Effect of physical activity interventions on aggressive behaviors for children and adolescents: A systematic review and meta-analysis
Introduction
Aggression is common and frequent among children and adolescents. Nearly 40 % of primary and secondary students experienced various forms of aggressive behaviors, such as taunting, harassment, or bullying at schools (Hellström et al., 2021; Hoffman, 2011; Liu & Graves, 2011), and 25 % of adolescents had aggressive behaviors to others (Zhang et al., 2012). Previous studies found that adolescents with high levels of aggression had increased risks of mental disorders, non-suicidal self-injury, suicide, and negative social relationships (Smokowski et al., 2013; Zhang et al., 2012). Aggression also can affect their education and may predispose them to later criminal behavior (World Health Organization, 2019). Children who are victims of aggression are also at increased risk for depression, sadness or loneliness, anxiety, injuries, school absenteeism and health complaints (Children's Safety Network, 2018). As the Children's Safety Network reported, such outcomes of aggression among children and adolescents have enacted a considerable social and economic toll. The direct and indirect economic costs of child and adolescent aggression exceed $158 billion per year to reform related policies, provide training and technical assistance to public health and other professionals, develop and implement interventions and so forth in the United States alone (Yeager et al., 2013). With such negative outcomes, aggression has been listed as an important public health problem by World Health Education since 1996 (World Health Organization, 1996).
Several categorization schemes have been proposed to organize the many types of aggression. The most common method separates aggression into instrumental aggression (including physical and verbal aggression), anger, and hostility. Buss and Perry (1992) developed a 29-item questionnaire to measure these four subtypes of aggression: (1) physical and verbal aggression, which involve hurting or harming others, represent the instrumental or motor component of behavior; (2) anger, which involves physiological arousal and preparation for aggression, represents the emotional or affective component of behavior; (3) hostility, involving feelings of ill will and injustice, represents the cognitive component of behavior; and (4) indirect aggression, which was defined as “harm delivered circuitously rather than face-to-face,” was added by Buss and Warren (2000) into the measure of aggression. Due to children's report and expressive ability and variation in definitions of aggression, various aggression measures have been established, some of which utilize a self-report method while some rely on others' reports such as parents, teachers or peers (Henry et al., 2006). In addition to informants, differences across gender and age groups have been observed in measures of aggression and its subscales. It is commonly recognized that boys are more aggressive that girls, and boys often engage in physical aggression while girls are more likely to exhibit indirect aggression (Liu, 2004). Moreover, findings on relationship between age groups and aggression are inconsistent. Lei et al. (2019) found Chinese high school students showed less aggression than elementary school students, while Tapper and Boulton (2000) claimed older children typically display greater aggression than younger children. Therefore, exploring aggression and subscales among different informants, age groups and gender is necessary.
Physical activity is generally defined as any bodily movement produced by skeletal muscles and which requires energy expenditure (Caspersen et al., 1985). Physical activity has drawn increasing attention in prevention and intervention studies, since it is cost-effective and has various positive effects for physical and mental health. Moreover, increasing evidence support that physical activity also has positive impact on physical, psychological and cognitive function (Janssen et al., 2014; Portugal et al., 2013), community participation, bonding with society and sense of identity (Haudenhuyse et al., 2014). Children and adolescents who have more opportunities to participate in physical activities have been found to show low levels of aggression (Fite & Vitulano, 2011; Molnar et al., 2008). The World Health Organization (2019) also recommends physical activity as one of the most important elements to improve mental health for youth. However, findings on the effects of physical activity intervention on aggression in children and adolescents vary due to the increasing number of studies exploring this area. Some studies found that physical activity intervention was an effective strategy to reduce aggressive behavior (Norris et al., 1992; Pan et al., 2016; Park et al., 2017; Tkacz et al., 2008; Ui & Singh, 2014), while others found no significant differences between physical activity group and the control group on aggressive behavior (Reynes & Lorant, 2002; Verret et al., 2010; Wade et al., 2018). Furthermore, some studies even demonstrated that physical activity intervention could increase aggression (Hoffman, 1988; Reynes & Lorant, 2002). These inconclusive results are also seen in aggression subtypes, including physical aggression, verbal aggression, anger, hostility, and indirect aggression (Reynes & Lorant, 2002; Tkacz et al., 2008; Trajkovic et al., 2020; Ui & Singh, 2014). Therefore, it is important to elucidate the effects of physical activity intervention on aggression and its subtypes in children and adolescents by systematically analyzing results from available literature using a meta-analysis method.
Several systematic reviews have explored the effectiveness of physical activities on externalizing problems among children and adolescents, which focused on externalizing problems (including aggression, delinquency and other conduct problems) (Gubbels et al., 2016; Spruit et al., 2016) or emphasized on a specific exercise form (Gubbels et al., 2016; Harwood et al., 2017). However, they did not provide evidence about the effects of various physical activity interventions on children's and adolescents' aggression and its subtypes. Since each subtype of aggression has different mechanism and manifestations (Liu, 2004), and physical activity not only includes exercise, sports, but also includes many specific forms such as martial arts, yoga, Judoka and so on (Caspersen et al., 1985), this review was conducted on a wide range of physical activity forms, focusing on subtypes of aggression, and considering the differing effects on different age groups and genders.
The objectives of this systematic review and meta-analysis are to: (1) determine the effect of physical activity interventions on children's aggressive behaviors; (2) explore the differences among different informants, age groups, gender, physical activity intervention characteristics.
Section snippets
Method
This study was prepared and conducted according to the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines (Moher et al., 2009).
Selection of studies
A total of 2469 studies were produced in the database searches. After removing duplicates (n = 723) and the exclusion of studies at the title and abstracts screening phase (n = 1746), 57 full texts were reviewed. Adding 2 articles from screening references, of the 59 articles identified for full text review, 15 controlled studies were included.
Characteristics of included trials
Table 1 summarized the characteristics of fifteen included studies (including 2 RCT and 13 Quasi-experimental studies). For secondary analyses, 6 trials
Discussion
This systematic review and meta-analysis found that physical activity reduced aggression among children and adolescents, especially among participants with aggressive tendency. To our knowledge, this is the first meta-analysis to include studies assessing various physical activity intervention types, explored both total aggression, as well as subscales, and discussed the differences between various population subgroups via subgroup meta-analysis method. This allowed for a more comprehensive
Declaration of competing interest
There are no any declarations of interest.
Acknowledgements
We thank Ying Dai (School of Nursing, University of Pennsylvania) for providing the guidance of literature searching, screening, and meta-analysis.
Funding
This research was in part supported by R01-HD087485 for Dr. Jianghong Liu's effort.
References (54)
- et al.
Martial arts participation and externalizing behavior in juveniles: A meta-analytic review
Aggression and Violent Behavior
(2016) - et al.
Reducing aggression with martial arts: A meta-analysis of child and youth studies
Aggression and Violent Behavior
(2017) - et al.
Changes in aggression among mainland chinese elementary, junior high, and senior high school students across years: A cross-temporal meta-analysis
Aggression and Violent Behavior
(2019) - et al.
The effects of physical activity and exercise training on psychological stress and well-being in an adolescent population
Journal of Psychosomatic Research
(1992) - et al.
A racket-sport intervention improves behavioral and cognitive performance in children with attention-deficit/hyperactivity disorder
Research in Developmental Disabilities
(2016) - et al.
Reducing child aggression through sports intervention: The role of self-control skills and emotions
Children and Youth Services Review
(2016) - et al.
The effects of physical activity interventions on psychosocial outcomes in adolescents: A meta-analytic review
Clinical Psychology Review
(2016) - et al.
Mediators of aggression in a school-based physical activity intervention for low-income adolescent boys
Mental Health and Physical Activity
(2018) - et al.
Introduction to Meta-analysis
(2021) - et al.
Behavioral effects of a locomotor-based physical activity intervention in preschoolers
Journal of Physical Activity & Health
(2018)