Category-specific face prototypes are emerging, but not yet mature, in 5-year-old children

Abstract

Adults' expertise in face recognition has been attributed to norm-based coding. Moreover, adults possess separable norms for a variety of face categories (e.g., race, sex, age) that appear to enhance recognition by reducing redundancy in the information shared by faces and ensuring that only relevant dimensions are used to encode faces from a given category. Although 5-year-old children process own-race faces using norm-based coding, little is known about the organization and refinement of their face space. The current study investigated whether 5-year-olds rely on category-specific norms and whether experience facilitates the development of dissociable face prototypes. In Experiment 1, we examined whether Chinese 5-year-olds show race-contingent opposing aftereffects and the extent to which aftereffects transfer across face race among Caucasian and Chinese 5-year-olds. Both participant races showed partial transfer of aftereffects across face race; however, there was no evidence for race-contingent opposing aftereffects. To examine whether experience facilitates the development of category-specific prototypes, we investigated whether race-contingent aftereffects are present among Caucasian 5-year-olds with abundant exposure to Chinese faces (Experiment 2) and then tested separate groups of 5-year-olds with two other categories with which they have considerable experience: sex (male/female faces) and age (adult/child faces) (Experiment 3). Across all three categories, 5-year-olds showed no category-contingent opposing aftereffects. These results demonstrate that 5 years of age is a stage characterized by minimal separation in the norms and associated coding dimensions used for faces from different categories and suggest that refinement of the mechanisms that underlie expert face processing occurs throughout childhood.

Age‐Related Differences in Sensitivity to Facial Trustworthiness: Perceptual Representation and the Role of Emotional Development

“…Indeed, available evidence indicates that, although children represent faces in a multidimensional face space that has some adult-like characteristics at least from the age of 4 years (Jeffery et al, 2010), considerable refinement of this representation occurs throughout childhood. For example, separable representations of faces belonging to different categories defined by race, gender, and age emerge between 5 and 8 years of age (e.g., Short, Hatry, & Mondloch, 2011;Short, Lee, Fu, & Mondloch, 2014), and the representation of changeable facial traits like emotional expressions is also subject to critical changes across this same age range (Rodger et al, 2015). Other studies investigating identity discriminations have shown that, from 7 years onward, there are no differences between children and adults in the number of dimensions along which they represent faces, but children rely more heavily on one single dimension (e.g., hair cues or eye colour) when making similarity judgments, whereas adults use all dimensions equally (Nishimura et al, 2009;Pedelty, Levine, & Shevell, 1985).…”

Differential Trajectories in the Development of Attractiveness Biases Toward Female and Male Targets

“…Results also revealed that participants more often selected more average adult female faces than more average adult male faces, but that target sex difference was not consistently observed for 5-year-old and 9-year-old target faces [58]. This discrepancy might have occurred because children are in the process of forming more distinct representations for female and male faces and for adult and child faces [56,57]. Given early predominant experience with adult females for most children [18][19][20][21][22], the adult female face category average should be more established than the adult male face category average or child categories and thus most greatly influence averageness preferences for adult female faces.…”

“…Older children's increase in attention toward boys' attractiveness might be due to children's facial representations becoming more differentiated between 5 and 8 years of age. More specifically, 5-year-olds do not appear to have separate facial representations for female and male adult faces (or child and adult faces, or faces from different racial groups) [56]. [46,56] that are presumably attractive [12] and guiding processing of female and male targets' facial attractiveness (Figure 3).…”

“…More specifically, 5-year-olds do not appear to have separate facial representations for female and male adult faces (or child and adult faces, or faces from different racial groups) [56]. [46,56] that are presumably attractive [12] and guiding processing of female and male targets' facial attractiveness (Figure 3). Such a transition would explain why increases in age correlated with significant increases in children's attractiveness biases for male peers.…”

Orienting Toward Face‐Like Stimuli in Early Childhood

“…Changes in face‐processing ability sometimes follow nonlinear developmental trajectories (e.g., Chung & Thomson, ; Leonard, Karmiloff‐Smith, & Johnson, ; Mondloch, Dobson, Parsons, & Maurer, ; Mondloch, Le Grand, & Maurer, ; Short, Lee, Fu, & Mondloch, ). Moreover, there is evidence both for and against qualitative shifts in face perception ability during childhood (see Want, Pascalis, Coleman, & Blades, ), and a transient disruption during adolescence (Carey, Diamond, & Woods, ; Diamond, Carey, & Back, ; Thomas, De Bellis, Graham, & LaBar, ) possibly due to pubertal hormones (see Scherf, Behrmann, & Dahl, ).…”