional problems on development into the adolescent years. an effect that goes beyond any initial disparity in cognitive development. Neither hyperactivity nor aggressivity playa significant role in this aspect of the child's development. Several explanations seem plausible for the worsening performance of the low attentive children. First , the low attentive behavior is likely to have continued (although in the absence of a follow-up assessment. th is can only be surmised) and made the acquisition of school-related knowledge and skills difficult. Second. a lag in earl y skill development and knowledge makes increasingly difficult the acquisition of more advanced skills. Thus failure to acquire average reading ability at age 7 will make acquiring the average vocabulary at age 10 more difficult. Additionally. there is the labeling of the child as a "poor learner" and the common practice of then tracking the child in a slow learner group. These actions may both
221
FOLLOW-UP OF INATTENTIVE CHILDREN TABLE 2. Adjusted" and Partially Adjusted" Means and SE. (If Intelligence Measures
~--.-_._-,-_.
IQ Index
Vocabulary
Block Design
N
Behavior Group
Adjusted
---------
Comparison
Mean (S.E.) Mean (S.E.) Mean (S.E.) Mean (S.E.) Mean (S.E.) Mean (S.E.) Mean (S.E.)
Low attentive Hyperactive Aggressive Low attentive/hyperactive Hyperacti velaggressi vc Low attentive/hyperactive/ aggressive
1247 237 II 25 42 II 43
Partial__
Adjusted
(105.76)
52.79 (0.17) 51.29' (0.39) 52.28 ( 1.79) 52.96 (1.88) 50.78 (0.92) 51.74 ( 1.78) 51.05 (0.91)
- - - _ . _ ~ - - - _ .
104.89 (0.24) 102.60' (0.56) 103.44 (2.58) 105.79 (1.71 ) 102.76 ( 1.32) 100.97 (2.57) 101.97 (l.3I)
(99.69) ( 103.95) (104.66) (98.23) ( 102.54) (97.28) ..
_
-
Partial
Adjusted
Partial
53.02 (0.21) 51.50" (0.47) 51.51 (2.18) 53.91 ( 1.45) 51.95 ( 1.12) 49.98 (2.18) 50.69 (1.11 )
(53.37)
. _--~~-
-----------~-
----
_..
(53.33) (49.51) (54.28) (52.18) (47.47) (53.13) (47.89)
(50.30) (50.20) (53.54) (50.66) (50.17) (49.01)
Adjusted for all covariates. " Adjusted for parental education and income but not for previous cognitive test scores. 'I' < 0.001. d I' < 0.01. u
TABLE 3. Adjusted" and Partially Adjusted" Means and SE. ofAchievement Measures ---_._--------
----
----
---
---,-~--
---------~----------~---------
Achievement Index Behavior Group -------
-
N
------------------
Adjusted
Partial
104.54 (0.22) 101.10' (0.52) 105.64 (2.35) 104.48 ( 1.56) 100.83" (1.21 ) 103.24 (2.35) 100.65" ( 1.20)
(105.90)
------------
Comparison
Mean (S.E.) Mean (S.E.) Mean (S.E.) Mean (S.E.) Mean (S.E.) Mean (S.E.) Mean (S.E.)
Low attentive Hyperactive Aggressive Low attentive/hyperactive Hyperacti ve] aggressi vc Low attentive/hyperactive/ aggressive ------
--
1247 237 II 25 42 II
43
(96.44) (105.83) ( 103.48) (95.05) (101.36) (93.41)
Reading -
Arithmetic
---------------
-------------------
Adjusted
Partial
Adjusted
Partial
52.76 (0.14) 51.22' (0.33) 52.95 ( 1.50) 53.57 ( 1.00) 51.20 (0.77) 51.90 (1.50) 50.58" (0.76)
(53.63)
52.97 (0.20) 49.57' ( 1.07) 5400 (2.09) 52.08 ( 1.39) 49.17" (1.07) 52.12 (2.09) 49.43" (1.07)
(53.62)
----------
(48.38) (53.87) (52.68) (46.91) (50.49) (45.94)
(47.24) (53.50) (51.65) (47.03) (51.11 ) (46.00) ---"---
" Adjusted for all co variates. " Adjusted for parental education and income but not for previous cognitive test scores. 'I' < 0.0001. "I' < 0.001. ,.I' < 0.0 I. discourage a child from putting forth the requisite effort and limit the opportunity to learn at an average or accelerated pace because of the curricular limitations of the slow learner group. Finally, because the low attentive children undoubtedly are a heterogenous group including children with depression and anxiety disorders. the untreated primary disorder may increasingly reduce the ability for focused attention. References Gillberg, I. C; Gillberg, C & Rasmussen. F. (1983). Three-year follow-up at age 10 of children with neurodevc\opmental disorders. II. School achievement problems. Develpm. Med. Child Neural .. 25:566-573. Goldstein. H. S. (1987). Cognitive development in low attentive. hyperactive. and aggressive 6- through II-year-old children. This journal. 26:214-218.
McGee. R.. Williams. S. & Silva, P. (1984). Behavioral and developmental characteristics of aggressive. hyperactive and aggressivehyperactive boys. This journal. 23:270-279. National Center for Health Statistics (1967). Plan. operation and response results ota program ofchildren 's examinations (Vital and Health Statistics. Series I. No.5). Washington. D.C: U.S. Government Printing Office. - - (1969). Plan and operation (If a health examination survey (If u.s youths 12-/7 years 0( age (Vital and Health Statistics. Series I. No.8). Washington. D.C: U.S. Government Printing Office. Roberts. J. (1971), lntetlcctual development 0( children (Vital and Health Statistics. Series II. No. 110). Washington. D.C: U.S. Government Printing Office. - - & Baird. J. T. (1972). Behavior patterns of children in school (Vital and Health Statistics. Series II. No. 113). Washington. D.C: U.S. Government Printing Office. SAS Institute Inc. (1982), .'lAS User's Guide: Statistics. 1982 cd, Cary. N.C: SAS Institute.
Method
In a report on the impact oflow attentiveness, hyperactivity, and aggressivity on cognitive development in a national probability sample of 6- through II-year-old children. the child attribute that predicted poor performance on intellectual and academic measures was lower than average attentiveness (Goldstein. 19H7). The critical question that follows is how persistent is this effect of low attentiveness on cognitive development. In New Zealand in a 2-year follow-up at age 9 of hyperactive. hyperactive-aggressive. and aggressive only children, McGee ct al. (1984) demonstrated lags in reading and spelling in the hyperactive children but not in those d isplaying aggressive behavior only. Gillberg et al. (1983), in Sweden, described reading, writing, and spelling lags in a 3-year follow-up at age 10 of minimally brain damaged children (defined as those with attention deficits plus motor and/or perception dysfunction) but not for those children with attention deficit disorder. Although both studies were carefully des igned to control for selection biases and social class . in neither was the baseline achievement level controlled. In the New Zealand study, given the degree of lag at the younger age, it was unclear whether the lag at follow-up was in addition to that described at age 7 or whether the lag was stable and still evident at age 9. Similarly, in the Gillberg report the lack of control for initial performance leaves open the question of whether the children with attention difficulties were developing at the same rate or were catching up at the time of the follow-up, In the stud y reported here, one third of the children in the orig inal national sample of 6- through II-year-olds were retested on the same cognitive measures between the ages of 12 and 17. 2 to 5 years after the initial testing. In the analysis of the data, the initial performance is controlled. as is famil v context. Thus the present stud y examines the elTect of the attributes of low attentiveness, hyperactivity. and aggressivity observed between 6 and II years of age on the youths' cognitive performance when the y are 12-17 years old,
Sample The data are from Cycle II (NCHS, 1967) and Cycle III (NCHS, 1969) of the Health Examination Surveys conducted by the National Center for Health Statistics of the U. S, Public Health Service. The sample design for both cycles used the same multistage probability sample of clustered households to provide representative samples of the 6- to II-year-old (Cycle II) and the 12- to 17-year-old (Cycle III) noninstitutionalized population of the United States. Because the same household clusters were used in Cycle III as in Cycle II, a substantial proportion of youths examined in Cycle II were reexamined in Cycle III. Two factors, however. age and family mobility. limited the number of reexamined children, More than one third of the children who were aged 6-11 during Cycle II were not yet age 12 at the time of Cycle III and were therefore not eligible for inclusion . Furthermore. in the interval between examinations, a substantial number of families moved from the household clusters being sampled and these youths were. consequently, not eligible for reexamination . Although those excluded because of age would not bias the sample in any way. the exclusion of children whose families moved can Introduce some socioeconomic bias, Socioeconomic status. however. was carefully controlled in this study, Nonetheless. the population reexamined. although substantial in number. is not as representative of the national cohort as is the total sample of either cycle . These reexamined youths still constitute the largest and most representative United States sample available for analysis to date. In sum, of the 7119 children examined in the Cycle II Survey. approximately one third were reexamined in Cycle III. permitting a comparison of their status at dilTerent ages. The pre sent study uses the data of the white youths because the yo uths of other races were too few in number for analyses across the many categories of behavior of the independent variable. In addition. only youths whose estimated IQ was 70 or greater at the Cycle II examination were included. The interval between the two examinations varied from 28 months 1053 months. with a mean interval of42.16 months. a median of 43 months. and a mode of 48 months.
Received Oct. 15. I'NU; revised Jan. Ii. IWlb; accepted Feb. 17,
tvs«
Dr. Goldstein is Associate Profrssor ofPsvchiutry at the Universit v o( Medicine and Dentistry (II' NCII' Jersey . Rutgers Medical Schuol, Pi .H·lI/(JI\·lIl', Nell' Jcrscv.
COXll it ivc Measures
Reqllesis.!ilr reprint .\--to Dr. Goldstein, Dept . ofPsvchiatrv. UM DNJ. RIIl!:er,1 Medical School, Piscutawav, NJ 08854. ' 0890-8567/87/2602-0219$02.00/0 (e) 1987 by the American Academy of Child and Adolescent Psychiatry.
As previously described. two subtests of the WISe, Vocabulary and Block Design. and two subtests of the WRAT, Reading and Arithmetic. were administered to evaluate intel~1 !1
220
GOLDSTEIN
lcctual development and school achievement. The subtest scores were standardized and are reported as T scores with a mean of 50 and a standard deviation of 10 (Roberts. 1971). An IQ estimate. the Intellectual Index. was computed by summing the Vocabulary and Block Design scores and setting the mean to 100 and S.D . to 15. An Achievement Index was sim ilarly computed by summing the Reading and Arithmetic subtc sts, setting the mean to 100 and S.D . to 15. Family Background (Contro! J'ariahles)
Three family characteristics known to influence cognitive development were controlled. These characteristics. parental edu cation. family income. and number of siblings. were combined into two covariates. The two family background covariates were parental education and income per sibling in household.
Classroom Behavior (Behavior Group Factor) The three areas of classroom behavior assessed by the school when the child was 6 to I I years old that are relevant to this study were attenti veness. acti vity level. and aggressivity (Robert s and Baird . 1972). A child described as lower than average in attentiveness was defined as low attentive: if the child was constantly on the move he was considered hyperactive; and if the child frequently required discipline for aggressive behavior. he was considered an aggressive child . These three attributes in combination yielded eight categories of behavior. Because of an insufficient number of children in one category (low attentive plus aggressive) at follow-up. seven categories were used : (a) low attentive; (b) hyperactive: (c) aggressive: (d) low attenti ve plus hyperactive; (e) hyperactive plus aggressive: (f) low attenti ve plus hyperacti ve plus aggressive: and (g) comparison . i.e.. children who were neither low attentive nor hyperactive nor aggressive. Data Analysis The statistical analysis used a one-way analysis of covariance (ANCOVA) with Behavior Group being the independent factor . The covariatcs were (a) the youth's score on the cognitive test during the previous survey (Cycle II). (b) the average parental education. and (c) the family income per sibling at the time of the follow-up . The statistics were computed using the General Linear Model procedure for unbalan ced designs of the Statistical Anal ysis System (SAS. 1982). The F tests usc. for the mean model var iance . the variance contributed to the model when the factor in question is included after the covariates are entered into the equation . The y are. therefore. tests of significance of the independent contribution of the factor to the variance of the outcome measures. When the F test proved significant. post hoc I tests were used to determine which means of the " pro blem" groups d iffered significantly from the comparison group. Given the number of comparisons. an alpha of 0.0 I was used for the I tests. Results
intelligence Tests As can be seen in Table I. the partially adjusted means show greater dispersion than the fully adjusted means between
TABLE I. Percentages I!I' Youths with Lilli' Attentiveness, lIY[Jl'fClCI;I';ly .
and AXX' l'.\·s; I'; I.I'
- - - - --
Percentage (N= 1616) -- .. _ _ . . _ --
Behavior Group Co m pa riso n Low att entive H yperact ive Aggressive Low attentive/hyperactive Hyperacti ve/aggressive Lowattenti ve/h yperactive/aggressive
77.16 14.66 0.68 1.55 2.60 0.68 2.66
the behavior groups. Even though the introduction of the previous test scores as a covariate reduces substantially the variance attributable to the Behavior Group factor, the factor remains significant for Vocabulary, F(6,1615) = 3.05; p = 0.0057; Block Design. F(6,1615) = 2.49: p = 0.0210: and Intellectual Index. F(6,1615) = 3.56: p = 0.0017 . The post hoc I tests demonstrated that significant differences resided between the comparison group and the low attentive group for the three measures (Table 2).
..tchievement Tests The ANCOV As were significant for the Reading, F(6,1615) = 4.61 : p = 0.0001 and Arithmetic. F(6,1615) = 10.05 : p = 0.000 I subtests and for the Achievement Index. F(6, 1615) = 8.16: P = 0.000 I. The post hoc I tests on the adjusted means
revealed that the three low attentive groups-low attentive. low attentive and hyperactive. and low attentive, hyperactive, and aggressive-were significantly different from the comparison group (T able 3). Because at ages 6-11. boys in the aggressive-only group showed lower achievement scores than the comparison group, an additional analysis of the male youths was made. The ANCOVA and post hoc I tests did not differ from values reported for boys and girls combined. The aggressive-only group mean for male youths was not significantly different from the comparison group mean. Discussion The fact that the low attentive group was significantly behind the comparison group. even with the initial cognitive performances controlled. points to the continuing impact of att ent ional problems on development into the adolescent years. an effect that goes beyond any initial disparity in cognitive development. Neither hyperactivity nor aggressivity playa significant role in this aspect of the child's development. Several explanations seem plausible for the worsening performance of the low attentive children. First , the low attentive behavior is likely to have continued (although in the absence of a follow-up assessment. th is can only be surmised) and made the acquisition of school-related knowledge and skills difficult. Second. a lag in earl y skill development and knowledge makes increasingly difficult the acquisition of more advanced skills. Thus failure to acquire average reading ability at age 7 will make acquiring the average vocabulary at age 10 more difficult. Additionally. there is the labeling of the child as a "poor learner" and the common practice of then tracking the child in a slow learner group. These actions may both
221
FOLLOW-UP OF INATTENTIVE CHILDREN TABLE 2. Adjusted" and Partially Adjusted" Means and SE. (If Intelligence Measures
~--.-_._-,-_.
IQ Index
Vocabulary
Block Design
N
Behavior Group
Adjusted
---------
Comparison
Mean (S.E.) Mean (S.E.) Mean (S.E.) Mean (S.E.) Mean (S.E.) Mean (S.E.) Mean (S.E.)
Low attentive Hyperactive Aggressive Low attentive/hyperactive Hyperacti velaggressi vc Low attentive/hyperactive/ aggressive
1247 237 II 25 42 II 43
Partial__
Adjusted
(105.76)
52.79 (0.17) 51.29' (0.39) 52.28 ( 1.79) 52.96 (1.88) 50.78 (0.92) 51.74 ( 1.78) 51.05 (0.91)
- - - _ . _ ~ - - - _ .
104.89 (0.24) 102.60' (0.56) 103.44 (2.58) 105.79 (1.71 ) 102.76 ( 1.32) 100.97 (2.57) 101.97 (l.3I)
(99.69) ( 103.95) (104.66) (98.23) ( 102.54) (97.28) ..
_
-
Partial
Adjusted
Partial
53.02 (0.21) 51.50" (0.47) 51.51 (2.18) 53.91 ( 1.45) 51.95 ( 1.12) 49.98 (2.18) 50.69 (1.11 )
(53.37)
. _--~~-
-----------~-
----
_..
(53.33) (49.51) (54.28) (52.18) (47.47) (53.13) (47.89)
(50.30) (50.20) (53.54) (50.66) (50.17) (49.01)
Adjusted for all covariates. " Adjusted for parental education and income but not for previous cognitive test scores. 'I' < 0.001. d I' < 0.01. u
TABLE 3. Adjusted" and Partially Adjusted" Means and SE. ofAchievement Measures ---_._--------
----
----
---
---,-~--
---------~----------~---------
Achievement Index Behavior Group -------
-
N
------------------
Adjusted
Partial
104.54 (0.22) 101.10' (0.52) 105.64 (2.35) 104.48 ( 1.56) 100.83" (1.21 ) 103.24 (2.35) 100.65" ( 1.20)
(105.90)
------------
Comparison
Mean (S.E.) Mean (S.E.) Mean (S.E.) Mean (S.E.) Mean (S.E.) Mean (S.E.) Mean (S.E.)
Low attentive Hyperactive Aggressive Low attentive/hyperactive Hyperacti ve] aggressi vc Low attentive/hyperactive/ aggressive ------
--
1247 237 II 25 42 II
43
(96.44) (105.83) ( 103.48) (95.05) (101.36) (93.41)
Reading -
Arithmetic
---------------
-------------------
Adjusted
Partial
Adjusted
Partial
52.76 (0.14) 51.22' (0.33) 52.95 ( 1.50) 53.57 ( 1.00) 51.20 (0.77) 51.90 (1.50) 50.58" (0.76)
(53.63)
52.97 (0.20) 49.57' ( 1.07) 5400 (2.09) 52.08 ( 1.39) 49.17" (1.07) 52.12 (2.09) 49.43" (1.07)
(53.62)
----------
(48.38) (53.87) (52.68) (46.91) (50.49) (45.94)
(47.24) (53.50) (51.65) (47.03) (51.11 ) (46.00) ---"---
" Adjusted for all co variates. " Adjusted for parental education and income but not for previous cognitive test scores. 'I' < 0.0001. "I' < 0.001. ,.I' < 0.0 I. discourage a child from putting forth the requisite effort and limit the opportunity to learn at an average or accelerated pace because of the curricular limitations of the slow learner group. Finally, because the low attentive children undoubtedly are a heterogenous group including children with depression and anxiety disorders. the untreated primary disorder may increasingly reduce the ability for focused attention. References Gillberg, I. C; Gillberg, C & Rasmussen. F. (1983). Three-year follow-up at age 10 of children with neurodevc\opmental disorders. II. School achievement problems. Develpm. Med. Child Neural .. 25:566-573. Goldstein. H. S. (1987). Cognitive development in low attentive. hyperactive. and aggressive 6- through II-year-old children. This journal. 26:214-218.
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