Abstract
Research on adolescent aggression often distinguishes between reactive and proactive aggression, but there is limited knowledge regarding the application or measurement of these subtypes of aggression among female youth, especially forensic samples of female youth. Drawing on 377 girls (103 selected from forensic settings and 274 selected from school settings) from Portugal, the current study is the first to simultaneously examine the psychometric properties of the Reactive-Proactive Aggression Questionnaire (RPQ) in incarcerated girls and community girls. The results support the use of the RPQ in terms of its two-factor structure, measurement invariance, internal consistency, convergent validity, discriminant validity, and known-groups validity. Significant associations were found with several criterion-related variables such as age of criminal onset, age of first problem with the law, conduct disorder, crime severity, violent crimes, and alcohol and drug use. Findings are discussed in terms of the use of the RPQ among incarcerated girls and community girls.
Aggression can be characterized as a heterogeneous construct with proactive and reactive aggression as two commonly referenced subtypes of aggression (Dodge, 1991; Dodge & Coie, 1987). While closely related (e.g., Dodge & Coie, 1987), proactive and reactive aggression can be distinguished based on the underlying motivation behind the aggressive act (see Merk, de Castro, Koops, & Matthys, 2005, for a review). Proactive aggression is planned and unprovoked aggression that is motivated by secondary goals such as dominance or instrumental gain, whereas reactive aggression is impulsive or unplanned, and occurs as a response to a perceived or actual threat or insult (Chase, O’Leary, & Heyman, 2001; Dodge, Lochman, Harnish, Bates, & Pettit, 1997). Although recognized as distinct subtypes of aggression, proactive and reactive aggression often coexist and contribute to an individual’s overall level of aggression (Rosell & Siever, 2015).
Despite questions regarding its utility (Bushman & Anderson, 2001), the reactive and proactive distinction remains prominent among scholars, and theories have been developed to explain the distinct causal pathways leading to each form (see Kempes, Matthys, de Vries, & van Engeland, 2005, for a review). Specifically, Crick and Dodge (1996) theorized that disruptions in social-information processing can lead to both reactive and proactive aggression depending on the distinct developmental stage that the disruption occurs. Further solidifying reactive and proactive aggression as separate dimensions of aggression, empirical research has identified unique neurobiological (Bass & Nussbaum, 2010; Levi, Nussbaum, & Rich, 2010; Urheim et al., 2014) and environmental (Brendgen, Vitaro, Boivin, Dionne, & Pérusse, 2006) etiological factors underpinning each of them. For instance, proactive and reactive aggression differ with regard to their underlying emotional processing. That is, proactive aggression has demonstrated associations with affective deficits such as reduced skin conductance and heart rate (Hubbard et al., 2002), while reactive aggression has been linked to poor emotion regulation and low frustration tolerance (Vitaro, Brendgen, & Tremblay, 2002). Likewise, a number of studies have identified external correlates that are unique to these two subtypes of aggression (e.g., Ang, Huan, & Florell, 2014). For example, unlike proactive aggression, reactive aggression tends to show positive associations with emotional dysregulation and internalizing problems such as anxiety and depression (Fite, Stoppelbein, & Greening, 2009). Conversely, proactive aggression tends to be associated with externalizing or antisocial behavior and traits associated with psychopathy (Card & Little, 2006; Cima & Raine, 2009; Fite et al., 2009).
Stability estimates of these two subtypes of aggression also support separate developmental trajectories. For instance, longitudinal research using a twin sample supports separate developmental trajectories for these two subtypes of aggression that differ with regard to stability. Specifically, Tuvblad, Raine, Zheng, and Baker (2009) found that reactive aggression decreased with age, whereas proactive aggression remained relatively stable from childhood into adolescence for both sexes (Tuvblad et al., 2009). However, another study using a large, nontwin sample of youth found that proactive aggression actually increased for boys across adolescence but seemed to remain relatively stable for girls (Fung, Raine, & Gao, 2009). In examining genetic and environmental influences of aggression, the stability in reactive aggression is thought to be the result of both genetic and nonshared environments, whereas stability in proactive aggression is primarily attributed to genetic influences (Tuvblad et al., 2009). Other research in twin samples has found that genetic influences are involved in proactive and reactive aggression for boys, but shared and nonshared environmental influences account for both subtypes of aggression in girls (Baker, Raine, Liu, & Jacobson, 2008). Taken together, both empirical and theoretical evidence support the distinction between these two subtypes of aggression. In addition, this distinction could have important implications for identification and treatment of aggression and antisocial outcomes (Barker et al., 2010) that could differ depending on gender. Therefore, it is imperative that reliable and valid measures are constructed and tested that capture this heterogeneity.
Although various methods for assessing aggression exist, the Reactive-Proactive Aggression Questionnaire (RPQ) is a well-validated and widely used measure that captures both subtypes (Raine et al., 2006). For instance, internal reliability of the RPQ has been substantiated across various samples (Borroni, Somma, Andershed, Maffei, & Fossati, 2014; Cima & Raine, 2009; Raine et al., 2006; Seals, Sharp, Ha, & Michonski, 2012), and results from factor analyses provide consistent support for the two-factor structure of the RPQ (e.g., Baker et al., 2008; Raine et al., 2006). Likewise, the two dimensions of the RPQ have shown distinct associations with external criteria. For example, unlike the Reactive scale, the Proactive scale demonstrates associations with externalizing behaviors such as serious delinquency and initiating fights (Raine et al., 2006), as well as substance use and engaging in risky sex (Miller & Lynam, 2006). The Proactive scale of the RPQ is also positively related to measures of psychopathy, while the Reactive subscale tends to be unrelated to such measures (Cima & Raine, 2009; Raine et al., 2006; Seals et al., 2012; van Baardewijk, Vermeiren, Stegge, & Doreleijers, 2011). In addition, while both the reactive and proactive aggression scales of the RPQ are positively related to narcissism, the Proactive scale shows stronger, positive associations compared with the Reactive scale (Ang & Raine, 2009; Seah & Ang, 2008).
In sum, the RPQ demonstrates good construct validity and external validity. However, research is limited, in that the RPQ has primarily been validated among community samples of adolescent boys or mixed gender samples. Thus, few studies have examined the construct validity of the RPQ among adolescent girls, especially detained adolescent girls. Using a different measure of aggression, research by Marsee and Frick (2007) found that poor emotion regulation was uniquely associated with reactive aggression, while callous-unemotional (CU) traits and positive outcome expectations were associated with proactive aggression among a sample of detained female adolescents. Similar associations have also been detected in samples of children (e.g., Dodge et al., 1997; Vitaro, Barker, Boivin, Brendgen, & Tremblay, 2006), and together this research is consistent with Dodge’s social-information processing model (Crick & Dodge, 1996). More recently, among a sample of detained female adolescents, it was found that levels of proactive aggression were higher among those with both conduct disorder and elevated levels of CU traits compared with those with conduct disorder alone (van Damme, Colins, & Vanderplasschen, 2016).
Overall, several constructs (e.g., psychopathy, narcissism, impulsivity, substance use, and internalizing symptoms) demonstrate divergent associations with regard to the aggression subtypes, and may shed further light on the distinction between reactive and proactive aggression in adolescent girls. However, few studies have examined unique associations between proactive and reactive aggression as captured by the RPQ, and important constructs such as anxiety and empathy. It may be particularly important to examine how these associations manifest among girls, given differences in onset of aggression in girls relative to boys (e.g., Moffitt, Caspi, Rutter, & Silva, 2001) and the increasing rates of aggression and violence among adolescent girls over the last two decades (Moretti, Catchpole, & Odgers, 2005).
Sex Differences in Aggression
Extant research shows that starting at the age of 4, boys are overall more aggressive than girls, both physically and verbally (see Archer [2004] for a review). These gender differences remain stable during childhood and adolescence with girls being 2 to 4 times less likely to develop aggressive behavior problems or receive a diagnosis of conduct disorder (Prior, Smart, Sanson, & Oberklaid, 1993). In contrast, evidence for sex differences in reactive and proactive aggression is equivocal. Results from some studies have concluded that sex differences do exist (e.g., Fossati et al., 2009), while others report no differences between boys and girls in proactive or reactive aggression (e.g., Raine, Fung, Portnoy, Choy, & Spring, 2014). For instance, in a community sample of children and adolescents aged 6 to 12, Kempes, Matthys, Maassen, van Goozen, and van Engeland (2006) found no differences in parent report of proactive aggression, but parents rated boys significantly higher on reactive aggression than girls (Kempes et al., 2006). Alternatively, among a community sample of Greek Cypriot adolescents aged 12 to 18, boys demonstrated higher rates of proactive aggression, but no differences were found between boys and girls in reactive aggression (Fanti, Frick, & Georgiou, 2009). Another study, utilizing a large community sample of Turkish children aged 9 to 14, found that boys scored higher on both proactive and reactive aggression scales compared with girls (Baş & Yurdabakan, 2012). Finally, among a sample of clinic-referred children and adolescents aged 5 to 18, no gender differences in parent reports of reactive or proactive aggression were found (Connor, Steingard, Anderson, & Melloni, 2003).
Despite the equivocal nature of relative sex differences in reactive and proactive aggression, no sex differences have been found in the factor structure of the RPQ across various age ranges (e.g., Baker et al., 2008; Cima, Raine, Meesters, & Popma, 2013) and cultures (Fossati et al., 2009; Fung et al., 2009), suggesting that this instrument is appropriate for assessing aggression in both boys and girls. However, while past research has included small subsamples of detained female adolescents (e.g., Cima et al., 2013), no study to date has explicitly examined the psychometric properties of the RPQ in a sample of detained female adolescents, nor have the psychometric properties of the RPQ been compared across different settings (i.e., forensic vs. school).
Given the gender differences in aggression observed in prior research, it is important that research examines the psychometric properties of the RPQ among certain groups (i.e., females) and across different settings (i.e., forensic and school). Such research can help determine the appropriateness of using the RPQ to assess aggression among certain populations as well as whether findings from research utilizing the RPQ based on samples of other groups generalize to girls, particularly detained girls. Despite the importance of such research evaluating the RPQ, few studies exist that have evaluated the RPQ among this particular group (i.e., detained adolescent girls).
Current Study
The current study attempts to address some of the gaps in the literature regarding the RPQ and its subscales in several ways. First, the main goal of the current study is to validate the RPQ among a detained sample of female Portuguese youth. This sample provides a unique context for validating the RPQ and examining distinctions between reactive and proactive aggression more generally. Cultural differences in the socialization of youth and differences in developmentally appropriate behavioral norms, particularly gender differences, may lead to measurement differences in aggression between boys and girls (e.g., Bergeron & Schneider, 2005). Thus, the psychometric properties including internal consistency, factor structure, and convergent and criterion-related validity of the RPQ among a unique sample of detained Portuguese girls will be examined. Specifically, the current study examines distinct associations between the Reactive and Proactive scales with theoretically relevant criteria (e.g., psychopathic personality traits, narcissism, conduct disorder, age at first arrest, crime severity, physical violence, and substance use). In addition, this study attempts to fill a gap in the literature by examining the distinct associations between the Reactive and Proactive scales of the RPQ with empathy and anxiety.
It was hypothesized that (a) the original two-factor structure would best fit the RPQ using confirmatory factor analytic methods, and would show measurement invariance and good internal consistency; (b) the RPQ would exhibit expected associations with theoretically relevant outcomes used to assess aspects of convergent validity (e.g., psychopathic traits, impulsivity) and discriminant validity (i.e., empathy, anxiety); (c) the RPQ scores would be positively associated with relevant variables used to assess aspects of criterion validity, such as conduct disorder, age of crime onset, age of first problem with the law, increased crime severity, use of physical violence, alcohol abuse, and drug use; and (d) the RPQ would show known-groups validity, with the forensic sample obtaining higher scores than the school sample.
Method
Participants
The sample was comprised of 377 girls (N = 377; Mage = 16.23 years; SD = 1.38 years; range = 14-19 years) recruited in forensic and school contexts. Of this total, 103 participants (Mage = 16.41 years; SD = 1.19 years; range = 14-18 years) formed the forensic sample, and 274 participants (Mage = 16.17 years; SD = 1.44 years; range = 14-19 years) formed the school sample. The school sample was recruited from public schools of the Lisbon, Algarve, and Coimbra regions. The forensic sample was recruited from three juvenile detention centers managed by the Portuguese Ministry of Justice that admit female detainees. They were all detained by the court’s decision, the harshest sentence the court can give to teenagers. Among the detained girls, the mean age of crime onset was 12.50 years (SD = 1.56), and mean age of first criminal problems with the law was 13.27 years (SD = 1.55). Most were detained before they were 16 years old (M = 15.90, SD = 1.04) as a result of committing serious and violent crimes (e.g., robbery, assault).
The participants were mainly White Europeans (forensic sample = 59.2%; school sample = 90.1%) from an urban background (forensic sample = 97.1%; school sample = 100%) with a low socioeconomic status (SES; forensic sample = 60.2%; school sample = 39.1%). No significant differences were found between the two samples in terms of age (F = 2.265, p = .133). Significant differences were found regarding years of education (F = 275.577, p ≤ .001) with the school sample having more years of education (M = 9.17 years; SD = 1.26) than the forensic sample (M = 6.66 years; SD = 1.42). Significant differences were also found regarding ethnicity (χ2 = 47,872, p ≤ .001), urban versus rural background (χ2 = 8.045; p ≤ .05), and SES (U = 10,407.00; p ≤ .001).
Measures
The RPQ (Raine et al., 2006) is a self-report measure that was designed to distinguish between reactive and proactive aggression. The RPQ consists of 23 items rated on a 3-point ordinal scale (never = 0, sometimes = 1, often = 2). A total of 11 items assess reactive aggression (e.g., “Reacted angrily when provoked by others”) and 12 items assess proactive aggression (e.g., “Hurt others to win a game”). Summed scores provide a measure of reactive or proactive aggression, as well as total aggression. Higher scores indicate higher levels of aggression. The RPQ has been validated in samples of children (Baker et al., 2008), adolescents (Raine et al., 2006), and young adults (Cima et al., 2013). Internal consistency for adolescents has previously been reported as α = .86 for proactive aggression, α = .84 for reactive aggression, and α = .90 for total aggression (Raine et al., 2006). The Portuguese version of the RPQ was used (Pechorro, Ray, Raine, Marôco, & Gonçalves, 2015). Internal consistency reliability statistics for the RPQ in the current sample are presented below.
The Antisocial Process Screening Device–Self-Report (APSD-SR; Frick & Hare, 2001; Muñoz & Frick, 2007) is a multidimensional 20-item measure designed to assess psychopathic traits in adolescents. It was modeled after the Psychopathy Checklist–Revised (PCL-R; Hare, 2003). Each item is scored on a 3-point ordinal scale (never = 0, sometimes = 1, often = 2). The total score, as well as each dimension score, is obtained by adding the respective items. Some studies (e.g., Frick, O’Brien, Wootton, & McBurnett, 1994) reported two main factors (callous-unemotional and impulsivity/conduct problems), while others (e.g., Frick, Barry, & Bodin, 2000) reported three main factors: callous-unemotional, narcissism, and impulsivity. Higher scores are indicative of an increased presence of psychopathic traits. The Portuguese validation of the APSD-SR was used (Pechorro, Hidalgo, Nunes, & Jiménez, 2016; Pechorro, Marôco, Poiares, & Vieira, 2013). The internal consistency for the current study was α = .77.
The Youth Psychopathic Traits Inventory (YPI; H. Andershed, Kerr, Stattin, & Levander, 2002) is a 50-item self-report measure designed to assess the core personality traits of the psychopathic personality constellation in youth aged 12 years and older. Each item is scored on an ordinal 4-point Likert-type scale (ranging from does not apply at all = 1 to applies very well = 4). The YPI consists of 10 subscales (with five items each) designed in line with Cooke and Michie’s (2001) three-dimensional conceptualization of the psychopathy construct, namely, the Grandiose-Manipulative dimension, the Callous-Unemotional dimension, and the Impulsive-Irresponsible dimension. More specifically, the Grandiose-Manipulative dimension consists of the Dishonest Charm, Grandiosity, Lying, and Manipulation subscales; the Callous-Unemotional dimension consists of the Callousness, Unemotionality, and Remorselessness subscales; and the Impulsive-Irresponsible dimension consists of the Impulsivity, Thrill-seeking, and Irresponsibility subscales. Higher scores reflect an increased presence of psychopathic traits. The Portuguese version of the YPI was used (Pechorro, Andershed, Ray, Marôco, & Gonçalves, 2015; Pechorro, Ribeiro da Silva, Andershed, Rijo, & Gonçalves, 2016). The internal consistency for the current study was α = .94.
The Inventory of Callous-Unemotional Traits (ICU; Essau, Sasagawa, & Frick, 2006; Kimonis et al., 2008) is a 24-item self-report scale designed to assess callous and unemotional (CU) traits in youth derived from the Callous-Unemotional subscale of the Antisocial Process Screening Device (APSD; Frick & Hare, 2001). Each item is scored on a 4-point scale (ranging from not at all true = 0 to definitely true = 3). Scores are calculated by reverse scoring the positively worded items, and then summing the items to obtain a total score. Prior research has identified three independent factors: callousness, unemotional, and uncaring (e.g., Kimonis et al., 2008). All items also loaded onto a general callous-unemotional factor. Higher scores are indicative of increased CU traits. The Portuguese validation of the ICU was used (Pechorro, Hawes, Gonçalves, & Ray, 2016; Pechorro, Ray, Barroso, Marôco, & Gonçalves, 2016). The internal consistency for the total score of the ICU in the current study was α = .86.
The Narcissistic Personality Inventory-13 (NPI-13; Gentile et al., 2013) is a short form of the widely used Narcissistic Personality Inventory (NPI; Raskin & Terry, 1988). The NPI-13 consists of 13 pairs of statements where one of each pair is indicative of narcissism and the other is not (coded 1 or 0, respectively). Respondents are asked to select the one that they most agree with. The NPI-13 provides both a total score and three subscale scores: Leadership/Authority, Grandiose Exhibitionism, and Entitlement/Exploitativeness. Higher scores represent an increased presence of narcissistic personality traits. The Portuguese version of the NPI-13, especially adapted for use with adolescents, was used (Pechorro, Gentile, Ray, Nunes, & Gonçalves, 2016). The internal consistency for the current study, estimated by Kuder–Richardson coefficient (i.e., α for dichotomous items), was .82.
The Barratt Impulsiveness Scale version 11 (B1S-11; Patton, Stanford, & Barratt, 1995; Stanford et al., 2009) is a 30-item self-report questionnaire designed to measure impulsiveness. Each item is scored on a 4-point ordinal scale (ranging from rarely/never = 1 to almost always/always = 4). The BIS-11 contains six subscales, which correspond to the six first-order factors: (a) attention, (b) cognitive instability, (c) motor, (d) perseverance, (e) self-control, and (f) cognitive complexity. These six first-order factors converge into three second-order factors, namely, (a) attentional impulsiveness (Attention and Cognitive Instability dimensions), (b) motor impulsiveness (Motor and Perseverance dimensions), and (c) nonplanning impulsiveness (Self-Control and Cognitive Complexity dimensions). The total score, as well as each dimension score, is obtained by adding the respective items. Higher scores on the BIS-11 reflect higher levels of impulsiveness. A Portuguese version of the BIS-11, especially adapted for use with adolescents, was used (Pechorro, Ayala-Nunes, Nunes, Maia, & Gonçalves, 2016; Pechorro, Ayala-Nunes, Ray, Nunes, & Gonçalves, 2016; Pechorro, Marôco, Ray, & Gonçalves, 2015). The internal consistency for the current study was α = .85.
The Basic Empathy Scale (BES; Jolliffe & Farrington, 2006) is a 20-item self-report measure designed to assess empathy in youth. The BES was developed as a concise and coherent scale with the aim of measuring two distinct factors: affective empathy and cognitive empathy. Each item is scored on a 5-point ordinal scale (ranging from strongly disagree = 1 to strongly agree = 5). Scores are calculated by reverse scoring the positively worded items, and then summing the items to obtain the total score and the factor scores. Higher scores indicate an increased presence of the associated characteristics. The Portuguese version of the BES was used (Pechorro, Ray, Salas-Wright, Marôco, & Gonçalves, 2015). The internal consistency for the current study was α = .88.
The Social Anxiety Scale for Adolescents (SAS-A; La Greca & Lopez, 1998) is an 18-item self-report scale designed to assess subjective experience of social anxiety in adolescents. Each item is rated on a 5-point scale (ranging from not at all = 1 to all the time = 5). Three distinct subscales have been identified: the Fear of Negative Evaluation (FNE) subscale reflects fears, concerns, or worries regarding negative evaluations from peers; the Social Avoidance and Distress–New (SAD-New) subscale reflects social avoidance and distress with new social situations or unfamiliar peers; the Social Avoidance and Distress–General (SAD-General) subscale reflects more generalized or pervasive social distress, discomfort, and inhibition. Scores are obtained by summing the ratings for the items comprising each subscale. The Portuguese validation of the SAS-A was used (Pechorro, Ayala-Nunes, Nunes, Marôco, & Gonçalves, 2016). Internal consistency for the present study was α = .93.
The Sellin-Wolfgang Index of Crime Seriousness (ICS; Wolfgang et al., as cited in White et al., 1994) guided the delinquency seriousness classification of the official court reports. Level 0 consists of no delinquency. Level 1 consists of minor delinquency committed at home such as stealing small amounts of money from mother’s purse. Level 2 consists of minor delinquency outside the home, including shoplifting something worth less than 5 euros, vandalism, and minor fraud (e.g., not paying bus fare). Level 3 consists of moderately serious delinquency such as any theft more than 5 euros, gang fighting, carrying weapons, and joyriding. Level 4 consists of serious delinquency such as car theft and breaking and entering. Level 5 consists of having performed at least two of each of the behaviors in the previous level.
A Conduct Disorder (CD) scale was also created based on the 15 items used to assess CD (see, for example, Skilling, Quinsey, & Craig, 2001). The 15 dichotomous items (coded no = 0, yes = 1) were summated to obtain a total continuous score. Thus, higher scores indicate a higher number of positively endorsed indicators of CD. Based on the Kuder–Richardson coefficient, the internal consistency of the CD scale was .89.
In addition, a questionnaire was constructed to describe the sociodemographic and criminal characteristics of the participants. This questionnaire included variables such as participants’ age, ethnic group, geographic classification of residence (rural vs. urban), level of schooling completed, SES, parental marital status, previous use of physical violence (coded no = 0, yes = 1), alcohol abuse, and cannabis use (these last two coded as 5-point ordinal scales from almost never/never = 0 to almost always/always = 4). SES was measured by considering both parental level of education and profession, appropriate to the Portuguese context. Diagnostic and Statistical Manual of Mental Disorders’ (5th ed.; DSM-5; American Psychiatric Association, 2013) Conduct Disorder diagnosis (CD) was assessed only for the forensic sample by the first and last authors of this article, using the official diagnostic criteria (i.e., the standard method described in the DSM-5). The prevalence of CD found in the current forensic sample (85.4%) was higher than those typically found among forensic samples composed of female youth (Sevecke & Kosson, 2010).
Procedure
Authorization to validate the RPQ in Portugal was obtained from the first author of the questionnaire (Raine et al., 2006). Appropriate procedures (e.g., avoiding item bias or differential item functioning) were followed during the translation and retroversion (Hambleton, Merenda, & Spielberger, 2005). The initial translation from English into Portuguese was completed by the first and last authors of this article, who made sure that young people would be able to properly understand the meaning of the items. The questionnaire was then independently translated back into English by a native English speaker with considerable professional experience in translating psychology-related scientific texts. No significant differences were found between the back-translation and the original version, demonstrating that the translated items had the same or very similar meanings as the original English items.
Authorization to assess detained youth was obtained from the General Directorate of Reintegration and Prison Services of the Portuguese Ministry of Justice (DGRSP-MJ). The detainees were informed about the nature of the study and asked to voluntarily participate. The participation rate was approximately 89%. Motives for not participating included refusal to participate (6%), inability to participate due to not understanding the Portuguese language (4%), and inability to participate due to security issues (1%). Authorization to assess youth in the school context was obtained from the General Directorate of Education of the Portuguese Ministry of Education (DGE-ME), and parental permission was obtained for all children. The participants, students from public schools of the Lisbon, Algarve, and Coimbra regions, were informed about the nature of the study and asked to voluntarily participate. The participation rate was approximately 84%. Participants who were unwilling or unable to collaborate were excluded.
All the participants were informed about the nature of the study and gave their informed consent for inclusion before they participated voluntarily. The research was approved by the Ethics Committees of the DGRSP-MJ (Code 122/DSPRE/2013) and DGE-ME (Code 0338400001). Parental permission was obtained for all underage children, and informed consent was obtained from participants who were 18 years of age. The measures were administered using individual face-to-face interviews in an appropriate setting (forensic sample) and in an appropriate classroom group setting (school sample) using a paper-and-pencil method for collecting the data. Some of the information (e.g., sociodemographic variables) was obtained from self-reports, and institutional files were also used to complement the information obtained (e.g., prior criminal activity and detentions).
Data Analysis
The data were analyzed using SPSS v22 (IBM SPSS, 2013) and EQS 6.2 (Bentler & Wu, 2008). The factor structure of the Portuguese language version of the RPQ was assessed using confirmatory factor analysis (CFA) performed in EQS 6.2 (Bentler & Wu, 2008; Byrne, 2006) with the robust estimation methods. Goodness-of-fit indices were calculated, including Satorra–Bentler chi-square/degrees of freedom, comparative fit index (CFI), incremental fit index (IFI), and root mean square error of approximation (RMSEA). A chi-square/degrees of freedom value <5 is considered acceptable, a value ≤2 is considered good, and = 1 very good (Marôco, 2014; West, Taylor, & Wu, 2012). A CFI ≥ .90 and RMSEA ≤ .08 indicate adequate fit, whereas a CFI ≥ .95 and RMSEA ≤ .06 indicate good model fit (Byrne, 2006). The incremental fit index, also known as Bollen’s IFI, is relatively insensitive to sample size; values that exceed .90 are regarded as acceptable.
The CFA was performed on the original scale items, and only items with standardized loading above 0.30 were retained because factor loadings are generally considered to be meaningful when they exceed that value (e.g., Crocker & Algina, 2008). No modification indexes were used to improve the measurement model. Polychoric correlations with robust methodologies were used to perform the CFA on the ordinal items because they provide more accurate estimates for the correlations between ordinal items than Pearson’s correlations (Byrne, 2006). Weak (metric) and strong (scalar) invariance were evaluated, and the S-Βχ2 difference test determined if the constraints significantly deteriorated the model (Millsap & Olivera-Aguilar, 2012). The SBDIFF program was used to perform this difference test (http://homepages.abdn.ac.uk/j.crawford/pages/dept/sbdiff.htm).
ANOVAs were used to compare scale variables, Mann–Whitney’s U test was used to compare ordinal variables, and the chi-square test was used to compare nominal variables. Pearson’s correlations were used to analyze associations between scale variables, and Spearman’s correlations were used to analyze associations between ordinal variables and scale variables (Leech, Barrett, & Morgan, 2015). Correlations were considered low if below .20, moderate if between .20 and .50, and high if above .50. Cronbach’s alphas (considered satisfactory if above .70), mean interitem correlations (MIICs; considered good if within the .15-.50 range), and corrected item-total correlation ranges (CITCRs; considered adequate if above .20) were used to assess reliability (Clark & Watson, 1995; Nunnally, & Bernstein, 1994).
Results
The first step in examining the psychometric properties of the Portuguese version of the RPQ among female youth was to attempt to replicate, using CFA, the different factor structures proposed for this instrument (Raine et al., 2006). The following goodness-of-fit indexes were obtained for the different CFA models using the total sample: one-factor model (S-Βχ2 / df = 2.81; IFI = .94; CFI = .94; RMSEA = .07 [.06-.08]; Akaike information criterion [AIC] = 186.99); two-factor first-order intercorrelated model (S-Bχ2 / df = 2.48; IFI = .96; CFI = .96; RMSEA = .06 [.06-.07]; AIC = 110.17); and two-factor second-order model (S-Bχ2 / df = 4.55; IFI = .75; CFI = .75; RMSEA = .10 [.09-.10]; AIC = 580.77). The strongest support in terms of goodness-of-fit indexes was found for the two-factor first-order intercorrelated model, which also presented the lowest AIC. Figure 1 shows the item loadings for the two-factor intercorrelated structure estimated with the Maximum Likelihood (ML) robust method using the total sample. All items had loadings above a minimum recommended value of 0.30 (Crocker & Algina, 2008), and thus, none were removed from the model. It is worth noting that Item 7, “Had temper tantrums,” had the lowest loading of 0.35.

RPQ Two-Factor Maximum Likelihood Robust Structure With Standardized Item Loadings
The next step was testing for measurement invariance among the school sample and the forensic sample using the two-factor first-order intercorrelated model, for which we were able to find strong support in terms of goodness-of-fit indexes (see Table 1). The standardized item loadings were all above 0.30. The ΔS-Bχ2 (df) values were statistically nonsignificant in the comparison of the nested models regarding weak invariance (factor loadings constrained) and strong invariance (factor loadings and factor covariances constrained). The ΔCFI between the models was below the .01 cutoff. This suggests that the constraints specified do hold and leads us to assume that the models do share equivalence across the two groups (Byrne, 2006).
Test for Invariance of the RPQ Goodness-of-Fit Statistics
Note. RPQ = Reactive-Proactive Aggression Questionnaire; S-Βχ2 (df) = Satorra–Bentler chi-square (degrees of freedom); CFI = robust comparative fit index; RMSEA = robust root mean square error of approximation; CI = confidence interval; ns = nonsignificant at the .05 level.
Table 2 displays the intercorrelations among the RPQ total and its dimensions, Cronbach’s alpha, MIIC, and CITCR. With regard to the intercorrelations between the Proactive and Reactive scales, the findings suggest that they are strongly correlated. In addition, the RPQ and its subscales evidenced good internal reliability across all three measures of internal consistency.
Pearson’s Correlations Matrix, Cronbach’s Alpha, Mean Interitem Correlation, and Corrected Item-Total Correlation Range
Note. RPQ = Reactive-Proactive Aggression Questionnaire; RPQ Rea = Reactive dimension; RPQ Pro = Proactive dimension; alpha = Cronbach’s alpha; MIIC = mean interitem correlation; CITCR = corrected item-total correlation range.
p < .001.
The convergent validity of the RPQ total and its dimensions with APSD-SR, YPI, ICU, and NPI is presented in Table 3. As shown in the table, the correlations were in the expected direction and were moderate to high in magnitude. Interestingly, once the RPQ Proactive scale is taken into account many of the correlations for the RPQ Reactive scale become nonsignificant. This only occurred among the forensic sample and was not the case in the school sample, however. Specifically, the correlations between the RPQ Reactive scale and the APSD-SR, YPI, ICU, and NPI-13 were no longer significant once the RPQ Proactive scale was taken into account. Alternatively, the positive correlations remained significant for the RPQ Proactive scale even when accounting for the RPQ Reactive scale. Table 4 also shows the correlations between the RPQ and the BES and the SAS-A. However, across all three samples none of the correlations were significant at the bivariate and partial levels.
Convergent Validity With the APSD-SR, YPI, ICU, and NPI, and Discriminant Validity With the BES and SAS-A
Note. APSD-SR = Antisocial Process Screening Device–Self-Report; YPI = Youth Psychopathic traits Inventory; ICU = Inventory of Callous-Unemotional Traits; NPI-13 = Narcissistic Personality Inventory 13 items short version; BES = Basic Empathy Scale; SAS-A = Social Anxiety Scale for Adolescents; RPQ = Reactive-Proactive Aggression Questionnaire; ns = nonsignificant; BIS-11 = Barratt Impulsiveness Scale-11. Partial correlations controlling for the remaining dimension of the RPQ are given in parentheses.
p < .05. **p < .01. ***p < .001.
Correlations and Partial Correlations With Criterion-Related Variables
Note. RPQ = Reactive-Proactive Aggression Questionnaire; CD = DSM-5 Conduct Disorder diagnosis; CD symptoms = CD symptoms scored as a scale; ns = nonsignificant; ACO = age of crime onset; AFPL = age of first problem with the law; ICS = Index of Crime Seriousness; PPV = previous physical violence. Partial correlations controlling for the remaining dimension of the RPQ are given in parentheses.
p < .05. **p < .01. ***p < .001.
The correlations of the RPQ and its dimensions with CD, age of crime onset, age of first problem with the law, crime seriousness, and use of physical violence are presented in Table 4. In general, the correlations for the RPQ total were in the expected directions; however, there were some discrepancies in the correlations across the two samples. For instance, the RPQ total was unrelated to cannabis use among the forensic sample, yet was positively related among the school sample. In addition, the RPQ was unrelated to age of crime onset, age of first problem with the law, and previous physical violence among the school sample, yet these correlations were significant for the forensic sample. It is also interesting that similar patterns in the correlations emerged for the RPQ Reactive and Proactive scales across the different samples. In addition, it appears that the RPQ Proactive scale has a much stronger association with these criteria given that the partial correlations remain significant for this scale, yet many of the partial correlations are nonsignificant for the RPQ Reactive scale, and this appears to be specific to the forensic sample.
Criterion validity using ANOVAs revealed that statistical significant differences were found when comparing the forensic sample and the school sample (see Table 5). Specifically, the forensic sample scored significantly higher on both proactive and reactive aggression compared with the school sample.
Descriptive Statistics and ANOVAs for the RPQ
Note. RPQ = Reactive-Proactive Aggression Questionnaire.
Discussion
The present study examined the psychometric properties of the RPQ among a sample of forensic and community adolescent girls. Results of the factor analysis confirmed cross-cultural generalizability and factor structure of the RPQ for these Portuguese girls. CFA suggested that the two-factor first-order intercorrelated model was the best-fitting model, which is consistent with prior research (e.g., Baker et al., 2008; Cima et al., 2013; Raine et al., 2006). Furthermore, strong measurement invariance was found among the forensic sample and the school sample, consistent with a recent study among Singaporean adolescents which provided empirical support for the invariance of the two-factor model of the RPQ across gender (Ang, Huan, Li, & Chang, 2016). In addition, because testing for measurement invariance is still not frequent, this study as a whole adds to the psychometric literature on the RPQ.
Within both samples of forensic and community adolescents, internal consistency was good for the two subscales and total RPQ score (Kaplan & Saccuzzo, 2013). Adequate homogeneity was present between the items with MIICs falling within the recommended value range of .15 to .50 (Clark, & Watson, 1995). In addition, while the CFA provided support for reactive and proactive subscales, the intercorrelations between the subscales were fairly strong for both the forensic and school samples (r = .59 and .70, respectively), suggesting that they commonly occur together within the same individual. As expected, the forensic sample scored significantly higher on both proactive and reactive aggression than the school sample. In addition, the effect sizes for these differences were much stronger for proactive aggression (η p 2 = .47) than for reactive aggression (η p 2 = .24). These findings suggest that the RPQ may be more sensitive to proactive aggression among more severe samples of adolescent girls. Of course, one possible explanation is that while both subtypes of aggression are more prevalent among forensic populations of girls, there is more variation in proactive aggression among this group. Given the higher levels of proactive aggression among adolescents with psychopathic traits, namely, CU traits, compared with antisocial youth without such traits (e.g., Frick, Ray, Thornton, & Kahn, 2014), the RPQ may be useful for identifying a particularly severe subgroup of antisocial youth.
Evidence of adequate convergent and discriminant validity (American Educational Research Association, American Psychological Association, & National Council for Measurement in Education, 2014) was present with the RPQ demonstrating the expected associations with external correlates in both the forensic and school samples. Specifically, the RPQ subscales of proactive and reactive aggression were significantly and positively associated with self-reported measures of psychopathy, CU traits, impulsivity, and narcissism in both the forensic and school samples, although many of the correlations with reactive aggression became nonsignificant after controlling for proactive aggression. No significant associations emerged between the RPQ subscales and self-reported measures of empathy (Vachon, Lynam, & Johnson, 2014) or anxiety (Pechorro, Ayala-Nunes, Nunes, Marôco, & Gonçalves, 2016) in either sample evidencing discriminant validity. Differential correlations emerged between the forensic and school sample on measures of criminal behavior and substance use. In particular, both proactive and reactive aggression were associated with number of CD symptoms, age of first criminal act, age of first encounter with the law, past physical violence, and more serious delinquency within the forensic sample of female adolescents. However, only proactive aggression was associated with CD and substance use (alcohol, cannabis use) among the forensic sample. In addition, it appears that much of the relationship between aggression and these criterion variables is due to the proactive component based on the partial correlations controlling for the other scale. Conversely, within the school sample, both proactive and reactive aggression were associated with CD, delinquency, and substance use. Thus, in forensic samples of female adolescents, proactive aggression correlates more strongly with other important indicators of antisocial behavior than reactive aggression. These findings lend support to notion that aggression is multifaceted consisting of a reactive and proactive component, given the unique associations with certain criteria.
The results should be considered within the context of some limitations. First, the current study relied almost entirely on self-report, which may have increased the possibility of shared method variance inflating associations between study variables. However, findings from the current study are relatively consistent with theoretical views and past empirical work on the RPQ, including studies that have used multiple reporters. Nevertheless, future research would benefit from utilizing multiple informants, including parent, teacher, and even peer reports. Second, the cross-sectional design and analyses in the current study do not allow us to infer causality in terms of the associations between aggression and other constructs measured. Given prospective research in boys has shown proactive aggression, compared with reactive aggression is associated with more severe long-term outcomes (Fite, Raine, Stouthamer-Loeber, Loeber, & Pardini, 2010), this type of research is especially important to pursue in female populations. In addition, the cross-sectional nature of the current study does not allow for the examination of temporal stability, analysis of test–retest, or associated outcomes for the RPQ. While previous research that included female participants has revealed adequate temporal stability over a 3-year period (e.g., Cima et al., 2013), this study had only a small sample of girls, and thus, future research is warranted to examine these psychometric properties of the RPQ among detained female populations. In addition, the sample on which the current study was based consists only of girls. Directly comparing the utility of the RPQ between girls and boys is a necessary step for further validation of the RPQ.
Understanding how and why girls engage in aggressive behavior has remained somewhat elusive due to a focus on aggression in boys. Yet, we know that individuals who demonstrate high levels of aggression in childhood (both boys and girls) tend to demonstrate stable patterns of aggression (e.g., Bongers, Koot, van der Ende, & Verhulst, 2004; Côté, Vaillancourt, LeBlanc, Nagin, & Tremblay, 2006) and antisocial behavior through adolescence and adulthood (A. K. Andershed & Pepler, 2013; Farrington & Loeber, 2000; Nagin & Tremblay, 1999). Over time, continued engagement in aggressive and antisocial behavior has both individual and societal consequences among female adolescents, including higher mortality rates, less stable employment, psychiatric difficulties, and higher utilization of social service programs (Pajer, 1998). Given the distinct correlates of proactive and reactive aggression, identifying and distinguishing between these subtypes of aggression may provide further insight for treatment or intervention efforts (Merk, et al., 2005).
Footnotes
Acknowledgements
We wish to thank the following Portuguese juvenile detention centers for their collaboration: Bela Vista, Navarro de Paiva, and Santa Clara.
Results regarding alternative models are available upon request from the corresponding author.
This study was conducted at Psychology Research Centre, University of Minho, supported by the Portuguese Foundation for Science and Technology (FCT; Grant SFRH/BPD/86666/2012) with cofinancing of the European Social Fund (POPH/FSE), the Portuguese Ministry of Education and Science, and Fundo Europeu de Desenvolvimento Regional (FEDER) under the PT2020 Partnership Agreement (UID/PSI/01662/2013).
