“The cheerleader effect” refers to the increase in attractiveness that an individual face experiences when seen in a group of other faces. It has been proposed that the cheerleader effect occurs because (a) the visual system rapidly summarises a group of faces into an ensemble representation, (b) which is hypothesised to be highly attractive because of its average facial characteristics, and (c) observers remember individual faces to be more alike the ensemble representation than they were, due to hierarchical structure of visual working memory. Across three experiments, we investigated whether the cheerleader effect is consistent with hierarchical encoding, by asking observers to give attractiveness ratings to the same target faces shown in groups and alone. Consistent with hierarchical encoding, the largest attractiveness increases of 1.5–2.0% occurred when target faces were presented in groups of faces that could be mentally summarised to create an ensemble representation with average facial characteristics. Surprisingly, smaller cheerleader effects still occurred in conditions that were incompatible with hierarchical encoding (i.e., groups with non-human images). Together, these results offer only limited evidence for the role of hierarchical encoding in the cheerleader effect, suggesting that alternative mechanisms must be explored in future research.

Faces of individuals with African and European heritage (henceforth referred to as Black and White respectively) feature two major differences: those of skin tone and morphological characteristics. Although considerations of perceived race are important to various psychological subdisciplines, to date the relative influence of morphological versus photometric characteristics has not been investigated. We attempted to influence the perceived racial typicality of a central target face by manipulating perceived skin tone using the well-known lightness contrast illusion. As expected, ratings of skin tone were influenced by surround faces, yet ratings of perceived racial typicality were not, suggesting a dissociation between the two judgments. Surprisingly, skin tone contributes little to perceived race, leaving facial morphology as the dominant cue. These results may shed light on failures to find effects of racial typicality in studies of prejudice where judgments were based on photographs with altered skin tone alone.

Trustworthiness is assumed to be processed implicitly from faces, despite the fact that the overwhelming majority of research has only involved explicit trustworthiness judgements. To answer the question whether or not trustworthiness processing can be implicit, we apply an electroencephalography fast periodic visual stimulation (FPVS) paradigm, where electrophysiological cortical activity is triggered in synchrony with facial trustworthiness cues, without explicit judgements. Face images were presented at 6 Hz, with facial trustworthiness varying at 1 Hz. Significant responses at 1 Hz were observed, indicating that differences in the trustworthiness of the faces were reflected in the neural signature. These responses were significantly reduced for inverted faces, suggesting that the results are associated with higher order face processing. The neural responses were reliable, and correlated with explicit trustworthiness judgements, suggesting that the technique is capable of picking up on stable individual differences in trustworthiness processing. By demonstrating neural activity associated with implicit trustworthiness judgements, our results contribute to resolving a key theoretical debate. Moreover, our data show that FPVS is a valuable tool to examine face processing at the individual level, with potential application in pre-verbal and clinical populations who struggle with verbalization, understanding or memory.

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Pre-print Version 1 (October 2019): *This manuscript is undergoing peer-review and will be updated periodically* Total Word Count: 3850 approx.