*3.2. Testing for the Proposed Model*

The analysis results of SPSS macro PROCESS are presented in Table 2, which consists of four parts: Model 1, Model 2, conditional indirect effect analysis of Model 1, and conditional direct effect analysis of Model 2. Model 1 was used to test the effects of parental monitoring on children's escape motivation (part of H2), and the interaction between parental monitoring and children's shyness on children's escape motivation (H4), after controlling for age and gender. Model 2 examined the effects of parental monitoring on children's PMPU (H1), children's escape motivation on children's PMPU (part of H2), and the interaction between parental monitoring and children's shyness on children's PMPU (H3).


**Table 2.** Bootstrap test on moderated mediation effect.

Note. Bootstrap sample size = 5000. SE = standard error, LL = low limit, CI = confidence interval, UL = upper limit. <sup>+</sup> *p* < 0.10. \* *p* < 0.05. \*\* *p* < 0.01. \*\*\* *p* < 0.001.

The conditional indirect effect analysis of Model 1 tested the effects of parental monitoring at its mean, plus one, and minus one standard deviation on children's escape motivation at the mean of shyness. The conditional direct effect analysis of Model 2 tested the effects of parental monitoring at its mean, plus one standard deviation, and minus one standard deviation on children's PMPU at the mean of the shyness. According to Model 1 (*F* = 5.96, R<sup>2</sup> = 0.05, *p* < 0.001) and Model 2 (*F* = 65.74.45, R2 = 0.41, *p* < 0.001), after controlling for gender and age, parental monitoring positively predicted children's PMPU (β = 0.078, *p* < 0.05), supporting H1 (see Figure 2). Parental monitoring positively predicted children's escape motivation (β = 0.101, *p* < 0.05), and children's escape motivation positively predicted children's PMPU (β = 0.612, *p* < 0.001), supporting H2.

The interaction of parental monitoring and shyness showed significant effects on children's escape motivation (β = 0.102, *p* < 0.05). Thus, H4 was supported. This finding suggests that the relation between parental monitoring and children's escape motivation was moderated by children's level of shyness (see Figure 3). In addition, two of the three conditional indirect effects (based on the moderator values at the mean and at plus and minus one standard deviation) were positive and significantly different from zero (see conditional indirect effect analysis of Model 1). That is, according to the interaction of parental monitoring and children's shyness, the indirect effects of parental monitoring on children's escape motivation were stronger when children's shyness level was moderate to high, but lower when children's shyness level was low.

**Figure 2.** Moderation effects of shyness in the mediation model. All values shown are standardized coefficients. <sup>+</sup> *p* < 0.10. \* *p* < 0.05. \*\*\* *p* < 0.001.

**Figure 3.** Moderation effect of shyness in the relation between parental monitoring and children's escape motivation.

Furthermore, the interaction of parental monitoring and shyness showed marginally significant effects on children's PMPU (β = 0.063, *p* < 0.10). Therefore, H3 was supported. Two of the three conditional direct effects (based on the moderator values at the mean and at plus and minus one standard deviation) were positive and significantly different from zero (see conditional direct effect analysis of Model 2). These findings suggest that the relation between parental monitoring and children's PMPU was moderated by children's level of shyness (see Figure 4). The direct effects of parental monitoring on children's PMPU were higher when children's shyness was moderate to high, but lower when children's shyness was low. In conclusion, the above results indicated that parental monitoring affects children's PMPU through a moderated mediation path, with children's escape motivation as the mediator and children's shyness level as the moderator.

**Figure 4.** Moderation effect of shyness the relation between parental monitoring and children's PMPU.

#### **4. Discussion**

To reduce the negative impact of children's mobile phone use, parental monitoring has not achieved consistent results [45,48]; its underlying mechanism remains unclear. The present study examined a moderated mediation model and found that children's escape motivation partially mediated the association of parental monitoring and their PMPU. In addition, children's degree of shyness moderated the path from parental monitoring to their escape motivation and to PMPU.

#### *4.1. Escape Motivation Partially Mediates the Relation between Parental Monitoring and Adolescent PMPU*

Parental monitoring positively correlated with adolescent PMPU, which supports H1. This is consistent with the findings of previous studies regarding internet addiction [46]. Research has shown that adolescents are especially vulnerable to the negative impacts of increased mobile phone use, and parents hope to reduce these negative influences via mediation. Considering that teenage years are a critical period of learning and social development, most parents employ monitoring strategies to mediate their children's mobile phone use. However, research findings suggest that parental monitoring often leads to unexpected results. Because of adolescents' desire for freedom and psychological reactance induced by restriction, they may be subjected to the "Pandora effect" [63,68,96]; as the strength of parental monitoring of mobile phone use increases, adolescents' mobile phone-use behaviors also increase, which can eventually lead to PMPU. Similar results were found in other areas of addiction, including adolescent internet addiction [97], internet dependency [98], and sexual behaviors [99]. From the perspective of the sociology of emotions, emotions serve as an important precursor to effective parental mediation. However, parental monitoring often results in the conflicts between parents and child, causing negative emotions. The model of compensatory internet use suggests that internet use is viewed as a compensatory means to escape the reality. An individual with relatively low overall happiness tends to relieve negative emotions and escape from real-life problems via mobile phone use [100–102]. Moreover, in the family environment, whether the parents' supervision is effective or not partially depends on their own behaviors. According to Bandura's social cognitive theory, children observe the behaviors of others around them and are especially prone to observing, and imitating their parents' behaviors [103]. It has been found that parents' looking down at their own mobile phone (parent phubbing) in the process of communication with their children will not only aggravate children's addiction [104], but also affect children's attitude towards self-control mobile phone use [105]. Therefore, if parents want to achieve efficient monitoring results, they should control their own mobile phone-use behaviors. In general, although parental monitoring aims to improve children's mobile phone-use behaviors, it is often ineffective or leads to undesirable outcomes.

In addition, as we hypothesized, escape motivation mediated the relation between parental monitoring and adolescent PMPU, which supports H2. This result is consistent with similar studies. One study found that escape motivation mediated the predictive effect of negative emotions on PMPU [67]. When individuals face real-life struggles, escape motivation can prompt them to compensate through video games and/or the internet, which can eventually lead to video game or internet addiction [54,106,107]. Furthermore, Erikson [108] proposed that there is a developmental issue in every psychosocial stage of human development; adolescence is a crucial period for identity development, as well as a time when psychological reactance peaks. To adolescents, parental monitoring acts as a restriction of freedom, which could induce their escape motivation. In addition, parental monitoring often creates parent-child conflict, which could cause adolescents to develop negative emotions, thus leading to escape motivation.

### *4.2. Shyness Moderates Both the Relations of Parental Monitoring with Adolescent Escape Motivation and Adolescent PMPU*

The impact of parental monitoring on adolescent PMPU differs across individuals. The present study found that adolescent shyness level moderated the relation between parental monitoring and adolescent escape motivation, and between parental monitoring and adolescent PMPU, which supports H4 and H3. As children's shyness level increased, increases in parental monitoring strengthened their escape motivation and PMPU. This could be explained by the fact that shy individuals rely more on mobile phones to socialize, and parental monitoring can cause them to generate more negative reactions, such as psychological reactance and feelings of insecurity; this in turn perpetuates their escape motivation and exacerbates PMPU. There are three possible reasons why shy individuals rely more on mobile-phone socialization. First, shyness can be related to social anxiety; to avoid the embarrassment and discomfort elicited by face-to-face interactions, shy individuals tend to socialize via the internet, thus increasing internet use behaviors that can lead to internet and mobile-phone addiction [83,109]. Second, shy individuals often avoid occasions that expose them to evaluation [110]. Internet and mobile phone interactions can disguise their identity and thus protect them from others' evaluations. Third, shyness that originates from social anxiety can expose individuals to psychological challenges [111]. To mitigate and overcome these challenges, shy individuals tend to avoid face-to-face interactions, devote themselves to internet use, and achieve satisfaction through online interactions. Overall, when their parents employ monitoring strategies, shy adolescents might feel insecure and avoid being evaluated, which prompts them to escape reality via mobile phone use.

#### *4.3. Limitation and Implication*

The present study has a few limitations. First, our data are cross-sectional, and thus cannot infer strong causational relationships. Experimental or longitudinal designs could be used to further prove the relations between these variables. Second, all of our data came from adolescents' subjective responses. Although our measures have relatively high reliability/validity, the addition of responses from other sources (such as parents) would make our results more persuasive. Data of parental monitoring were obtained from children's self-report, but not from their parents' reports due to the limitation of our research conditions. In future research, obtaining data of parental monitoring from parents will help to reduce potential bias. Third, the findings in this study are in the context of Chinese culture, and its generalization to other culture should be made with caution. In order to avoid the negative effects of mobile phones, many parents in China prohibit children from bringing mobile phones to school. Using mobile phones at home is also often restricted. In comparison to children in other cultural contexts, Chinese children might have less freedom to use mobile phones. Moreover, studies on parental monitoring and children's PMPU have yielded different results under different cultural and national contexts (such as Turkey and Germany) [19,47]. Therefore, future studies can explore the effects of cultural differences and cultural contexts on the effect of parental monitoring on children's PMPU. Finally, future research should involve more schools and students to explore the differences between children in different developmental stages, such as early adolescence (12–13 years) and late adolescence (16–18).

Despite the above limitations, the contributions of the present study are relevant to educators, parents, and adolescents. First, our study results found that parental monitoring positively predicts adolescents' PMPU. However, as the forms of online activities increase and the access to the internet becomes easier, parents are more likely to use monitoring strategies [20]. Moreover, parental monitoring is the most direct mediation method and, therefore, the most convenient for parents [18]. One study points out parents' greater tendency to monitor their child's mobile phone-use behaviors when their use increases [46]. When parental monitoring increases children's mobile phone use, parental monitoring in turn increases, leading to a maladaptive cycle. Parents and educators should be cautious and optimize the use of monitoring strategies to control adolescent mobile phone use. Second, the present study found that parental monitoring positively predicted adolescents' escape motivation, which predicted their PMPU. Third, the effect of parental monitoring on adolescents differed across temperaments. When parents strengthen their monitoring, shy adolescents are more likely to display escape motivation and develop problematic mobile phone-use behaviors. Parents should adopt appropriate mediation strategies according to their child's temperament.

### **5. Conclusions**

Parental monitoring positively predicts children's PMPU, and this predictive effect is partially mediated by children's escape motivation. Children's level of shyness moderates the relation between parental monitoring and children's escape motivation, and the relation between parental monitoring and children's PMPU, Thus, increasing the strength of parental monitoring can lead to an increase in escape motivation and PMPU among shy adolescents.

**Author Contributions:** Conceptualization, X.F. and J.L.; Formal analysis, X.F. and F.J.; Funding acquisition, R.-D.L.; Investigation, R.Z., F.J. and J.W.; Project administration, R.-D.L.; Supervision, R.-D.L.; Validation, R.-D.L.; Writing—review and editing, X.F., J.L., R.-D.L. and Y.D. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded by National Social Science Fund of China: 17BSH102.

**Conflicts of Interest:** The authors declare no conflict of interest.

#### **References**


*Int. J. Environ. Res. Public Health* **2020**, *17*, 1487


© 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).

International Journal of *Environmental Research and Public Health*
