Trust judgment refers to an individual’s assessment of whether someone and their viewpoints are trustworthy based on various cues in specific situations. Children’s trust judgments based on faces undergo developmental changes throughout childhood and are crucial for self-protection and social adaptation, garnering extensive attention from researchers. The research on children’s trust judgments primarily utilizes the trust Game, the “conflicting sources” paradigm, and its related variations. This review aims to outline the processes, development, and underlying mechanisms of children’s trust judgments based on facial features between the ages of 3 and 12, in order to better understand the impact of facial features on children’s trust judgments.
Empirical studies have been reviewed to identify facial features that influence children’s trust judgments. These features primarily focus on seven aspects of faces: gender, race, attractiveness, trustworthiness, competence, dominance, and expressions. First, Children tend to trust strangers who resemble themselves (e.g., same gender or same race) and exhibit positive facial features (e.g., positive expressions, high facial attractiveness, and trustworthiness). Second, trust judgments based on facial features are modulated by factors such as informants’ epistemic characteristics, task requirement, and cultural context.
This review outlines the development of children’s trust judgments based on facial features and potential mechanisms, proposing a model (see Figure 1) based on previous research. This model addresses a major issue in the literature, the lack of clarity in the process of trust judgments based on facial features. Many studies have conflated trust judgments with trustworthiness judgments, leading to the confusion of concepts such as feature judgments and trust judgments, which can be misleading to researchers. In the model proposed in this review, the process is divided into two stages: face-feature-trust judgment. The face-feature process relates to the formation of first impressions and influences the feature-trust judgment process.
Children’s trust judgments based on facial features exhibit trends in early childhood that are similar to those of adults, suggesting common mechanisms between children and adults from an evolutionary perspective. However, the ongoing development throughout childhood indicates the presence of unique developmental mechanisms. This development in trust judgments based on facial features in childhood is accompanied by the development of facial perception, general cognitive abilities, and accumulated social experience. In light of this, this review summarizes the following mechanisms: perceptual foundation, emotion and affect, general cognitive abilities, and social experience. First, from an evolutionary perspective, it explains the facial features preferred by humans from a reproductive standpoint, while from a cognitive perspective, it interprets the facial features that align with individual perceptual processing as a means of conserving cognitive resources. Both fundamentally explore the influence of facial perceptual foundations on trust judgments. Second, facial features can trigger emotions in the trustee, and the emotions activated by faces impact trust judgments through two pathways: cognitive reasoning and memory. Third, general cognitive abilities primarily come into play during the feature-trust judgment process. For children to successfully make trust judgments about different faces, they need to remember information provided by unfamiliar individuals with different faces and understand the mental states of others. When different task demands are involved, children must also be able to flexibly switch and match between task requirements and facial features. This process places certain demands on children’s general cognitive abilities, such as memory, language, and executive functions. The continuous development of trust judgments based on facial features in children may also reflect improvements in general cognitive mechanisms, including attention, explicit memory capacity, and task strategy abilities. Third, general cognitive abilities primarily come into play during the feature-trust judgment process. For children to successfully make trust judgments about different faces, they need to remember information provided by unfamiliar individuals with different faces and understand the mental states of others. When different task demands are involved, children must also be able to flexibly switch and match between task requirements and facial features. This process places certain demands on children’s general cognitive abilities, such as memory, language, and executive functions. The continuous development of trust judgments based on facial features in children may also reflect improvements in general cognitive mechanisms, including attention, explicit memory capacity, and task strategy abilities. Fourth, in the process of social interaction, children accumulate knowledge about faces with different characteristics and learn about the associations between faces with different characteristics and social behaviors. This process of social learning is crucial for trust judgments based on facial features.
Finally, the review suggests feasible directions for future research based on existing studies. Methodologically, future research should focus on the impact of facial materials and research designs on research outcomes. In terms of developmental characteristics, future research should delve deeper into the trust judgment features of children of different age groups, contributing to the understanding of the developmental processes and mechanisms of trust judgments based on faces.
