Aggression, Victimization, and Aggressor/Victim Subgroups
Although peer nomination is considered the gold standard for assessing aggressor/victim classifications (Perry, Kusel, & Perry, 1988
) this approach was not feasible in the present study as children were enrolled in over 300 classrooms. Thus, a multi-informant approach based on mother, teacher, and child reports of peer aggression and victimization was utilized (Burk et al., 2008
). Adult interview versions of the MacArthur Health and Behavior Questionnaire [HBQ; (Boyce et al., 2002
; Essex et al., 2002
)] and modules from the Berkeley Puppet Interview (BPI) developed in tandem with the HBQ to provide parallel child self-reports (Ablow, Measelle, & MacArthur Working Group on Outcome Assessment, 2003
) yielded scores for Overt Aggression, Relational Aggression, and Bullied by Peers. Mothers and teachers were interviewed at Grades 1, 3, and 5. Children completed the BPI at Grade 1 and an age-appropriate questionnaire modeled on the BPI, the HBQ-Child form (HBQ-C), at Grades 3 and 5.
On the mother and teacher HBQ interviews, 4 items tapped Overt Aggression (OA; e.g., “Gets in many fights”), 6 items tapped Relational Aggression (RA; e.g., “Tries to get others to dislike a peer”), and 3 items tapped Bullied by Peers (BP; e.g., “Is teased and ridiculed by other children”). Overt Aggression and Relational Aggression items were rated on a 3-point scale ranging from 0 (never or not true) to 2 (often or very true). Items from the Bullied by Peers scale were rated on a 4-point scale ranging from 1 (not at all like) to 4 (very much like). Scale scores were calculated separately for each reporter. Coefficients α were acceptable for all scales and are presented for mothers and teachers, respectively: OA (Grade 1, 0.63 and 0.76; Grade 3, 0.62 and 0.79; Grade 5, 0.50 and 0.63); RA (Grade 1, 0.76 and 0.86; Grade 3, 0.85 and 0.92; Grade 5, 0.82 and 0.90); and BP (Grade 1, 0.77 and 0.73; Grade 3, 0.82 and 0.85; Grade 5, 0.80 and 0.72).
For the child BPI, 7 items tapped Overt Aggression (e.g., “I fight with other kids a lot/I don’t fight with other kids a lot”), 6 items tapped Relational Aggression (e.g., “If I don’t like a kid, I say bad things about them to my friends/If I don’t like a kid I don’t say bad things about them to my friends”), and 4 items tapped Bullied by Peers (e.g., “Kids at school pick on me/Kids at school don’t pick on me”). During the BPI, two dog hand puppets presented opposing positive and negative statements and children indicated which puppet was more like them. Responses were videotaped and coded on a 6-point scale based on whether the child selected a positive or negative statement and whether the response was a straight endorsement (5 if positive, 2 if negative), amplification (6 if positive, 1 if negative), qualification (4 if positive, 3 if negative), or unqualified, “both” (3.5). On the HBQ-C, completed at Grades 3 and 5, 7 and 8 items, respectively, tapped Overt Aggression; 6 items tapped Relational Aggression; and 4 and 5 items, respectively, tapped Bullied by Peers. Children chose the one statement from each pair that was most like them and then marked that statement as being “sort of like me,” “mostly like me,” or “really like me.” These responses were coded on a 6-point scale based on which statement the child selected (positive or negative) and whether the response was “really like me” (6 if positive, 1 if negative), “mostly like me” (5 if positive, 2 if negative), or “sort of like me” (4 if positive, 3 if negative). Overall child-report α coefficients were acceptable for each scale at each time point: OA (Grade 1 = 0.82; Grade 3 = 0.81; Grade 5 = 0.82); RA (Grade 1 = 0.67; Grade 3 = 0.80; Grade 5 = 0.78); and BP (Grade 1 = 0.73; Grade 3 = 0.87; Grade 5 = 0.89).
Separately for OA, RA, and BP, multi-informant scores were computed using the PCA-based approach outlined by Kraemer and colleagues (2003)
, which by carefully selecting reporters who view the child from different perspectives (e.g., child self-view vs. adult view) and in different contexts (e.g., home vs. school) can be used to measure a core characteristic (e.g., behavioral symptoms) that is free of systematic error associated with reporters’ different perspectives and contexts. The resulting first component of each PCA (designated the core scores for OA, RA, and BP) represented the variance in reported symptoms shared among the three reports (see (Kraemer et al., 2003
) for details). The resulting HBQ OA multi-informant scores accounted for 47% (Grade 1), 52% (Grade 3), and 56% (Grade 5) of the total variance, respectively. HBQ RA multi-informant scores accounted for 47% (Grade 1), 48% (Grade 3), and 48% (Grade 5) of the total variance, respectively. HBQ BP multi-informant scores accounted for 48% (Grade 1), 56% (Grade 3), and 56% (Grade 5) of the total variance.
Due to budget constraints at the Grade 1 assessment, only three-quarters of participating children completed the BPI; all mothers and teachers completed the HBQ. Because of this, aggression and victimization multi-informant scores were not available for many children who did participate fully at later assessment times. To retain the largest possible sample, missing core scores were replaced with alternate scores calculated by PCA of mother-teacher (MT), mother-child (MC), and child-teacher (CT) reports at Grades 1, 3, and 5. The use of unrotated PCA reduces the number of predictors and the risk of multicolinearity in predictive models by transforming correlated variables into fewer, uncorrelated principal components. The first component accounts for the majority of variability, exhibits greater variability than a simple average, and is retained as the best representation of the construct (Dunteman, 1989
These alternate scores correlated highly with the multi-informant scores (MTC): Overt Aggression (all rs 0.85 – 0.95); Relational Aggression (all rs 0.86 – 0.92); Bullied by Peers (all rs 0.87–0.93). Missing scores were replaced with the available alternate score: OA (Grade 1 240-MTC, 95-MT, 9-MC, 0-CT; Grade 3 328-MTC, 5-MT, 11-MC, 0-CT; Grade 5 321-MTC, 3-MT, 20-MC, 0-CT); RA (Grade 1 236-MTC, 97-MT, 11-MC, 0-CT; Grade 3 328-MTC, 5-MT, 11-MC, 0-CT; Grade 5 321-MTC, 3-MT, 20-MC, 0-CT); BP (Grade 1 240-MTC, 95-MT, 9-MC, 0-CT; Grade 3 328-MTC, 5-MT, 11-MC, 0-CT; Grade 5 321-MTC, 3-MT, 20-MC, 0-CT).
These peer aggression and victimization scores were used to define aggressor/victim subgroup status. A 33% cut-point was selected because it was used in the original study (Burk et al., 2008
) and in other studies of aggressive victims (Haynie et al., 2001
; Schwartz, 2000
). Because we aimed to track whether previously identified aggressor/victim subgroups maintained that status, the same categorization scheme was utilized at Grade 3 and 5. This approach also yielded subgroups of sufficient size for comparative analyses. To check the robustness of our results, analyses were conducted using cut-points of 25% and 16% (1SD
); no differences in the pattern of results were obtained (analyses not shown). Children were defined as Aggressive Victims if they were in the upper 33% for Overt or Relational Aggression and Bullied by Peers; Aggressors if they were in the upper 33% for Overt or Relational Aggression but not Bullied by Peers; and Victims if they were in the upper 33% for Bullied by Peers but not Overt or Relational Aggression. Children in the lower 67% for all 3 scales were defined as Socially Adjusted. The resulting group composition follows: Grade 1
- 75 Aggressive Victims (AV; 35 girls; 40 boys), 83 Aggressors (AG; 38 girls; 45 boys), 39 Victims (VI; 24 girls; 15 boys), and 147 Socially Adjusted (SA; 83 girls; 64 boys); Grade 3
- 77 AV (36 girls; 41 boys), 84 AG (43 girls; 41 boys), 37 VI (13 girls; 24 boys), and 146 SA (88 girls; 58 boys); Grade 5
- 75 AV (34 girls; 41 boys), 80 AG (37 girls; 43 boys), 39 VI (19 girls; 20 boys), and 150 SA (90 girls; 60 boys).
Mental Health, School, Physical Health, and Service Use Outcomes
Children’s mental and physical health symptoms, and school problems were assessed using mother, teacher and child HBQ scales from Grades 5, 7, and 9. For Internalizing Symptoms mothers and teachers rated 16 (Grades 5 and 7), or 18 items (Grade 9) measuring Depression (e.g., “Cries a lot”); 11 (Grade 5), 12 (Grade 7), or 14 items (Grade 9) measuring Generalized Anxiety (e.g., “Worries about things in the future”). For Externalizing Symptoms mothers and teachers rated 9 items (Grades 5, 7, and 9) measuring Oppositional Defiant Disorder (e.g., “Argues a lot with adults”) and 15 (Grade 5) or 14 items (Grades 7 and 9) measuring Conduct Disorder (e.g., “Lies or cheats”). Mothers and teachers rated 6 (Grade 5), 7 (Grade 7), or 9 items (Grade 9) measuring Inattention (e.g., “Does not seem to listen”), and 9 items (Grades 5, 7, and 9) measuring Impulsivity (e.g., “Interrupts or butts in on others”). All mental health items were rated on a 3-point scale ranging from 0 (never or not true) to 2 (often or very true). For Academic Competence, mothers rated 6 items (e.g., “How good would you say your child is in reading”) at Grades 5, 7 and 9 on a 5-point scale ranging from 1 (poor) to 5 (excellent). At Grades 5, 7, and 9 teachers rated 5 items (e.g., “How would you rate this child’s current performance in reading”) on a 5-point scale ranging from 1 (not well at all, poor student) to 5 (very well, excellent student). For School Engagement mothers rated 8 items (e.g., “Currently, how much is your child excited about school”) on a 4-point scale ranging from 1 (not at all) to 4 (quite a bit). Teachers rated 8 items (e.g., “Is interested and engaged in classroom activities”) on a 3-point scale ranging from 0 (does not apply) to 2 (certainly applies). For global physical health problems, mothers and teachers rated 5 items (e.g., “In general would you say this child’s physical health is excellent, good, fair, or poor?”) on a 4-point scale ranging from 1 (excellent) to 4 (poor).
For the HBQ-C participating children completed 30 (Grade 5), 34 (Grade 7), or 38 items (Grade 9) for Internalizing Symptoms (e.g., “I worry about things I’ve done/I don’t worry about things I’ve done”); 20 (Grade 5) or 22 items (Grades 7 and 9) for Externalizing Symptoms (e.g., “I do what adults ask me to do/I don’t do what adults ask me to do”); and 12 (Grade 5), 15 (Grade 7), or 17 items (Grade 9) tapping Attention and Impulsivity (e.g., “I have a hard time paying attention/I don’t have a hard time paying attention”). Children rated 12 items for Academic Competence at Grades 5, 7, and 9 (e.g., “Schoolwork is easy for me/Schoolwork is not easy for me,”) and 11 (Grade 5) or 10 items (Grades 7 and 9) for School Engagement (e.g., “I like school/I don’t like school”). For Global Physical Health Problems children rated 6 item pairs (e.g., “I’m a healthy teen/I’m not a healthy teen”). Children rated each item using the previously described HBQ-C scale. Coefficients α for mental health, physical health, and school problems subscale scores ranged from 0.70 to 0.96 for all reporters across all assessments.
Multi-informant core-scores were created for each construct at each grade using the procedures outlined above (Kraemer et al., 2003
). The resulting scores for Internalizing Symptoms, Externalizing Symptoms, Inattention/Impulsivity, Academic Competence, School Engagement, and Global Physical Health Problems accounted for 50% to 76% of the total variance at Grades 5, 7, and 9. To facilitate repeated measures analysis, missing multi-informant scores were replaced with alternate scores as described above. Alternate scores were highly correlated with multi-informant scores: Internalizing (all r
s 0.87–0.93); Externalizing (all r
s 0.89–0.93); Inattention/Impulsivity (all r
s 0.92–0.94), Academic Competence (all r
s 0.96–0.97); School Engagement (all r
s 0.92–0.93); Global Physical Health Problems (all r
s 0.90–0.93). Final scores were as follows: Grade 5
321-MTC, 3-MT, 20-MC, 0-CT; Grade 7
305-MTC, 18-MC, 4-CT, 16-missing; Grade 9
287-MTC, 4-MT, 21-MC, 6-CT, 26-missing.
Using maternal reports of child height and weight, children’s raw BMI was calculated at Grades 5, 7, and 9. Raw BMI scores were standardized for gender and age against U.S. norms (Ogden et al., 2002
) before inclusion in analysis. To ascertain use of health services, mothers reported on the number of school-based behavioral and academic services received, the number of medications used for physical or mental health problems, and if the child attended psychotherapy. One point was assigned for any use of school services, one point for any medication use, and one point for any use of psychotherapy. Points were summed as a Total Service Use score ranging from 0 to 3, and standardized as a z-score. Three hundred fifteen cases (91.6%) were available for the analysis of Internalizing, Externalizing, Inattention/Impulsivity, Academic Competence, and School Engagement. Two hundred seventy nine cases (81.1%) were available for the analysis of BMI, Global Physical Health Problems, and Total Service Use.