Academic achievement is a multifaceted construct that can be defined in broad and narrow aspects. Marsh and McCallum defined it broadly as the extent to which students achieve the objectives or goals of their educational institution or program [1]. In contrast, Hattie defined it narrowly as the progress that students make in their academic studies, demonstrated through their performance on tests, exams, and other assessments [2]. Many researchers have adopted the narrow definition, focusing on test scores in specific subjects [3,4,5]. In China, academic achievement is often measured by test scores in Chinese, Math, and English [6, 7]. Therefore, academic achievement in this study refers to students’ test scores in these subjects. Academic achievement holds substantial importance not only for students’ future prospects but also serves as a critical indicator for evaluating the effectiveness of national educational systems [8].
Peer relationships have been recognized as influential factors in adolescents’ academic achievement [9]. Peer relationships refer to the social interactions and connections that individuals establish with their peers, including interpersonal relationship, social emotion, communication interaction [10]. They can have a profound impact on students’ academic outcomes, as peers can serve as sources of both positive and negative influence. Positive peer relationships have been associated with higher levels of academic achievement, while negative peer relationships can hinder students’ academic progress [11].
Learning motivation and learning engagement are two psychological constructs that have been extensively studied in relation to academic achievement [12]. Learning motivation encompasses the internal drive and inclination to participate in learning activities, which can be classified into two main categories: intrinsic motivation and extrinsic motivation [13]. Intrinsic motivation stems from personal interest, curiosity, and the inherent satisfaction derived from the learning process itself, while extrinsic motivation is driven by external factors such as rewards, grades, or social recognition [14]. Learning engagement encompasses the active involvement, effort, and persistence that individuals exhibit during the learning process, categorized into three components: vigor, dedication, and absorption [15]. Vigor is often used to describe an individual’s level of enthusiasm, engagement, and persistence in their studies. Dedication refers to an individual’s commitment and devotion to their academic pursuits. Absorption refers to an individual’s deep focus and concentration on what is studied [16]. Both learning motivation and learning engagement have been found to exhibit a positive correlation with academic achievement. For example, Wentzel suggested that learning motivation plays a positive role in academic achievement [17]. Similarly, Li et al. observed a noteworthy positive association between academic motivation and mathematics achievement among junior high school students [18]. Liem and Martin posited that school engagement has a positive impact on academic performance [19]. The findings highlight the importance of considering both learning motivation and learning engagement in understanding academic achievement.
Despite scholars proposing the influence of these factors on academic achievement, the specific mechanisms through which peer relationships influence academic achievement via learning motivation and learning engagement remain underexplored. To address this research gap, the primary objective of the current study is to investigate the interactive effects of peer relationships, learning motivation, and learning engagement on academic achievement, thereby providing a holistic comprehension of the interplay between these factors. Furthermore, this study endeavors to examine the chain mediating roles of learning motivation and learning engagement in the association between peer relationships and academic achievement among junior high school students. By examining these mediating pathways, this study seeks to elucidate the underlying mechanisms by which peer relationships impact academic outcomes. This study differs from those in investigating the chain mediating roles of learning motivation and learning engagement in the association between peer relationships and academic achievement within a unified conceptual framework, contributing to a deeper understanding of the factors that shape students’ academic success.
The self-system model of motivational development (SSMMD) serves as a conceptual framework for this study. Proposed by Connell and Wellborn [20] and supported by Skinner et al. [21], the SSMMD is rooted in the self-determination theory [22] and emphasizes the importance of individuals’ intrinsic motivation and psychological needs for autonomy, competence, and relatedness [23]. The SSMMD comprises four interconnected components: social context, self-system, action, and developmental results. The social context, consisting of peers, teachers, and parents, shapes an individual’s self-system. It is within this social context that an individual’s self-beliefs, motivation, and engagement in activities are developed. The self-system, as a relatively stable personal resource, is influenced by long-term interactions with the surrounding context and can effectively predict the level of involvement in activities. This level of involvement, in turn, directly influences various aspects of an individual’s development, including behavior and academic performance [24]. The SSMMD presents a linear developmental pathway, where the social context influences the self-system, which then influences actions and subsequently developmental outcomes. In this study, we utilize the SSMMD framework to explore the relationship between peer relationships, learning motivation, learning engagement, and academic achievement. The relationship between the four variables and SSMMD can be elaborated as follows: Peer relationships, as a component of the social context, shapes an individual’s self-beliefs, which significantly influences their learning motivation. Students who possess higher levels of learning motivation are more likely to get active engagement in learning activities (as a component of the action), and impact their academic achievement positively (as a developmental outcome) [25]. Based on this model, this study hypothesizes that peer relationships (as a social context factor) may influence adolescents’ learning motivation (as a self-system factor), which in turn affects their learning engagement (as individual action), ultimately resulting in a positive impact on academic achievement (as developmental outcomes). This theoretical model in the study is visually represented in Fig. 1.
The proposed theoretical model
Peer relationships and academic achievement
Previous research has consistently demonstrated the positive influence of peer relationships on academic achievement [26]. Several studies have examined the positive impact of peer relationships on overall academic achievement. For instance, Wentzel noted that peers’ support in homework was positively related to academic achievement [17]. Jacobson and Burdsal found that positive peer influence in middle schools predicted higher academic achievement [27]. In a longitudinal study, Gallardo et al. (2016) demonstrated the positive influence of peer relationships on mid-adolescents’ academic achievement [11]. Additionally, research has investigated the positive effects of peer relationships on academic achievement in specific subjects. For example, Li et al. reported a significantly positive effect of peer relationships on the mathematics achievement of junior high school students [18]. Li et al. (2020) identified a significantly positive connection between peer relationships and science literacy among 596 ethnic minority junior school students in China [28]. Moreover, previous studies have suggested that the positive impact of peer relationships on academic achievement increases with grade level [29] and that same-gender peer relationships are particularly important in predicting academic achievement [19]. Overall, these findings emphasize the critical role of positive peer relationships in academic achievement, highlighting that adolescents who cultivate supportive relationships with their peers are more inclined to achieve success in their academic pursuits. On the basis of this, the following hypothesis is proposed.
H1: Peer relationships are positively correlated with academic achievement.
Learning motivation as a mediator
Peer relationships have been demonstrated to have a significant influence on learning motivation [11]. Positive peer relationships can enhance students’ motivation in learning by providing support, encouragement, and a sense of belonging. For example, Li et al. have indicated that positive peer relationships could encourage students to strive towards predetermined learning goals [30]. Similarly, Kuo et al. have shown that regular peer interaction could increase students’ motivation and interest in learning [31]. Wentzel et al. conducted a questionnaire survey involving 240 participants, and found that adolescents who receive positive support from their peers are more prone to exhibit higher levels of motivation [32]. In a study by Huangfu et al. it was observed that peer support in the context of chemistry education had a significant positive impact on students’ continuing motivation in chemistry [33]. Conversely, negative peer relationships can lead to decreased motivation. For instance, Juvonen and Graham found that students who experienced bullying, as a form of negative peer relationship, reported lower levels of motivation to engage in academic tasks [34]. Similarly, Wentzel et al. revealed that peer rejection, as another form of negative peer relationship, was associated with lower levels of intrinsic motivation in students [35]. These finding underscore the crucial role of peer relationships in influencing students’ motivation in specific academic domains.
Furthermore, learning motivation has been found to have a positive correlation with academic achievement [36]. Students who possess high levels of motivation to learn tend to excel in classroom activities, put forth great effort to complete their learning assignments, and achieve their academic achievement [37]. Researchers have demonstrated that learning motivation, as a potential mechanism is associated with perceived academic achievement [38]. Moreover, intrinsic motivation has been found to have a positive correlation with students’ grades, while extrinsic motivation shows a negative association with academic outcomes [39]. In addition, researchers have shown that learning motivation exerts both direct and indirect influences on students’ academic achievement through learning activities [40]. Peer interactions have also been emphasized as influential factors in adolescent learning motivation and subsequent learning outcomes [41]. Li et al. highlighted the mediating role of learning motivation in the relationship between peer relationships and mathematics achievement [18]. Although the study focused on Zhuang ethnic minority students in China and limited the academic achievement to mathematics, it provides valuable insights and direction for the mediation hypothesis in this research. Based on these findings, the following assumptions are proposed:
H2: Peer relationships are positively correlated with learning motivation.
H3: Learning motivation is positively correlated with academic achievement.
H4: Learning motivation mediates the association between peer relationships and junior high school students’ academic achievement.
Learning engagement as a mediator
Research has consistently shown that peer relationships have an impact on students’ learning engagement [42]. For instance, Kiefer et al. have proposed that peer support may help middle school students improve their learning engagement [43]. Besides, Research has demonstrated that both academic and emotional support from peers can enhance students’ learning engagement [44]. Lee et al. have claimed that peer interaction can help students sustain their engagement in e-learning [45]. In addition, Yuan and Kim have suggested that peer appraisal in peer interactions can affect teenagers’ cognitive and emotional involvement [46].
Learning engagement is considered to be an important factor that affects students’ academic achievement [12]. High levels of learning engagement allow students to devote more time to learning activities and ultimately achieve better academic outcomes [47]. Liem and Martin found that active participation and investment in learning activities positively predict academic success [19]. Wang et al. further supported this by demonstrating that higher levels of classroom engagement are associated with better academic performance [4]. Additionally, Saqr et al. highlighted the longitudinal effects of engagement, showing that sustained high levels of engagement lead to improved academic outcomes over time [48]. Taken together, these recent studies underscore the critical role of student engagement in fostering academic achievement.
Learning motivation has been demonstrated to have a significant impact on students’ engagement in learning activities [49]. When students are motivated to learn, they are more likely to set ambitious goals and actively participate in their learning activities [50]. Research has consistently found a positive relationship between learning motivation and engagement [25, 41]. For instance, a study by Froiland and Worrell explored the role of motivation in student engagement and found that intrinsic motivation, which stems from personal interest and enjoyment, was positively associated with higher levels of engagement [51]. Similarly, a study by Huang and Yang highlighted the importance of learning motivation, where students feel a sense of desire and enjoyment in their learning, in promoting engagement [52]. The self-system model of motivational development suggests that social contexts, including interactions with peers, can impact students’ self-systems, such as their motivation and self-efficacy in learning. When students’ self-systems, including learning motivation, are strengthened, they are more likely to engage in learning activities, leading to improved academic outcomes, such as academic achievement. Therefore, based on the aforementioned research, it is postulated that peer relationships can promote academic achievement by enhancing students’ motivation and engagement in learning activities. Hypotheses were derived from the aforesaid analysis:
H5: Peer relationships are positively correlated with learning engagement.
H6: Learning motivation is positively correlated with learning engagement.
H7: Learning engagement is positively correlated with academic achievement.
H8: Learning engagement mediates the association between peer relationships and junior high school students’ academic achievement.
H9: Learning motivation and learning engagement play a chain mediating role in the association between peer relationships and junior high school students’ academic achievement.
