- Email: [email protected]
PKU as a factor in the development of self-esteem
B E H A V I O R A L
P E D I A T R I C S
Richard W. OImsted, Editor
P K U as a factor in the development of self-esteem* Self-esteem often children with phenylketonuria was compared with that of seven unaffected siblings of children w#h PKU in a total of l l families. Ages of the nine girls and eight boys ranged from 8 to 15 years. The study examined several variables that might affect self-esteem. From this study, it appears that PKU status and lowered IQ together contribute to lowered self-concept and that PKU status alone (i.e., with the effects of lQ removed) has a strong tendency to influence self-esteem.
Joan L. Moen, Robert D. Wilcox, and Joan K. Burns,** Madison, Wis.
THIS PRELIMINARY STUDY explored the self-esteem of children with phenylketonuria as compared with the self-esteem of unaffected siblings of children with PKU. Studies by Coopersmith,'. -' Stotland and Hillmer,:' and Witkin and associates 4 have pointed to the significance of self-esteem in determining behavior.
M E T H O D S AND M A T E R I A L S Procedure. This study was carried out within the University of Wisconsin-Madison Metabolic Program. The clinic, which primarily serves central and northern Wisconsin, has been regularly following children with metabolic disturbances since 1958, and offers medical, psychologic, dietary, and genetic services to these families. This study and the procedure used to obtain informed consent of the subjects' parents were approved by the From the Metabolic Clinic at the Harry A. Waisman Center on Mental Retardation and Human Development, School of Social Work, and Deoartment of Medical Genetics, University of Wisconsin. Support in part by Project Number It. E. W. 00046609-0, Grants No. MCT-O00915 MCT-O00268, Maternal and Child Health Service, Bureau of Community Health Services, Health Services Administration, Department of Health, Education and Welfare. *The research project was done by Joan Moen and Robert Wilcox in partial fulfillment of the requirements of the M.S.S. W. degree under the guidance of Joan K. Burns, M.S.S.W., Clinical Assistant Professor of the School of Social Work and Department of Medical Genetics, University of Wisconsin. **Reprint address: Woisman Center, 2605 Marsh Lane, University of Wisconsin, Madison, 14/1 53706.
Letters and Science Committee on the Use of Human Subjects, University of Wisconsin. Subjects. Our population of ten children with PKU represented the total clinic population which fit the necessary criteria for the study: early treatment (i.e., initiated prior to one month of age, except one subject in whom treatment was initiated at ten months) and appropriate age. The age range of 8 to 15 years was chosen because of the general belief that self-esteem is fairly well established by that age. Mean age of the PKU group was 10.4 years; the mean IQ was 88.6 based upon results of the Wechsler Intelligence Scale for Children in nine cases and the Stanford-Binet score in one. Seven of the ten were first-born: in two families the PKU child was second-born and one was the sixth of seven children. Four in the group were girls and six were boys. Abbreviations used PKU: phenylketonuria IQ: intelligence quotient WISC: Wechsler Intelligence Scale for children SB: Stanford-Binet CSEI: Coopersmith's Self-Esteem Inventory Seven unaffected siblings of children with PK!! ~d,.,~ represented almost the total age-appropriate population from metabolic program files. The mean age for this group was 10.7 years: the mean IQ was 94.4 based upon results of the WISC in three children and the SB score in four. Birth order for this group was widely scattered. Five of the group were girls and two were boys. Socioeconomic status of the 11 families was generally middle class: eight families had incomes of $15,000 or more: two families earned from $10.000 to $15,000. and The Journal of P E D I A T R I C S Vol. 90, No. 6, pp. 1027-1029
1027
10 2 8
Moen, Wilcox, and Burns
I00
The Journal of Pediatrics June 1977
0
tionnaire. Instructions are clearly stated at the top of the form ,(i.e., if the statement describes how you usually feel, check the "Like Me" column). The 50 scored items are subdivided into a total of four subscales: (1) general self; (2) social self-peers; (3) home-parents; .and (4) schoolacademic. Each of the 50 items has a weight of 2, making the possible total of 100. Tests were administered individually at the clinic by the investigators as part o f the regular follow-up. In ten cases no clinic visit was scheduled and questionnaires were mailed to the subjects' homes to be administered by parents.
0
0
gO 0
0
80 ell
0
70 uJ o
Q
(J
6O
RESULTS 5G
ri
9
4C
I 7'0
30
I
I 100
L 90 I0
80
I , II0
J 120
Fig. 1. Graph relating CSEI and IQ of ten PKU and seven non-
PKU subjects (N = 17). Black circies= PKU girls; black squares = PKU boys; white circles = unaffected girls; and white squares = unaffected boys. Table I. Self-esteem and IQ in five families
IQ
Sex
Family Code PKU [ Sib 1
2* 2 3 4 5
002 101 OO4 102 004 103 O05 104 006 109 009 110
Self-concept
PKU [ Sib
PKU
Sib
M
F
84
92
76
98
M
M
78
95
62
86
M
M
78
86
62
84
M
F
83
110
92
98
F
F
109
96
64
76
M
F
88
81
46
94
86.6
93.3
67
86
Scores for each child were computed according to Coopersmith's key. Mean score for the PKU group was 65.8 compared to 86 for the control group. Individual scores are shown in Fig. 1. A simple correlation between PKU status and self-esteem was found to be significant at p < 0.05 (r = 0.545). With the effects of IQ removed, the correlation between self-esteem and PKU status was still significant at p _< 0.05 (r -- 0.503). Correlation between IQ and self-esteem (r = 0.413) and between IQ and PKU (r = 0.245) were not significant. The data also revealed that the correlation between age and self-esteem and between sex and self-esteem were not significant, though there was a tendency for girls' self-esteem to be higher. IQ scores of children with PKU were not significantly different from those of siblings. To determine if any single area had a disproportionate effect on the overall scores, sub-scores were computed for each of the four subscales measured, i.e., (1) general self; (2) social self-peers; (3) home-parents; and (4) school-academic. The subscores for both the PKU and control groups were found to be proportionately distributed across all four areas. Table I shows CSEI and IQ scores for only those PKU children and siblings who were from the same family, to show relationships within families. DISCUSSION
Mean scores *This child is compared with two sibs.
one family earned less than $10,000 annually. Five of the control children were sibs of the affected patients. All of the affected children were off diet a~ the time of the study. Instrument. Coopersmith's Self-Esteem Inventory was used since normative data were available. The instrument, designed especially for children from approximately 9 to 14 years of age, is a self-inventory with children responding to a simple paper-and-pencil 50-item ques-
The literature suggests that children with PKU may have lower self-esteem for several "diet-management"-related reasons. SmLth, 5 in a Wisconsin study of seven intact nuclear families with a total of 12 phenylketonuric children, suggested that the necessity of maintaining a special diet and the management of the diet may contribute to lowered self-esteem. The literature also cites family tension centering around the child with PKU. Sylvia Schild, ~ in a study of 23 families, reported that management of the PKU diet may have aggravated problems of parental feelings and attitudes for one-third of those in the group. According to a recent study by Dobson and associates, 7 "the suggestion has been made
Volume 90 Number 6
that the imposition of a special diet, while preventing severe mental retardation, may in itself cause certain intellectual or emotional impairments." The purpose of this study was to determine whether there were differences in self-esteem between previously treated PKU children and non-PKU siblings. Differences were found to exist: in general, children with PKU scored lower on measures of self-esteem than normal siblings. Though many factors obviously influence self-esteem, it appeared from this study that both PKU status and lowered IQ contributed to lowered self-esteem. With the effects of IQ removed, PKU status still had a strong tendency to influence self-esteem. It should be noted that IQ scores for the PKU group were all obtained within the last year, whereas those of siblings were less recent (most scores were obtained five to six years ago). It is possible that more recent scores might tend to alter the relationship of IQ and PKU with self-esteem. It would appear from these preliminary studies that children with PKU are at risk for having lowered selfesteem. Among other things, this may be due to the fact that the child had previously required a special diet or be related to the manner in which diet management was handled. Another factdr which could possibly have an influence on the development of a child's self-esteem might be constant awareness of having a "special" conditon and therefore being different from others.
PKU in the development of self-esteem
10 2 9
Finally, one cannot dismiss the possible consequences of being taken off the diet and the effect that high plasma phenylalanine concentrations may have on personality or behavior. Though more research is needed, the results do seem to have relevance for professionals working with PKU children and their families. REFERENCES
1. Coopersmith S: The antecedents of self-esteem, San Francisco, 1967, WH Freeman & Company. 2. Coopersmith S: Relationship between self-esteem and sensory (perceptual) constancy, J Abnorm Soc Psychol 68:221, 1964. 3. Stotland E, and Hillmer ML Jr: Identification, authoritarian defensiveness, and self-esteem, J Abnorm Soc Psychol 64"334, 1962. 4. Witkins HA, Dyk RB, Faterson HF, Goodenough DR, and Karp SA: Psychological differentiation: Studies of development, New York, 1962, John Wiley & Sons, Inc. 5. Smith I: Observation of seven families with one or more phenylketonuric children under treatment, unpublished paper presented at Annual Meeting of the American Orthopsychiatric Association, 1965. 6. Schild S: Family attitudes and the low-phenylalanine diet. The clinical team looks at phenylketonuria, brochure, United States Department of Health, Education and Welfare, Children's Bureau, Washington, DC, 1961. 7. Dobson JD, Kushida E, Williamson M, and Friedman EG: Intellectual performance of 36 phenylketonuria patients and their nonaffected siblings, Pediatrics 58:53, 1976.
P E D I A T R I C S
Richard W. OImsted, Editor
P K U as a factor in the development of self-esteem* Self-esteem often children with phenylketonuria was compared with that of seven unaffected siblings of children w#h PKU in a total of l l families. Ages of the nine girls and eight boys ranged from 8 to 15 years. The study examined several variables that might affect self-esteem. From this study, it appears that PKU status and lowered IQ together contribute to lowered self-concept and that PKU status alone (i.e., with the effects of lQ removed) has a strong tendency to influence self-esteem.
Joan L. Moen, Robert D. Wilcox, and Joan K. Burns,** Madison, Wis.
THIS PRELIMINARY STUDY explored the self-esteem of children with phenylketonuria as compared with the self-esteem of unaffected siblings of children with PKU. Studies by Coopersmith,'. -' Stotland and Hillmer,:' and Witkin and associates 4 have pointed to the significance of self-esteem in determining behavior.
M E T H O D S AND M A T E R I A L S Procedure. This study was carried out within the University of Wisconsin-Madison Metabolic Program. The clinic, which primarily serves central and northern Wisconsin, has been regularly following children with metabolic disturbances since 1958, and offers medical, psychologic, dietary, and genetic services to these families. This study and the procedure used to obtain informed consent of the subjects' parents were approved by the From the Metabolic Clinic at the Harry A. Waisman Center on Mental Retardation and Human Development, School of Social Work, and Deoartment of Medical Genetics, University of Wisconsin. Support in part by Project Number It. E. W. 00046609-0, Grants No. MCT-O00915 MCT-O00268, Maternal and Child Health Service, Bureau of Community Health Services, Health Services Administration, Department of Health, Education and Welfare. *The research project was done by Joan Moen and Robert Wilcox in partial fulfillment of the requirements of the M.S.S. W. degree under the guidance of Joan K. Burns, M.S.S.W., Clinical Assistant Professor of the School of Social Work and Department of Medical Genetics, University of Wisconsin. **Reprint address: Woisman Center, 2605 Marsh Lane, University of Wisconsin, Madison, 14/1 53706.
Letters and Science Committee on the Use of Human Subjects, University of Wisconsin. Subjects. Our population of ten children with PKU represented the total clinic population which fit the necessary criteria for the study: early treatment (i.e., initiated prior to one month of age, except one subject in whom treatment was initiated at ten months) and appropriate age. The age range of 8 to 15 years was chosen because of the general belief that self-esteem is fairly well established by that age. Mean age of the PKU group was 10.4 years; the mean IQ was 88.6 based upon results of the Wechsler Intelligence Scale for Children in nine cases and the Stanford-Binet score in one. Seven of the ten were first-born: in two families the PKU child was second-born and one was the sixth of seven children. Four in the group were girls and six were boys. Abbreviations used PKU: phenylketonuria IQ: intelligence quotient WISC: Wechsler Intelligence Scale for children SB: Stanford-Binet CSEI: Coopersmith's Self-Esteem Inventory Seven unaffected siblings of children with PK!! ~d,.,~ represented almost the total age-appropriate population from metabolic program files. The mean age for this group was 10.7 years: the mean IQ was 94.4 based upon results of the WISC in three children and the SB score in four. Birth order for this group was widely scattered. Five of the group were girls and two were boys. Socioeconomic status of the 11 families was generally middle class: eight families had incomes of $15,000 or more: two families earned from $10.000 to $15,000. and The Journal of P E D I A T R I C S Vol. 90, No. 6, pp. 1027-1029
1027
10 2 8
Moen, Wilcox, and Burns
I00
The Journal of Pediatrics June 1977
0
tionnaire. Instructions are clearly stated at the top of the form ,(i.e., if the statement describes how you usually feel, check the "Like Me" column). The 50 scored items are subdivided into a total of four subscales: (1) general self; (2) social self-peers; (3) home-parents; .and (4) schoolacademic. Each of the 50 items has a weight of 2, making the possible total of 100. Tests were administered individually at the clinic by the investigators as part o f the regular follow-up. In ten cases no clinic visit was scheduled and questionnaires were mailed to the subjects' homes to be administered by parents.
0
0
gO 0
0
80 ell
0
70 uJ o
Q
(J
6O
RESULTS 5G
ri
9
4C
I 7'0
30
I
I 100
L 90 I0
80
I , II0
J 120
Fig. 1. Graph relating CSEI and IQ of ten PKU and seven non-
PKU subjects (N = 17). Black circies= PKU girls; black squares = PKU boys; white circles = unaffected girls; and white squares = unaffected boys. Table I. Self-esteem and IQ in five families
IQ
Sex
Family Code PKU [ Sib 1
2* 2 3 4 5
002 101 OO4 102 004 103 O05 104 006 109 009 110
Self-concept
PKU [ Sib
PKU
Sib
M
F
84
92
76
98
M
M
78
95
62
86
M
M
78
86
62
84
M
F
83
110
92
98
F
F
109
96
64
76
M
F
88
81
46
94
86.6
93.3
67
86
Scores for each child were computed according to Coopersmith's key. Mean score for the PKU group was 65.8 compared to 86 for the control group. Individual scores are shown in Fig. 1. A simple correlation between PKU status and self-esteem was found to be significant at p < 0.05 (r = 0.545). With the effects of IQ removed, the correlation between self-esteem and PKU status was still significant at p _< 0.05 (r -- 0.503). Correlation between IQ and self-esteem (r = 0.413) and between IQ and PKU (r = 0.245) were not significant. The data also revealed that the correlation between age and self-esteem and between sex and self-esteem were not significant, though there was a tendency for girls' self-esteem to be higher. IQ scores of children with PKU were not significantly different from those of siblings. To determine if any single area had a disproportionate effect on the overall scores, sub-scores were computed for each of the four subscales measured, i.e., (1) general self; (2) social self-peers; (3) home-parents; and (4) school-academic. The subscores for both the PKU and control groups were found to be proportionately distributed across all four areas. Table I shows CSEI and IQ scores for only those PKU children and siblings who were from the same family, to show relationships within families. DISCUSSION
Mean scores *This child is compared with two sibs.
one family earned less than $10,000 annually. Five of the control children were sibs of the affected patients. All of the affected children were off diet a~ the time of the study. Instrument. Coopersmith's Self-Esteem Inventory was used since normative data were available. The instrument, designed especially for children from approximately 9 to 14 years of age, is a self-inventory with children responding to a simple paper-and-pencil 50-item ques-
The literature suggests that children with PKU may have lower self-esteem for several "diet-management"-related reasons. SmLth, 5 in a Wisconsin study of seven intact nuclear families with a total of 12 phenylketonuric children, suggested that the necessity of maintaining a special diet and the management of the diet may contribute to lowered self-esteem. The literature also cites family tension centering around the child with PKU. Sylvia Schild, ~ in a study of 23 families, reported that management of the PKU diet may have aggravated problems of parental feelings and attitudes for one-third of those in the group. According to a recent study by Dobson and associates, 7 "the suggestion has been made
Volume 90 Number 6
that the imposition of a special diet, while preventing severe mental retardation, may in itself cause certain intellectual or emotional impairments." The purpose of this study was to determine whether there were differences in self-esteem between previously treated PKU children and non-PKU siblings. Differences were found to exist: in general, children with PKU scored lower on measures of self-esteem than normal siblings. Though many factors obviously influence self-esteem, it appeared from this study that both PKU status and lowered IQ contributed to lowered self-esteem. With the effects of IQ removed, PKU status still had a strong tendency to influence self-esteem. It should be noted that IQ scores for the PKU group were all obtained within the last year, whereas those of siblings were less recent (most scores were obtained five to six years ago). It is possible that more recent scores might tend to alter the relationship of IQ and PKU with self-esteem. It would appear from these preliminary studies that children with PKU are at risk for having lowered selfesteem. Among other things, this may be due to the fact that the child had previously required a special diet or be related to the manner in which diet management was handled. Another factdr which could possibly have an influence on the development of a child's self-esteem might be constant awareness of having a "special" conditon and therefore being different from others.
PKU in the development of self-esteem
10 2 9
Finally, one cannot dismiss the possible consequences of being taken off the diet and the effect that high plasma phenylalanine concentrations may have on personality or behavior. Though more research is needed, the results do seem to have relevance for professionals working with PKU children and their families. REFERENCES
1. Coopersmith S: The antecedents of self-esteem, San Francisco, 1967, WH Freeman & Company. 2. Coopersmith S: Relationship between self-esteem and sensory (perceptual) constancy, J Abnorm Soc Psychol 68:221, 1964. 3. Stotland E, and Hillmer ML Jr: Identification, authoritarian defensiveness, and self-esteem, J Abnorm Soc Psychol 64"334, 1962. 4. Witkins HA, Dyk RB, Faterson HF, Goodenough DR, and Karp SA: Psychological differentiation: Studies of development, New York, 1962, John Wiley & Sons, Inc. 5. Smith I: Observation of seven families with one or more phenylketonuric children under treatment, unpublished paper presented at Annual Meeting of the American Orthopsychiatric Association, 1965. 6. Schild S: Family attitudes and the low-phenylalanine diet. The clinical team looks at phenylketonuria, brochure, United States Department of Health, Education and Welfare, Children's Bureau, Washington, DC, 1961. 7. Dobson JD, Kushida E, Williamson M, and Friedman EG: Intellectual performance of 36 phenylketonuria patients and their nonaffected siblings, Pediatrics 58:53, 1976.