Introduction

Adolescents are frequently at the center of social interventions designed to develop or enhance personal, social, and life skills. Such skills encompass a broad spectrum of capabilities, with varied definitions and interpretations. As defined by the World Health Organization (WHO), life skills are “abilities for adaptive and positive behavior that enable individuals to deal effectively with the demands and challenges of everyday life” (World Health Organization. Division of Mental Health 1994). A broader definition might encompass the “skills that enable individuals to succeed in the diverse environments they inhabit, such as school, home, and their neighborhoods. Life skills can be behavioral (such as communicating effectively with peers and adults), cognitive (making effective decisions), interpersonal (being assertive), or intrapersonal (setting goals)” (Danish et al. 2004). The aim of skills-based interventions is to arm individuals with the knowledge required to acquire, apply, and mobilize their skills across various domains.

Adolescence is a particularly sensitive phase of life where different behaviors, sometimes problematic, can emerge. There has been an increasing demand for interventions aimed at enhancing adolescent skills. These interventions are designed to help adolescents to cope with life challenges and transition to adulthood, focusing on areas such as addictive behaviors, violence, and broader themes such as school environment. While numerous interventions targeting life skills have been developed, less is known about their underlying components, particularly the obstacles and levers for action ensuring their effectiveness. Identifying the key components of the interventions that can significantly contribute to their success or failure is indeed crucial. This scoping review is aimed at identifying the interventional components that can effectively enhance adolescents’ life skills across various areas.

Methods

This review adheres to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for scoping reviews (PRISMA-ScR) guidelines (Tricco et al. 2018) (see supplementary file).

Research strategy

This review included peer-reviewed literature published over a 6-year period (2016–2022). We reviewed articles across various disciplines, including public health, humanities, and social sciences, to integrate a large panel of interventions among adolescents.

Articles were selected based on the following inclusion criteria:

  • Articles reporting evaluation results of interventions or programs designed to improve life skills, social skills, personal skills, or psychosocial skills

  • Population: children/adolescents/young adults aged 10 to 21 years

  • Location: EU, US, or Canada

  • Language: English, French, or Spanish

  • Publication date: between 01/01/2016 and 31/08/2022

Articles characterized by the following were excluded:

  • Presented interventions targeting a population with specific needs (youth with mental, emotional, behavioral, or physical disorders)

  • Featured interventions implemented to treat a diagnosed disorder (such as autism, facial paralysis, HIV, and so forth)

  • Discussed interventions implemented in specific settings (such as the court system, foster care, and so forth)

  • Were situated outside the predefined geographical zones or were written in languages other than English, French, or Spanish

Databases searched

We selected six relevant databases for this purpose: PubMed, PsycINFO, APA PsycArticles, Psychology & Behavioral Sciences Collection, SocINDEX, and Web of Science. The search was conducted in September 2022, considering all available articles. Keywords used included “prevention OR intervention OR program” AND (“life skills” OR “social skills” OR “personal skills”) AND (“adolescents” OR “teenagers” OR “young adults”). Detailed search parameters for each database can be found in Table 1 of the supplementary file 2.

Screening

All identified studies were reviewed through a rigorous double-blind screening process conducted by two professionals using the Covidence tool (https://www.covidence.org/). In the first step, they evaluated the relevance of each article based on its title and abstract. At this stage, irrelevant articles were excluded. Any discrepancies were resolved via discussion. The full text for each retained article was then examined according to the inclusion/exclusion criteria. In the event of disagreement over the inclusion or exclusion of an article, consensus was reached through further review and discussion.

Data extraction

In this review, we sought to identify factors that facilitate or inhibit the effectiveness of interventions or programs. We focused on the practical implementation of interventions and on factors, contexts, or processes identified as having an impact on their effectiveness. These elements, called “key functions” (Hawe et al. 2004) or “levers,” refer to an aspect of an intervention that contributes to its effectiveness. Such elements are components that can be transferred to a new context when implementing an intervention (Cambon et al. 2012).

Three professionals independently extracted each study, followed by a consensus discussion before drafting this review. The objective of this review was not to compare intervention efficacy but to identify various factors contributing to the intervention’s effect. Thus, we deliberately avoided categorizing the quality of the studies, to maintain an overview of current interventions.

Results

A total of 3579 articles were retrieved, of which 70 met the inclusion criteria. The flowchart in Fig. 1 details each stage of this process. In the first step, we evaluated the relevance of each article based on its title and abstract, resulting in 1503 articles. Of these, 1336 were deemed irrelevant to the scope of our review. From the remaining 167 articles, 97 were discarded due to study location, absence of intervention or evaluation, sample population, or article type. Consequently, 70 articles fulfilling the inclusion criteria were selected for data extraction.

Fig. 1
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Flow diagram

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Characteristics of the interventions

Most of the selected articles centered on a specific intervention, each with a distinct implementation, theoretical framework, objective, and so on. Large-scale programs such as IPSY (Information + Psychosocial Competence = Protection), Ready for Life, and LifeSkills Training (LST) have been frequently published and evaluated and recurred several times in our sample (Weichold and Blumenthal 2016; Giannotta and Weichold 2016; Spoth et al. 2016; Velasco et al. 2017; Haug et al. 2017, 2021; Vroom et al. 2020).

The studies were primarily published in 2016, 2020, and 2021. The interventions took place in Europe (n = 40, 57.1%) and in North America (n = 30, 42.9%). Within Europe, the UK and Italy had the highest number of publications (eight and six, respectively).

Targeted population

The mean age of individuals targeted by the interventions was 13.6 years, with a range from 7 to 20 years. More than half of these interventions were designed for children aged 12 to 15 years.

Setting

Most of the studied programs were school-based (n = 45, 64.3%), while 18 (25.7%) were conducted in other spaces such as associations or sports facilities outside school hours. Four were online, and two were implemented in open-air settings. One program was hybrid, both school-based and online.

Objectives and topics

We identified the objective of each intervention (i.e., the skills or competencies intended to be activated by the program) and the topic or field in which these competencies were intended to be applied.

Objectives

Almost all studies defined the intervention’s objective. While many articles described interventions broadly targeting life skills (n = 24, 34.3%), some focused on social skills (n = 17, 24.3%) and others focused on social and emotional skills (n = 8, 11.4%) or various combined skills such as life skills and literacy (Velasco et al. 2017) or empowerment and social skills (Whitson et al. 2020). Literacy was targeted by three programs (Huic et al. 2017; Velasco et al. 2017; Meng et al. 2018), and empowerment was the goal of another three programs (DeBate and Bleck 2016; Lewis et al. 2018; Whitson et al. 2020). Leadership (Richmond et al. 2018; Bates et al. 2020) and violence prevention (Garaigordobil and Martínez-Valderrey 2016; Barnes et al. 2017) were each the focus of two programs.

Topics

Only 50 studies (71.4%) specified the application area of the competencies potentially targeted by these programs. Among these programs, 16 (22.9%) aimed at enhancing health and mental health, and 10 (14.3%) targeted consumption of legal and illicit psychoactive products. Violence and/or harassment were frequently targeted (n = 11, 15.7%). Other fields included professional and adulthood responsibilities (n = 6), school environment (n = 3), and sexual risks (n = 2). Of the 70 interventions, 14 (20%) incorporated physical activities, three involved music practices, and two utilized yoga activities.

Implementation of interventions

Most programs were long-term (i.e., lasting more than 2 months), with 33 (47.1%) lasting more than 10 weeks, including 10 (14.3%) that lasted more than 30 weeks. Eight programs (11.4%) were more sporadic, consisting of one or two sessions. Among these, seven (10%) were intensive interventions, requiring several hours per week. The intensity of the programs varied: 22 (31.4%) were intensive and 27 (38.6%) were steady (occurring once a week, for instance).

In 20 (28.6%) articles, the intensity or frequency of the studied intervention was not mentioned. Regarding the individuals involved in the programs, 29 (41.4%) engaged school staff and 39 (55.7%) had non-school-affiliated professionals. For 46 (65.7%) interventions, the facilitators or individuals in charge of the intervention received specific training for this purpose.

Program evaluations

Most evaluations were quantitative (n = 60, 85.7%), with only a few being qualitative (n = 4, 5.7%) or having a mixed methodology (n = 6, 8.6%). Regarding results, 54 (77.1%) studies reported positive outcomes, 13 (18.6%) showed mixed results, and none produced negative results. Among the evaluations, 12 (17.1%) presented variable results according to sex (n = 7, 10%) or other determinants, such as ethnic group or background.

Obstacles and levers

As mentioned earlier, this review aimed to focus on key functions (Hawe et al. 2004), levers, and obstacles (i.e., aspects of an intervention that contribute to or limit its effectiveness). Therefore, we identified and documented any elements that may have influenced the outcomes of an intervention. This was done by either identifying them ourselves through evaluation, or noting those already highlighted by the authors of the article. Various levers with positive effects were identified, as were elements that served as moderators or obstacles.

Levers

Of the 70 papers, 44 (62.9%) mentioned levers and 16 identified potential elements that could contribute to the effect of an intervention. These levers fell into three categories: those related to the individuals involved in the intervention, those related to the implementation and modalities of the intervention, and those related to interpersonal elements within the intervention (e.g., levers activated during an intervention that are associated with the relationship between student and intervention staff). Some studies showed that their interventions were based on several levers (n = 15).

People involved and their participation

Overall, 16 articles (22.9%) cited the involvement and/or participation of specific individuals as significantly contributing to the intervention’s outcome. Twelve interventions leveraged a community or local group (including whole school communities, parents, and neighborhoods) to foster change, which reflects an ecosystemic approach (Barkoukis et al. 2016; Bean and Forneris 2016; Garaigordobil and Martínez-Valderrey 2016; Velasco et al. 2017; Bonell et al. 2018b; Lewis et al. 2018; Meng et al. 2018; Gouveia et al. 2019; Iyer and Iyer 2019; Bates et al. 2020; Johnson et al. 2021; LeCroy et al. 2021). Other programs involved professionals or institutional representatives who could add value to the program, such as a pediatric care provider (Clifton et al. 2022).

The link between a research institute or a university and the program (Sullivan et al. 2017; Haug et al. 2021) could also influence the outcome of the intervention by enhancing the program’s credibility or ensuring the intervention’s independence. One study noted that program staff not being associated with the school fostered a sense of anonymity (Haug et al. 2017) that could benefit the intervention. The empowerment and involvement of facilitators or trained staff was also widely cited as a lever, identifiable through the intervention being delivered according to the facilitator’s wishes (Carreres-Ponsoda et al. 2021) or by the personal involvement and commitment of the staff (Vroom et al. 2020).

Implementation modality

The modalities of implementation were frequently cited as a lever (n = 25). These are summarized below.

  • Pedagogical approach: Various pedagogical elements were identified to enhance intervention outcome, including active learning (Lewis et al. 2018; Rizzi et al. 2020; Pavarini et al. 2022), recreational activities (Barnes et al. 2017), perspective-taking and planning for action (Wallrich et al. 2021), realistic experience (Barker et al. 2016), focus groups (Allen and Rhind 2019), roleplaying games (Moulier et al. 2019), real-time feedback and reinforcement (Zarglayoun et al. 2021), self-coaching, co-learning and autonomy (Barker et al. 2016; Bonell et al. 2018b; Lewis et al. 2018), flexibility and openness to students’ ideas (Ahmed and Schwind 2018), using sports as an activity to facilitate knowledge acquisition (Pesce et al. 2016; Greco et al. 2019), using engaging and adapted intervention support (Lakes et al. 2019), and combining with another goal or training model (Munoz-Llerena et al. 2021; Casado-Robles et al. 2022).

  • Temporality: The duration and intensity of interventions were widely cited as active components (Barkoukis et al. 2016; Sullivan et al. 2017; Allen and Rhind 2019; Maalouf et al. 2019; Bates et al. 2020; Koszałka-Silska et al. 2021; Clifton et al. 2022). A study of an evidence-based program emphasized the need for at least 15 sessions a year (Maalouf et al. 2019), while another study on a physical educational intervention suggested that shorter programs maintained high levels of motivation (Koszałka-Silska et al. 2021). Routine (Meng et al. 2018) and regularity (Sánchez-SanSegundo et al. 2020) were also mentioned as important, as was the timing of an intervention during adolescence, with one study suggesting that early adolescence may be best (Spoth et al. 2016).

  • Methodology: The delivery method of programs was also frequently cited. The activities should be focused (Sánchez-SanSegundo et al. 2020; Rizzi et al. 2020), sequenced or progressive (Richmond et al. 2018; Sánchez-SanSegundo et al. 2020; Rizzi et al. 2020; Wallrich et al. 2021), delivered in small groups (Richmond et al. 2018), structured and meaningful (Garaigordobil and Martínez-Valderrey 2016; Clifton et al. 2022), and practical when using a virtual world (Johnson et al. 2021).

  • Setting: Some papers mentioned an intervention’s setting as influencing its effectiveness. Various elements were noted, such as a comfortable environment that allows participants to feel at ease (LeCroy et al. 2021), a realistic experience in a virtual intervention (Barker et al. 2016), a safe and secure place even when the intervention takes place in a school classroom (Lakes et al. 2019), access to new locations (Richmond et al. 2018; Bates et al. 2020), or even on-demand interventions (as in the case of a cell phone application) (Haug et al. 2017; Iyer and Iyer 2019).

  • Adaptations: While some papers suggested that an intervention should be designed for the majority of adolescents (Spoth et al. 2016; Sullivan et al. 2017), others indicated that it should be tailor-made, adapted to a specific targeted population (Paz Castro et al. 2022; Martinez et al. 2022), or adjusted according to a coach’s strengths or wishes (Carreres-Ponsoda et al. 2021).

  • Intentionality: Another important element is that a program must explicitly address the goal defined upstream, by tackling its objectives directly (Bean and Forneris 2016; Allen and Rhind 2019; Sánchez-SanSegundo et al. 2020).

Relational elements

Eight articles (11.4%) reported that interpersonal elements enhanced intervention outcomes. Certain papers hypothesized that interventions are facilitated by a relationship based on trust and credibility between participants (Ahmed and Schwind 2018; Mala et al. 2022), by student involvement (Barnes et al. 2017; Mala et al. 2022), freedom of expression (Sheltzer and Consoli 2019), caring adult leaders (Sheltzer and Consoli 2019; Bates et al. 2020), or sharing a common interest (Millar et al. 2020).

Limiting factors

Intervention elements

A few articles identified elements of the intervention itself as limiting factors. For instance, teenagers said they found few opportunities to apply the skills they had learned, or felt that these skills were not relevant to their daily lives (Allen and Rhind 2019). Another article mentioned the lack of immersion of an intervention and its use of a first-person perspective (Zarglayoun et al. 2021) as limiting factors. Another study questioned the cognitive maturity of the children targeted in the intervention (Sánchez-SanSegundo et al. 2020).

Implementation fidelity

Implementation fidelity was frequently cited to explain the failure or limited effect of an intervention. Several articles reported that variability in this factor could account for the observed effects (Bonell et al. 2018b; Yanagida et al. 2019). This variability in implementation was also observed in studies that mentioned other limiting factors such as sociodemographic characteristics and personality differences between coaches (Mala et al. 2022) or individual characteristics of the beneficiaries that could impact the effects of universal prevention programs, such as equitable access to the program (Bates et al. 2020) or gender (Bickham et al. 2021).

Organizational

Some limiting factors were considered organizational, referring to the setting of an intervention. These included a lack of comfort (Ahmed and Schwind 2018), the fact that the interventions took place indoors or the absence of a natural environment that could facilitate an emotional experience (Koszałka-Silska et al. 2021), or unfavorable weather conditions (Scheithauer et al. 2020), leading to lower motivation among both coaches and adolescents.

Group composition

Another limiting factor was related to the composition of the group receiving the intervention. Issues noted included newly formed groups, leading to a lack of bonding or comfort between participants (Koszałka-Silska et al. 2021), or the presence of a negative atmosphere within the group (Obsuth et al. 2016).

Motivation

Finally, some papers identified adolescents’ motivation (directly linked or not to the intervention) as a factor limiting the effect of an intervention. This element is linked to lower participation (Scheithauer et al. 2020) and reduced engagement (Obsuth et al. 2016).

Discussion

This literature review considered the elements that facilitate or impede the effectiveness of more than 60 interventions, largely targeting children in a school setting. These interventions span a variety of personal, social, and life skills, focusing on areas such as health, mental health, substance use, and violence. Positive elements included the individuals involved (such as whole school, parents, or community) and their roles, training, and involvement, the modality of implementation (such as the interventions’ methodology, setting, or pedagogical approach), and relational elements (between participants and with the facilitators). Limiting factors primarily pertained to implementation, such as fidelity (in cases where an intervention was transferred to another setting), organizational constraints, and group composition.

For reasons of feasibility and homogeneity, our review focused on a certain geographical area and time period. Although substantial, it is not exhaustive, and its generalizability should be considered accordingly. However, the review provides a thoughtful examination of key components of interventions targeting adolescent skills and how these interventions should be designed, pre-tested, and/or evaluated.

Overall, our findings underscore the need to design interventions in a more participatory manner to involve professionals, adolescents, and sometimes the community at each stage of the intervention (design, implementation, and during sessions). Whether concerning the pedagogical approach (such as how adolescents are involved in the learning process or the method of implementing the session), the aim of the intervention, its implementation modalities, or the relationships involved, the participation of all stakeholders should be encouraged and emphasized.

In addition, creating a secure environment is vital when designing interventions targeting life skills among adolescents. Indeed, the objectives, strategies, and even settings of interventions should be easily understandable to prevent confusion, mistrust, and consequently a lack of motivation or involvement. For example, the regularity of sessions, the intentionality behind the intervention, and the fact that it is carried out in a safe place can all contribute to creating a reliable interventional environment.

Finally, incorporating practical applications can help anchor the interventions in adolescents’ lives. Interventions are often highly theoretical and rarely directly applicable. Adolescents may benefit from a more practical and global approach that could be more easily applied to their everyday lives.

More broadly, we found that interventions aiming at improving life skills among adolescents usually take a small-scale focus, rarely addressing broader, more intersectional targets such as school policies and systems. In our sample, only one paper focused on modifying the school environment (Bonell et al. 2018a). Likewise, there is a significant lack of detail on preliminary implementation work, including continuity with grades prior to lower secondary school, inter-school collaboration, external institutional partnerships that finance the construction of schools, or the social and sociocultural structures of a district. Furthermore, there is no clarification on how to sustain intervention approaches, although this is a crucial factor for embedding life skills in young people. Finally, adverse living conditions (such as poverty, lack of access to healthcare, inadequate housing, and so forth), which directly impact physical, mental, and social health (Wilkinson et al. 2004), are seldom addressed by such interventions. Moreover, while life skills are useful, they may not overcome the daily hurdles present in adverse living conditions.

The results of this review were shared with a group of French field professionals involved in interventions targeting adolescents. They found the results to be consistent with their own practices but supplemented the findings with two important elements: (i) consistency in approaches between different local establishments (such as after-school care, leisure centers, and so forth) and (ii) considering the role of psychosocial skills in the curriculum and in the daily lives of young people in school. All of this underscores the importance of continuing studies that incorporate environmental and structural elements, in addition to strictly individual approaches with pupils.

Conclusion

This work identified key elements that may influence the outcome of interventions aimed at helping adolescents manage the transition to adulthood. Three main categories emerged: participation and involvement of participants, creation of a secure environment for the intervention, and the anchoring of change in adolescents’ lives. In addition, the small scale of the interventions in terms of people and institutions implicated and in terms of continuity or sustainability points out the weakness in terms of the viability of these interventions (Chen 2010). Our findings highlight the need for authors to present and robustly detail the interventions carried out in the literature, including information on the purpose of the intervention and the key underlying mechanisms and functions assumed. We found that very few mechanisms were explained; in most cases, the authors limited their analyses to hypotheses on how the intervention might have had an impact. Evaluations should focus on the intervention system and the underlying mechanisms, using comprehensive methodologies such as qualitative or mixed-methods studies (Altman et al. 2015; Cambon and Alla 2021) to inform the research and to help to create viable interventions.