Psychological Reports, 1990, 67, 1235-1242. O Psychological Reports 1990
HOMICIDAL ADOLESCENTS: A REPLICATION
'
ROBERT ZAGAR, JACK ARBIT, ROBERT SYLVIES, KENNETH G . BUSCH AND JOHN R. HUGHES
Juvenile Division of Circuit Court of Cook County Northwestern University Medical School Loyola University Stritch College of Medicine lllinois School of Professional Psychology University of Illinois at Chicago College of Medicine Summary.-30 homicidal delinquents were matched with 30 nonviolent delinquents on age, race, sex, and socioeconomic status. Both groups received physical, psychological, educational, psychiatric and social examinations. Data were evaluated using stepwise discriminant analysis. Previous research was replicated. Homicidal adolescents shared four symptoms: criminally violent families, gang participation, alcohol abuse, severe learning difficulties. In addition, when the sample and the original group of murderers were combined the contrast between groups became clearer. Juvenile murderers lived in criminally violent families learning aggression during early childhood. Cognitive and perceptual deficits associated with epilepsy and central nervous system (CNS) conditions led to difficulties in the school years. During adolescence, gang participation and alcohol abuse added to earlier risk factors.
For centuries people have been interested in why adolescents commit murder. Traditionally, investigators have looked at families of homicidal adolescents. Recently, popular opinion has focused on gang participation with substance abuse among urban juvenile murderers. Despite current understanding and treatment, homicide rates among adolescents continue to increase, especially in urban industrial areas (Blum, 1987). The purpose of this study was to see if earlier results or descriptions of urban juvenile murderers could be replicated. Researchers and clinicians had identified adolescents who murdered using data from biological, medical, psychological, educational, psychiatric, sociological, and biopsychosocia.l approaches (Bender & Curran, 1940; Bender, 1959; Deykin, Levy, & Wells, 1987; Duncan & Duncan, 1971; Easson & Steenhilber, 1961; Freud, 1939; King, 1975; Lewis, Pincus, Feldman, Jackson, & Baird, 1986; Lewis, Lovely, Yeager, Ferguson, Freidman, & Pincus, 1988; MacDonald, 1967; Malmquist, 1971; Miller & Looney, 1974; 'The authors ex ress their gratitude for the assistance of Jud e Arthur Hamilton, Tom Jones, John Hahn, a n 1James Jordan for providing access to the fata; to Toya Woullard, Edward McClinton, Tom Baglajewski, Sherry Perry, Susan Flamagan, Darek Jakubowski, Lynn Hume, and Contantina Theodorou for data collection, computer entry and patient ratings; and to Drs. Jura Adams, Norman D. Bowers, Robert E . Bussell, and Dorothy Lewis for their comments on earlier versions of this manuscript. This research is partially funded from the Edith Schiller Research Fund, Northwesrern Memorial Hospital. Reprints may be requested of Dr. ; : ~ k ~ t , Department of Psychiatry, Northwestern University Medical School, 303 East Chicago Avenue, Chicago, IL 60611.
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R. ZAGAR, ET AL.
Offord, Allen, & Abrams, 1975; Satten, Menninger, & Rosen, 1960; Sendi & Blomgren, 1974; Smith, 1965; Stearns, 1975; Tooley, 1975). Despite these efforts past research on adolescents who murdered has often been anecdotal comparing case studies or small groups on a few variables without replicating earlier results. Busch, Zagar, Arbit, Hughes, and Bussell (1990) incorporated biopsychosocial factors in a population of 71 adolescents who committed murder. A tetrad of symptoms separated juvenile murderers from matched nonviolent delinquents: (a) criminally violent families, (b) gang participation, (c) alcohol abuse, and (d) severe learning difficulties. The goal of this study was to replicate earlier results of Busch, Zagar, Arbit, Hughes, and Bussell (1990) in using the original discriminant function predictor weights to separate homicidal adolescents from nonviolent delinquents, who were matched by age, race, sex, and socioeconomic status. The null hypothesis of this study was that adolescents who killed would not differ from matched nonviolent delinquents in having combinations of criminally violent families, gang participation, alcohol abuse, and severe educational difficulties when the original discriminant function coefficients of predictor variables from Busch, et al. (1990) were used.
Subjects (Independent Variables) There were 30 adjudicated (judged within a court) juveniles (2 girls and 28 boys), aged 10 to 17 yr. (M= 14.6 yr. f 1.3), all of whom committed and were convicted of homicide. Homicides were familial, random, friend, drugor gang-related. The control group included 30 adolescents who were matched by age, race, sex, and socioeconomic status. This control group was composed of nonviolent delinquents adjudicated for offenses of criminal property damage, theft, truancy, violating court order, curfew or probation. The homicidal and control groups of juveniles received complete physical, psychological, educational, psychiatric and social evaluations. The two groups of homicidal juveniles and matched nonviolent delinquents were lower class (less than $8,000/year/family), as were the sample of 2,016 delinquents from whom they were selected. Socioeconomic status was established using family income, parental occupation and area of residence. This group of 30 homicidal juveniles represented every delinquent charged with homicide from the sample of 2,016 but not from the larger population of 42,655 who were evaluated from 1981 to 1988. The original 71 homicidal juveniles evaluated from 1981 to 1986 were described earlier (Busch, et al., 1990; Zagar, Arbit, Hughes, Bussell, & Busch, 1989). This sample of 2,016 consisted of all adjudicated delinquents who had complete records and who were referred for physical, psychological, educational, psychiatric and social
HOMICIDAL ADOLESCENTS
1237
examinations. Adolescents who had not received the latter examinations were excluded from this sample. The sample of 2,016 delinquents was from a larger population of adolescents, totalling 42,655 or approximately 5% of the population of adjudicated delinquents. This sample and the population were retrospective, not random and reflected the selection bias in the adjudication and referral of delinquents. Moreover, the examiners' knowledge of the murderer reflected experimenter bias in this post hoc study. In an attempt to show that the population of 42,655, the sample of 2,016, and the combined groups of homicidal and matched nonviolent delinquents (60) were similar, the following comparisons of age, race, sex and family composition were made: age (14.4 f 1.3 vs 13.9 + 1.9 vs 14.6 + 1.3); race (black: 64% vs 60% vs 57%, white: 24% vs 29% vs 20%, Hispanic: 11% vs 10% vs 23%, other: 1% vs 1% vs 0%); sex. male-female ratio (80%-20% vs 80%-20% vs 98%-2%); family composition: orphans (6% vs 4% vs 0%); single parents (60% vs 65% vs 67%); step-parents (19% vs 14% vs 10%) and two unseparated biological parents (15% vs 17% vs 23%); medical conditions: pneumonia rate (3% vs 3% vs 4%); tuberculosis (4% vs 5% vs 3%); visual impairment (9% vs 14% vs 14%); head injury (10% vs 13% vs 13%); physical abuse (15% vs 22% vs 33%); and retardation (12% vs 15% vs 15%).
Dependent Variables Physical examinations were performed by pediatricians to discover central nervous system (CNS) conditions, neonatal problems, psychological disturbances, and substance abuse, which were coded using the International Classification of Diseases (ICD-9). The medical histories obtained at the time of referral included review of hospital, neonatal records and a thorough pediatric examination of neurological, respiratory, musculoskeletal, circulatory, gastrointestinal, hepatic, renal, genitourinary, endocrine and slun systems. CNS conditions included visual, hearing and speech impairments, headaches, blackouts, tremors, epilepsy, head and neck injury, skull fracture, and hydrocephalus. Neonatal problems were anoxia, prematurity, fetal alcohol or heroin syndrome, neonatal diabetes, infant apnea, and jaundice. Substance abuse included at least weekly use of one or more of the following substances: alcohol, marijuana, cocaine, lysergic acid diethylamide, amphetamines, aromatics (paint and glue sniffing), and heroin. Psychological and educational examinations consisted of the Wechsler Intelligence Scale for Children-Revised (Wechsler, 1974) and the Bender Visual-motor Gestalt Test (Bender, 1938) scored by the Koppitz (1964) method for errors using two independent raters. Gates-MacGinitie Reading Tests (Gates & MacGinitie, 1965), Survey D, Form 1, which entailed reading speed and accuracy, vocabulary, and reading comprehension of paragraphs and (2) the Stanford Achievement Tests (Kelly, Madden, Gardner, &
1238
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Ruderman, 1964), Form W, Intermediate I, which incorporated addition, subtraction, multiplication and division. Developmental and disruptive behavioral disorders were classified by two psychologists working independently using data from physical, psychological, psychiatric, educational and social examinations within Diagnostic Statistical Manual 111-Revised (DSM-111-R) criteria. The major DSM111-R categories were: (a) mental retardation, (b) attention deficit-hyperactivity disorder (ADHD), (c) attention deficit disorder (ADD) undifferentiated, and (d) developmental delays in reading, language and arithmetic. For retardation, A D H D and ADD, the coefficients of interobserver agreement (Pearson r) for the two independent raters were .94 ( p < .01), .92 (p
HOMICIDAL ADOLESCENTS: A REPLICATION
'
ROBERT ZAGAR, JACK ARBIT, ROBERT SYLVIES, KENNETH G . BUSCH AND JOHN R. HUGHES
Juvenile Division of Circuit Court of Cook County Northwestern University Medical School Loyola University Stritch College of Medicine lllinois School of Professional Psychology University of Illinois at Chicago College of Medicine Summary.-30 homicidal delinquents were matched with 30 nonviolent delinquents on age, race, sex, and socioeconomic status. Both groups received physical, psychological, educational, psychiatric and social examinations. Data were evaluated using stepwise discriminant analysis. Previous research was replicated. Homicidal adolescents shared four symptoms: criminally violent families, gang participation, alcohol abuse, severe learning difficulties. In addition, when the sample and the original group of murderers were combined the contrast between groups became clearer. Juvenile murderers lived in criminally violent families learning aggression during early childhood. Cognitive and perceptual deficits associated with epilepsy and central nervous system (CNS) conditions led to difficulties in the school years. During adolescence, gang participation and alcohol abuse added to earlier risk factors.
For centuries people have been interested in why adolescents commit murder. Traditionally, investigators have looked at families of homicidal adolescents. Recently, popular opinion has focused on gang participation with substance abuse among urban juvenile murderers. Despite current understanding and treatment, homicide rates among adolescents continue to increase, especially in urban industrial areas (Blum, 1987). The purpose of this study was to see if earlier results or descriptions of urban juvenile murderers could be replicated. Researchers and clinicians had identified adolescents who murdered using data from biological, medical, psychological, educational, psychiatric, sociological, and biopsychosocia.l approaches (Bender & Curran, 1940; Bender, 1959; Deykin, Levy, & Wells, 1987; Duncan & Duncan, 1971; Easson & Steenhilber, 1961; Freud, 1939; King, 1975; Lewis, Pincus, Feldman, Jackson, & Baird, 1986; Lewis, Lovely, Yeager, Ferguson, Freidman, & Pincus, 1988; MacDonald, 1967; Malmquist, 1971; Miller & Looney, 1974; 'The authors ex ress their gratitude for the assistance of Jud e Arthur Hamilton, Tom Jones, John Hahn, a n 1James Jordan for providing access to the fata; to Toya Woullard, Edward McClinton, Tom Baglajewski, Sherry Perry, Susan Flamagan, Darek Jakubowski, Lynn Hume, and Contantina Theodorou for data collection, computer entry and patient ratings; and to Drs. Jura Adams, Norman D. Bowers, Robert E . Bussell, and Dorothy Lewis for their comments on earlier versions of this manuscript. This research is partially funded from the Edith Schiller Research Fund, Northwesrern Memorial Hospital. Reprints may be requested of Dr. ; : ~ k ~ t , Department of Psychiatry, Northwestern University Medical School, 303 East Chicago Avenue, Chicago, IL 60611.
1236
R. ZAGAR, ET AL.
Offord, Allen, & Abrams, 1975; Satten, Menninger, & Rosen, 1960; Sendi & Blomgren, 1974; Smith, 1965; Stearns, 1975; Tooley, 1975). Despite these efforts past research on adolescents who murdered has often been anecdotal comparing case studies or small groups on a few variables without replicating earlier results. Busch, Zagar, Arbit, Hughes, and Bussell (1990) incorporated biopsychosocial factors in a population of 71 adolescents who committed murder. A tetrad of symptoms separated juvenile murderers from matched nonviolent delinquents: (a) criminally violent families, (b) gang participation, (c) alcohol abuse, and (d) severe learning difficulties. The goal of this study was to replicate earlier results of Busch, Zagar, Arbit, Hughes, and Bussell (1990) in using the original discriminant function predictor weights to separate homicidal adolescents from nonviolent delinquents, who were matched by age, race, sex, and socioeconomic status. The null hypothesis of this study was that adolescents who killed would not differ from matched nonviolent delinquents in having combinations of criminally violent families, gang participation, alcohol abuse, and severe educational difficulties when the original discriminant function coefficients of predictor variables from Busch, et al. (1990) were used.
Subjects (Independent Variables) There were 30 adjudicated (judged within a court) juveniles (2 girls and 28 boys), aged 10 to 17 yr. (M= 14.6 yr. f 1.3), all of whom committed and were convicted of homicide. Homicides were familial, random, friend, drugor gang-related. The control group included 30 adolescents who were matched by age, race, sex, and socioeconomic status. This control group was composed of nonviolent delinquents adjudicated for offenses of criminal property damage, theft, truancy, violating court order, curfew or probation. The homicidal and control groups of juveniles received complete physical, psychological, educational, psychiatric and social evaluations. The two groups of homicidal juveniles and matched nonviolent delinquents were lower class (less than $8,000/year/family), as were the sample of 2,016 delinquents from whom they were selected. Socioeconomic status was established using family income, parental occupation and area of residence. This group of 30 homicidal juveniles represented every delinquent charged with homicide from the sample of 2,016 but not from the larger population of 42,655 who were evaluated from 1981 to 1988. The original 71 homicidal juveniles evaluated from 1981 to 1986 were described earlier (Busch, et al., 1990; Zagar, Arbit, Hughes, Bussell, & Busch, 1989). This sample of 2,016 consisted of all adjudicated delinquents who had complete records and who were referred for physical, psychological, educational, psychiatric and social
HOMICIDAL ADOLESCENTS
1237
examinations. Adolescents who had not received the latter examinations were excluded from this sample. The sample of 2,016 delinquents was from a larger population of adolescents, totalling 42,655 or approximately 5% of the population of adjudicated delinquents. This sample and the population were retrospective, not random and reflected the selection bias in the adjudication and referral of delinquents. Moreover, the examiners' knowledge of the murderer reflected experimenter bias in this post hoc study. In an attempt to show that the population of 42,655, the sample of 2,016, and the combined groups of homicidal and matched nonviolent delinquents (60) were similar, the following comparisons of age, race, sex and family composition were made: age (14.4 f 1.3 vs 13.9 + 1.9 vs 14.6 + 1.3); race (black: 64% vs 60% vs 57%, white: 24% vs 29% vs 20%, Hispanic: 11% vs 10% vs 23%, other: 1% vs 1% vs 0%); sex. male-female ratio (80%-20% vs 80%-20% vs 98%-2%); family composition: orphans (6% vs 4% vs 0%); single parents (60% vs 65% vs 67%); step-parents (19% vs 14% vs 10%) and two unseparated biological parents (15% vs 17% vs 23%); medical conditions: pneumonia rate (3% vs 3% vs 4%); tuberculosis (4% vs 5% vs 3%); visual impairment (9% vs 14% vs 14%); head injury (10% vs 13% vs 13%); physical abuse (15% vs 22% vs 33%); and retardation (12% vs 15% vs 15%).
Dependent Variables Physical examinations were performed by pediatricians to discover central nervous system (CNS) conditions, neonatal problems, psychological disturbances, and substance abuse, which were coded using the International Classification of Diseases (ICD-9). The medical histories obtained at the time of referral included review of hospital, neonatal records and a thorough pediatric examination of neurological, respiratory, musculoskeletal, circulatory, gastrointestinal, hepatic, renal, genitourinary, endocrine and slun systems. CNS conditions included visual, hearing and speech impairments, headaches, blackouts, tremors, epilepsy, head and neck injury, skull fracture, and hydrocephalus. Neonatal problems were anoxia, prematurity, fetal alcohol or heroin syndrome, neonatal diabetes, infant apnea, and jaundice. Substance abuse included at least weekly use of one or more of the following substances: alcohol, marijuana, cocaine, lysergic acid diethylamide, amphetamines, aromatics (paint and glue sniffing), and heroin. Psychological and educational examinations consisted of the Wechsler Intelligence Scale for Children-Revised (Wechsler, 1974) and the Bender Visual-motor Gestalt Test (Bender, 1938) scored by the Koppitz (1964) method for errors using two independent raters. Gates-MacGinitie Reading Tests (Gates & MacGinitie, 1965), Survey D, Form 1, which entailed reading speed and accuracy, vocabulary, and reading comprehension of paragraphs and (2) the Stanford Achievement Tests (Kelly, Madden, Gardner, &
1238
R. ZAGAR, ETAL.
Ruderman, 1964), Form W, Intermediate I, which incorporated addition, subtraction, multiplication and division. Developmental and disruptive behavioral disorders were classified by two psychologists working independently using data from physical, psychological, psychiatric, educational and social examinations within Diagnostic Statistical Manual 111-Revised (DSM-111-R) criteria. The major DSM111-R categories were: (a) mental retardation, (b) attention deficit-hyperactivity disorder (ADHD), (c) attention deficit disorder (ADD) undifferentiated, and (d) developmental delays in reading, language and arithmetic. For retardation, A D H D and ADD, the coefficients of interobserver agreement (Pearson r) for the two independent raters were .94 ( p < .01), .92 (p
