At the age of 4, children undergo major changes in their mentality and their potential starts to develop rapidly; these changes result in new psychological characteristics, such as fearlessness, seamless communication, independence, and selfconfidence,

as well as varying levels of quietness and activity. They evidently become more acquainted with their immediate surroundings and become more active, flexible, and persistent as they accumulate additional experiences. According to Kaya and Deniz (2020), the age of 4 years, which is the formal age for entering kindergarten, represents a peak in development.

Therefore, many researchers include 4-year-old children as their research sample.

When young children exhibit fearlessness, effective communication, self-reliance, and self-confidence, these manifestations collectively indicate social competence. Achieving social competence is regarded as a major developmental milestone for young

children. During early childhood, deficits in social competence are strongly associated with externalized behaviors, such as anger, aggression, selfishness, and hostility, and internalized behaviors, such as depression, anxiety, isolation, and dependency (Huber et al., 2019). Therefore, social competence plays a pivotal role in the psychological development of children.

       Many studies have indicated that the family environment of children affects their social competence (Xie et al., 2022), including their cognitive development (Razza et al., 2010) and social and emotional development (Baker, 2017). Social competence stems from long-term development, age-related changes, and environmental requirements (Quinn & Hennessy, 2010). According to Taborsky (2021), the presence of a family environment that is conducive to sociality can help foster individuals with increased social competence, thus indicating the effect of family environment on social competence.

         Temperament affects social competence, as reported by Dollar et al. (2018), who indicated that negative emotional traits such as anger at the age of 2 years influence social skills at the age of 7 years, with positive emotional temperament exerting an

opposite effect. Eisenberg et al. (2003) argued that the presence of effortful control temperament enables young children to make more positive choices when confronted with challenges such as obedience and empathy. According to Huber et al. (2019), young children with extraversion and effortful control temperament tend to exhibit reduced internalized and externalized behavioral problems. Because these externalized behavioral problems impede social interactions and cooperation, they inevitably affect social competence.

        According to the aforementioned analysis, both family environment and temperament affect social competence. Therefore, temperament may play a moderating role in the relationship between family environment and social competence. Previous Taiwanese studies have included young children as research samples to examine the correlations between family environment, social competence, and temperament. For instance, Chen (1996) examined the correlations between early childhood,

temperament, and social competence by using statistical methods such as Pearson’s correlation and canonical correlation analyses. Lue (2010) investigated the correlations between parental emotional socialization behaviors, emotional regulation, and peer interactions in young children and analyzed the differences between fathers and mothers in this context. However, few studies have investigated the moderating role of temperament in the relationship between family environment and social competence, thus necessitating further research regarding the correlations between these three variables. The findings of such research would guide parents in fostering an appropriate family environment and identifying the type of temperament that can act as an effective moderator. These findings may contribute to enhancing young children’s temperament and strengthening therelationship between family environment and social competence. They can also provide valuable insights for future research.

       In accordance with the literature, the following hypothesis was proposed: Effortful control temperament, extraversion temperament, and negative emotional temperament moderate the relationship between family environment and social competence. Data were collected from the Kids in Taiwan: National Longitudinal Study of Child Development & Care (KIT) database established by Chang (2021). Structured interviews were conducted to collect data regarding 48-month-old children from their main caregivers, yielding a total of 2,031 valid samples, including 1,029 boys (50.7%) and 1,002 girls (49.3%).

          In accordance with the afore entioned moderating model, data on three variables, namely, family environment, social competence, and temperament, were extracted from the KIT database. Initially, a cohort of 280 children aged 2–7 years underwent a pretest involving the three variables. The results of this pretest confirmed the reliability of the database. Because this study exclusively included 48-month-old children as the sample, retesting the reliability of the database was mandatory.

       Given that the three variables have clear dimensions, 100 individuals were randomly selected from the KIT database and partial least squares confirmatory factor analysis was conducted using SmartPLS (version 3.0), which is suitable for small samples (30–100 individuals). The results indicated that the three variables exhibited appropriate reliability.

          In this study, a moderating model of temperament was introduced. In this model, family environment serves as an exogenous variable, temperament serves as a moderating variable, and social competence serves as an endogenous variable. To identify a potential moderating effect, cross-product analysis was conducted. Specifically, family environment was multiplied by three temperaments. Identifying any cross-product reaching a significant level implied a moderating effect of temperament .

In this study, our first step was to test for normality. However, our results revealed a violation of the assumption of normal distribution. Given that this study involved a complex model, subsequent analyses were conducted through partial least squares structural equation modeling. The model was also adjusted for the gender of young children and the educational level of their parents. First, we used the unmeasured latent method construct proposed by Lindell and Whitney (2001) to investigate the effect of common method variance. The results indicated that common method variance did not constitute a serious problem. Second, we examined the goodness of fit value. The results revealed the suitability of both the measurement and structural models. Third, we tested the coefficients of each path. The results revealed significant positive correlations between the path coefficients of family environment to social competence, extraversion temperament, effortful control, and negative emotional temperament. Unlike negative emotional temperament, extraversion and effortful control temperament exhibited significant positive correlations with social competence.

         In terms of moderating effects, neither moderating effect 1 (family environment multiplied by extraversion temperament) nor moderating effect 3 (family environment multiplied by negative emotional temperament) played a significant role in the path to social competence. However, moderating effect 2 (family environment multiplied by effortful control temperament) played a significant role in the path to social competence, with a positive β value of .35. Therefore, when the score of effortful control temperament increased by 1 standard deviation, the correlation between family environment and social competence became stronger.

        Unlike extraversion temperament and negative emotional temperament, effortful control temperament moderates the relationship between family environment and social competence. Accordingly, the following recommendations should be considered. First, parents should foster an appropriate family environment to enhance the social competence of their children.

         Second, parents should focus on cultivating their children’s effortful control temperament. Third, kindergartens should create an environment conducive to effortful control temperament and social competence. Finally, future studies should focus on the observational indicator of conditional discipline as an independent latent variable and explore its relationship with other variables. Researchers should also integrate the internal and external factors influencing young children and explore their effects

on social competence.