Effects of interventions for social anxiety and shyness in school-aged children: A systematic review and meta-analysis

Reinie Cordier, Conceptualization , Data curation , Formal analysis , Methodology , Project administration , Validation , Writing – review & editing , 1, 2, * Renée Speyer, Conceptualization , Data curation , Methodology , Validation , Writing – review & editing , 2, 3, 4 Natasha Mahoney, Data curation , Formal analysis , Writing – review & editing , 2 Anne Arnesen, Data curation , Writing – review & editing , 5 Liv Heidi Mjelve, Conceptualization , Data curation , Writing – review & editing , 3 and Geir Nyborg, Conceptualization , Data curation , Writing – review & editing 3

Reinie Cordier

1 Department of Social Work, Education and Community Wellbeing, Northumbria University, Newcastle upon Tyne, United Kingdom

2 Faculty of Health Sciences, School of Occupational Therapy, Social Work and Speech Pathology, Curtin University, Perth, Australia

Renée Speyer

2 Faculty of Health Sciences, School of Occupational Therapy, Social Work and Speech Pathology, Curtin University, Perth, Australia

3 Department of Special Needs Education, University of Oslo, Oslo, Norway

4 Department of Otorhinolaryngology and Head and Neck Surgery, Leiden University Medical Centre, Leiden, Netherlands

Natasha Mahoney

2 Faculty of Health Sciences, School of Occupational Therapy, Social Work and Speech Pathology, Curtin University, Perth, Australia

Anne Arnesen

5 The Norwegian Center for Child Behavioral Development (NUBU), Oslo, Norway

Liv Heidi Mjelve

3 Department of Special Needs Education, University of Oslo, Oslo, Norway

Geir Nyborg

3 Department of Special Needs Education, University of Oslo, Oslo, Norway

1 Department of Social Work, Education and Community Wellbeing, Northumbria University, Newcastle upon Tyne, United Kingdom

2 Faculty of Health Sciences, School of Occupational Therapy, Social Work and Speech Pathology, Curtin University, Perth, Australia

4 Department of Otorhinolaryngology and Head and Neck Surgery, Leiden University Medical Centre, Leiden, Netherlands

This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Associated Data

All relevant information is within the manuscript.

Abstract

In school, shyness is associated with psychosocial difficulties and has negative impacts on children’s academic performance and wellbeing. Even though there are different strategies and interventions to help children deal with shyness, there is currently no comprehensive systematic review of available interventions. This systematic review and meta-analysis aim to identify interventions for shy children and to evaluate the effectiveness in reducing psychosocial difficulties and other impacts. The methodology and reporting were guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement and checklist. A total of 4,864 studies were identified and 25 of these met the inclusion criteria. These studies employed interventions that were directed at school-aged children between six and twelve years of age and described both pre- and post-intervention measurement in target populations of at least five children. Most studies included an intervention undertaken in a school setting. The meta-analysis revealed interventions showing a large effect in reducing negative consequences of shyness, which is consistent with extant literature regarding shyness in school, suggesting school-age as an ideal developmental stage to target shyness. None of the interventions were delivered in a classroom setting, limiting the ability to make comparisons between in-class interventions and those delivered outside the classroom, but highlighting the effectiveness of interventions outside the classroom. The interventions were often conducted in group sessions, based at the school, and involved activities such as play, modelling and reinforcement and clinical methods such as social skills training, psychoeducation, and exposure. Traditionally, such methods have been confined to a clinic setting. The results of the current study show that, when such methods are used in a school-based setting and involve peers, the results can be effective in reducing negative effects of shyness. This is consistent with recommendations that interventions be age-appropriate, consider social development and utilise wide, school-based programs that address all students.

Introduction

Shyness is commonly experienced by school-aged children [1]. Despite being a frequently used term, there is a diversity of constructs that underpin ‘shyness’, including behavioural inhibition, social reticence, social withdrawal, anxious solitude and social anxiety [2]. There have been several approaches to defining shyness in the past. Some conceptualisations theorise shyness as either behavioural inhibition to the unfamiliar (i.e., wariness in unfamiliar situations) or social withdrawal [i.e., elevated rates of solitary behaviour or symptoms of social anxiety disorder; 3–7]. In contrast, substantial literature has investigated shyness as encompassing individual differences in wariness or anxiety in novel situations, embarrassment or self-conscious in anticipation of social evaluation and reticence in social situations [7]. Shyness has also been considered from a developmental perspective, proposing an interactional child-by-environment model. By this model, behavioural inhibition and social withdrawal are considered risk factors for further social anxiety. Interactions between the child and the environment, and the child and their parents and peers, can either promote or diminish the risk of later anxiety [4,8,9].

Taxonomy of shyness

In order to organise and operationalise the various concepts of shyness in use, Rubin, Coplan [7] proposed a taxonomy of shyness. This taxonomy places behavioural solitude (i.e., lack of interaction in presence of peers) as the over-arching, observable behaviour of shyness. The source of this solitude is either internal, termed social withdrawal (i.e., removing oneself from social interaction) or external, termed active isolation (i.e., being excluded by others). If the source is internal (i.e., social withdrawal), the motivation for withdrawal is either by preference, termed social disinterest, or a result of fear or wariness. The source of fear is then split into four categories: 1) behaviour inhibition (i.e., fear of novelty); 2) anxious solitude (i.e., wariness in familiar social situations); 3) shyness (i.e., wariness of social novelty and/or perceive evaluation); and 4) social reticence (i.e., observed display of onlooker behaviours). In this taxonomy, these fears and behaviours can become clinically significant over time and manifest as a social anxiety disorder. This taxonomy provides a clear conceptualisation of shyness and social anxiety, and outlines observable behaviours, sources, motivations and specific fears.

Shy children in school

In addition to the potential manifestation of social anxiety disorder theorised by Rubin, Coplan [7], children with shyness may also experience a range of other difficulties that, although not clinically diagnosable, can vastly impact their wellbeing, social networks and academic performance [10]. Many of these difficulties are experienced at school, where peer interactions are an integral component of the environment. Shy children are often quiet across a range of situations in school, both in the classroom and in social situations [11]. Talking, in or outside of class, can make a child the centre of attention and open to social evaluation, which sits at the centre of the taxonomy of shyness. Shy children have fewer in-class interactions and respond less often to direct or class-wide questions than their non-shy peers [12]. Research has shown that shy children often have lower academic attainment, poorer performance on tests of language development, and are more likely to have difficulty adjusting at school [10].

Shyness is also associated with psychosocial challenges in school. Shy children often have a limited number of friends and are at risk of peer victimisation and exclusion [7,13]. They may also use social withdrawal as a way to avoid or cope with peer victimisation [14]. Shyness is positively associated with somatic complaints, school-related stress, anxiety and depressive symptoms [15,16]. Shyness can increase over time, predicting difficulties later in adolescence [17]. Shy children often have poor social skills and high levels of anxiety and depression symptoms in early adolescence [17]. Longitudinal studies show that shyness and social withdrawal are significant risk factors for social anxiety disorder [8,18]. These results are aligned with the Rubin, Coplan [7] taxonomy of shyness and social anxiety, demonstrating the theorised pathway to social anxiety disorder.

School-based interventions for shy children

Given the short- and long-term psychosocial and academic outcomes for shy children, there have been multiple attempts at buffering the impacts of shyness. In the classroom, teachers can use concepts, such as shyness, as a tool to tailor how they work with an individual child [19]. Teachers at a Norwegian elementary school broadly categorised shy children in their classroom as either, 1) withdrawn, 2) anxious, and/or 3) having poor self-esteem. These categories then informed the support given to the individual child, including cognitive support and feedback and encouraging active learning [19]. Informal, teacher-facilitated support or intervention is a common response to shyness within the classroom, as teachers recognise shy children and the potential problems they encounter [20–22]. Teachers report employing social learning strategies, such as verbal encouragement, praise and modelling behaviour, as well as peer-focused strategies to promote inclusion, such as encouraging joint activities [20]. However, the effectiveness of these individual attempts is limited to within the classroom and may not impact poor psychosocial outcomes for shy children in broader contexts.

Beyond classroom support, there are many different structured interventions targeting shyness in school-aged children. Clinical interventions are typically conducted in non-naturalistic settings with homework-style practice in naturalistic settings, and comprise of social skills training, psychoeducation, cognitive restructuring and exposure tasks [8]. Criticisms of this approach are that such interventions do not consider nor change the environment itself and focus on treating social anxiety disorders, ignoring shyness more broadly [8]. Clinical interventions need to be age-appropriate and consider cognitive and social development, social context and parent involvement [23]. As shy children are often excluded or victimised by their peers, interventions need to consider the environment and peer interaction. Developmental interventions include peers in the intervention itself, aiming to increase the use of successful social skills in naturalistic settings [8]. However, this approach requires school resources and willingness of peers to be involved. Crozier [1] suggests that a focus on individual screening and pathologising shyness may not lead to effective intervention, as not all shy children develop anxiety disorders. Wider, school-based programs that address all student’s social confidence, instead of targeted interventions, may be more suitable intervention for shyness [1]. Given the wide range of intervention approaches and intervention programs themselves, there is no clear best-practice for interventions for shy children. This is further complicated by inconsistent use of terminology related to shyness [1].

To reduce academic and concomitant psychosocial difficulties in school for shy children, there is a need for effective, feasible interventions. To date, there is no comprehensive systematic review of the available interventions for shy children. This systematic review and meta-analysis aim to provide an overview of the available interventions for shy children aged six to twelve years, describe the characteristics of the interventions, summarise intervention strategies being used, and determine their overall effectiveness, as well as effectiveness of interventions in relation to the following domains: 1) setting where the interventions is delivered; 2) mode of delivery; 3) intervention focus; and 4) rater of outcome measures.

Method

The methodology and reporting on this systematic review were guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement and checklist. The PRISMA statement and checklist supports researchers in the critical and transparent reporting of systematic reviews in areas of health care [24,25].

[The PRISMA checklist is provided as Supporting Information].

Eligibility criteria

To be eligible for inclusion in this systematic review, studies were required to describe an intervention in school-aged children (between six and twelve years old) for social anxiety and shyness. Only studies describing both pre- and post-intervention measurement in target populations of at least five children were included. Only original articles published in English were considered for eligibility. Conference abstracts, case reports, reviews, student dissertations and editorials were excluded.

Data sources and search strategies

Literature searches were conducted in five electronic databases: CINAHL, Embase, Eric, PsycINFO and PubMed. All publication dates up to 23 rd December 2020 were included. The search strategies per database are listed in Table 1 .

Table 1

Methodological quality and level of evidence

The Qualsyst critical appraisal tool by Kmet [26] and the National Health and Medical Research Council (NHMRC) Evidence Hierarchy Levels of Evidence [27] were used to assess the methodological quality of the included studies: I (systematic review of level II studies); II (randomised controlled trial); III-1 (pseudo-randomised controlled trial); III-2 (comparative study with concurrent controls); III-3 (comparative study without concurrent controls); IV (case series with either post-test or pre-post outcomes). The Qualsyst tool provides a systematic, reproducible and quantitative means of appraising the methodological quality of research across a broad range of study designs. The Qualsyst consists of 14 items. All items have a three-point ordinal scoring (yes = 2, partial = 1, no = 0). A total score can be converted into a percentage score. A score above 80% is considered strong quality, a score of 60 to 79% considered good, a score of 50 to 59% considered adequate, and a score below 50% considered poor quality. Studies with poor study quality were excluded from further analysis in this review.

Data extraction

A data extraction form was created to extract data from the included studies under the following categories: study design (according to NHMRC level), methodological quality (Qualsyst), participants (numbers, groups), age (range, mean, standard deviation), gender, intervention, inclusion criteria of the individual study (if stated), outcome measures and treatment outcomes. To ensure the meta-analysis focused on factors that impact on shyness, authors identified and extracted only data collected using the main outcome measure related to shyness (see Table 2 ). Due to the lack of dedicated shyness outcome measures in literature, the most suitable outcome measure related to shyness was chosen. Data including means, standard deviations, and sample sizes were extracted from the included studies to enable the calculation of the overall effect of shyness interventions (within-group pre-post intervention comparisons), and comparisons between shy children and control groups (between-group experimental vs. control intervention group comparisons).

Table 2

1 NHRMC hierarchy: Level 1 Systematic reviews; Level II Randomized control trials; Level III–1 Pseudo-randomized control trials; Level III–2 Comparative studies with concurrent controls and allocation not randomized (cohort studies), case control studies, or interrupted time series with a control group; Level III–3 Comparative studies with historical control, 2 or more single-arm studies, or interrupted time series without a control group; Level IV Case series.

2 Methodological quality: Strong > 80%; good 60–79%; adequate 50–59%; poor < 50%.

ADHD = Attention Deficit/Hyperactivity Disorder; BFNE-R = Brief Fear of Negative Evaluation- Revised; BIQ = Behavioural Inhibition Questionnaire; CBCL = Child Behaviour Checklist; CBS = Child Behaviour Scale; CGI = Clinical Global Impressions; CIRP = Children’s Intervention Rating Profile; DSM-IV = Diagnostic and Statistical Manual of Mental Disorders; GAD = Generalised Anxiety Disorder; K-GAS = Children’s Global Assessment Scale; MASC = Multidimensional Anxiety Scale for Children; MPI = Maudsley Personality Inventory; NOS = Not Otherwise Specified; OCD = Obsessive Compulsive Disorder; ODD = Oppositional Defiance Disorder; PAS = Preschool Anxiety Scale; RCADS-MDD = Revised Child Anxiety and Depression Scale–Major Depressive Disorder; SAS = School Anxiety Scale; SAS-A = Social Anxiety Scale for Adolescents; SCARED = Screen for Child Anxiety Related Emotional Disorders; SDQ = Strengths and Difficulties Questionnaire; SIBS = Student Internalising Behaviour Screening; SOC = Sense of coherence; SPAI = Social Phobia and Anxiety Inventory; SPAI-C = Social Phobia and Anxiety Inventory for Children; STAI-C = State-Trait Anxiety Inventory for Children; STSC = Short Temperament Scale for Children; SUD = Subjective units of distress; TRF = Teacher Report Form; + main shyness outcome measure extracted for meta-analysis.

Data items, risk of bias and synthesis of results

Risk of bias in the included studies was assessed at an individual study level using the Kmet appraisal checklist [26]. Risk of bias was minimised in this process by having a full overlap between independent abstract and article reviewers, and by two independent assessors independently scoring 100% of the methodological quality of included studies. Final study selection and quality assessment were the result of consensus-based ratings. Discrepancies were resolved by involving a third reviewer. No author of this review was affiliated with any of the included studies. Extracted data were synthesised in relation to the methodological characteristics of each included study and the findings of individual studies with regards to the treatment outcomes of shyness interventions.

Meta-analysis

Using the extracted data from the main outcome measure related to shyness, estimates were calculated of pooled effect sizes weighted by sample size using random-effects models for summary statistics. To determine potentially confounding variables, effect sizes of shyness interventions were grouped by setting (school, clinic and/or home), focus (child and/or parents), mode of delivery (individual and/or group sessions), and rater of outcome measures (child, parents, clinician and/or teacher). The Hedges-g formula for standardized mean difference (SMD) with a 95% confidence interval (95% CI) was used to report effect sizes. A test for overall effect for each intervention setting, mode, focus and outcome rater produced a weighted effect size (z). Tests for heterogeneity were conducted to identify inconsistency in treatment effects, included I 2 and chi-square (Q). All statistical analyses were performed using software package Comprehensive Meta-Analysis Version 3.3.070 (Biostat; Englewood, NJ, USA).

Within-groups effects were examined by analysing the pre-post data for studies both with and without control groups. The benefit of within-groups analyses is that it allows the examination of the effect of an intervention in and of itself, without controls. Between-groups analyses (comparing results of control group to that of intervention group) were also conducted. This allows comparison of different forms of interventions against each other.

Results

Systematic review

Study selection

A total of 4,864 articles were identified (CINAHL: n = 605, Embase: n = 1158, ERIC: n = 1849, PsycINFO: n = 968 and PubMed: n = 929). After the removal of duplicate articles, 5299 abstracts were screened. A total of 149 studies were assessed at a full text level for eligibility. Of these, 129 were excluded and 20 were included (see Fig 1 ). No studies were excluded due to poor quality. An additional five studies were included through searching the reference lists of the 20 studies that met the inclusion criteria. This resulted in a total of 25 included studies.

Flow diagram of the review process according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA).

Adapted from Moher et al.

Participants of studies included in the systematic review

The total number of participants across the 25 included studies was 1,895, with the average participants across studies 75.8. Griffin, Caldarella [28] had the largest sample of 388 participants and Cook, Xie [29] the smallest sample of 5 participants. The average age of total participants across the studies was 9.1 years (SD = 5.4), with the average age of the total sample not reported in nine studies. Of the 25 studies, only five had more male than female participants, with four studies not reporting the gender of the total or sub-samples. While a range of diagnoses were reported across some studies, 13 studies reported the sample to be typically-developing and five studies did not report diagnosis. Studies were conducted across nine countries, with the highest number conducted in the USA (n = 10), followed by Australia (n = 4). Additional details on participant characteristics are reported in Table 2 .

Study design, methodological quality and risk of bias of studies included in the systematic review

Most studies were randomised or pseudo-randomised control trials, with only three employing a multiple baseline design (see Table 2 ). The methodological quality for each study according to Kmet criteria is reported in Table 2 . The average methodological quality rating across all studies was 83.4% (SD: ±8.7, range: 64–96%), indicating “strong” methodological quality. Of the studies, 17 were rated as “strong”, with all others rated to have “good” methodological quality. No study was rated to have adequate or poor methodological quality.

Shyness outcome measures

While studies reported several outcome measures, only those relevant to shyness and/or social anxiety were the focus of this review. Across categories of self-report, parent-report, teacher-report, clinician-rating and observation measures of shyness, self- reported (n = 13) and parent-reported (n = 13) shyness outcome measures were most frequently used and clinician-rating was used least across studies (n = 7; see Table 2 ). Using the categories of outcome measures above, nine studies used two different types of outcome measures, seven studies used only one type of outcome measure, and nine studies used three or more types out outcome measures.

Interventions

The majority of studies included an intervention that was delivered weekly (n = 15), in a child group format (n = 14), in the school setting (n = 10). Only four studies reported session durations of 40 minutes, with 14 reporting sessions for 60 minutes or longer. Intervention delivery was reported to be at least 7 weeks in 17 studies (see Table 3 ).

Table 3

Descriptions of active intervention components reported in the included studies were reviewed and categorised. In terms of active intervention components, the studies used psychoeducation (n = 11), in-vivo exposure (n = 11), SST (n = 9), therapist modelling (n = 9), cognitive restructuring (n = 8), behaviour modification (n = 6), peer-mediation (n = 6) and video-modelling (n = 1). Across the studies, 12 used only one or two intervention components, while only five studies used a combination of 4 or more intervention components (see Table 3 ).

Reported treatment outcomes

Across the included studies, significant reduction was reported for anxiety (n = 13), social phobia (n = 3), and internalising behaviours (i.e., withdrawal, avoidance, and isolation; n = 8). A significant improvement was found for play skills (n = 2) and aspects of social functioning (n = 8); social competence, social skills, social interaction, social adjustment, interpersonal skills, peer victimisation, perceived social support from peers, and pro-social behaviour. Further, four studies reported treatment gains to be maintained at follow-up periods between 6 months and 5 years (see Table 3 ).

Meta-analysis

Effects of interventions

Twenty of the 25 studies were included in the meta-analysis. Five could not be included in the analysis as the data required were not reported [28,31,32,34,36]. Authors were contacted to collect the required data, but no responses were received.

Overall treatment effects were calculated for shyness interventions on within-group pre-post outcome measures. Sub-group analysis was conducted to compare the effect as a function of intervention characteristics: 1) setting (i.e., clinic, home, school, online or a combination); 2) mode of delivery (i.e., group interventions, individual interventions or both); 3) intervention focus (i.e., parent focused, child focused or both); and 4) rater of outcome measure (i.e., clinician-rated, parent-rated, self-report, teacher-rated or a combination).

Between groups analysis was also conducted to compare experimental groups post-interventions scores with those of the control groups. A further 3 studies were excluded from this analysis as they did not include control groups. The following four control condition types were included: 1) waitlist control groups where participants served as an untreated comparison group who eventually went on to receive the intervention; 2) control groups that received no intervention; 3) alternative treatment controls where participants received an intervention that did not have the approach of the intervention being tested; and 4) medication control groups, where participants received medication instead of the behavioural intervention.

Overall effect of shyness interventions

Effect sizes ranged from 0.04 to 3.18 in the within-group pre-post intervention without groups analysis, as shown in Fig 2 . Of the 20 studies included 75% (n = 15) produced a large effect size and 15% (n = 3) produced a moderate effect. An effect size of < 0.2 was measured in 10% (n = 2) of the studies. The overall intervention effect was large and statistically significant (z(20) = 7.03, p < .001, Hedge’s g = 1.21, 95% CI = 0.87–1.54). The between-study heterogeneity was significant Q(19) = 137.16, p < 0.001) and 86.2% of true variability (I 2 ) could be explained by individual study characteristics.