Individual differences in the social evaluation of 6-month-old infants

Abstract: Social evaluation refers to the capacity of a human being to assess the behavior and intention of others in a social context. As social beings, humans inhabit a profoundly interconnected world characterized by unceasing interpersonal interactions. Under this background, the manner in which individuals evaluate their peers acts as the foundation for comprehending the world. In particular, early social assessment serves as a precursor variable in the development of moral and prosocial behaviors in subsequent years. It is a pivotal factor in shaping an individual’s future prosocial tendencies. On the one hand, social evaluation aids in identifying suitable social companions, avoiding inappropriate or hazardous individuals, and making judicious decisions. On the other hand, it assumes a pivotal role in kindling an individual’s prosocial inclinations, guiding prudent behavioral choices, molding prosocial conduct, and fostering moral maturation.
Social evaluation capacity among adults primarily manifests through their quick acquisition of meaningful insights from the emotional, behavioral, and postural cues of others, enabling them to formulate corresponding assessments and behavioral responses. Similarly, infants exhibit the capacity to discern behavioral cues exhibited by others during social interactions, extrapolating insights into their motives and intentions and making apt assessments.
In 2007, Hamlin et al. published a study in Nature that reported that 6-month-old infants possessed social evaluative skills, responding differently to the “helping” and “hindering” behaviors of individuals during social interactions and showing greater preference for helpers (prosocial agents). Since then, researchers have continuously challenged the replicability of this result. In the present study, we used the classic “helper–hinderer” choice paradigm of Hamlin et al. (2007) and a violation of the expectation paradigm to examine the choice preferences and gaze duration of Chinese infants (age: 6.32 ± 0.34 months; total of 179, 86 were girls) in a social evaluation task, and their relationship with the temperament of infants. The results of the present study showed that the gaze duration of infants was significantly higher when a third party approached the hinderer than when a third party approached the helper in an expectation violation task. However, infants did not show a preference for the helper in the behavioral choice task as reported by Hamlin et al. Infants who scored higher in the surgency dimension of temperament were more likely to choose “helper” in the manual choice task.
In general, the results suggested that 6-month-old infants may already exhibit social evaluation ability to understand the behavior of others and infer their evaluation. However, individual differences are observed in this ability, which may be related to the temperament of infants.