Cosmetics as a Feature of the Extended Human Phenotype: Modulation of the Perception of Biologically Important Facial Signals

Shannon Stock,Sarah A Vickery,Nancy L Etcoff,David M House,Satoru Suzuki,Lauren E Haley

doi:10.1371/journal.pone.0025656

Abstract

Research on the perception of faces has focused on the size, shape, and configuration of inherited features or the biological phenotype, and largely ignored the effects of adornment, or the extended phenotype. Research on the evolution of signaling has shown that animals frequently alter visual features, including color cues, to attract, intimidate or protect themselves from conspecifics. Humans engage in conscious manipulation of visual signals using cultural tools in real time rather than genetic changes over evolutionary time. Here, we investigate one tool, the use of color cosmetics. In two studies, we asked viewers to rate the same female faces with or without color cosmetics, and we varied the style of makeup from minimal (natural), to moderate (professional), to dramatic (glamorous). Each look provided increasing luminance contrast between the facial features and surrounding skin. Faces were shown for 250 ms or for unlimited inspection time, and subjects rated them for attractiveness, competence, likeability and trustworthiness. At 250 ms, cosmetics had significant positive effects on all outcomes. Length of inspection time did not change the effect for competence or attractiveness. However, with longer inspection time, the effect of cosmetics on likability and trust varied by specific makeup looks, indicating that cosmetics could impact automatic and deliberative judgments differently. The results suggest that cosmetics can create supernormal facial stimuli, and that one way they may do so is by exaggerating cues to sexual dimorphism. Our results provide evidence that judgments of facial trustworthiness and attractiveness are at least partially separable, that beauty has a significant positive effect on judgment of competence, a universal dimension of social cognition, but has a more nuanced effect on the other universal dimension of social warmth, and that the extended phenotype significantly influences perception of biologically important signals at first glance and at longer inspection.

Highlights

First impressions based on facial appearance occur automatically, are difficult to overcome, and impact decision-making
Darwinian approaches posit that features of beautiful faces are important biological signals of mate value that motivate behavior in others, and have identified features such as averageness, symmetry and sexual dimorphism as key contributors to female facial beauty [5,6,7,10,11]
Analysis Our statistical analyses of makeup by inspection time were obtained from a linear mixed effects model with crossed random effects, similar to the model described by Baayen et al [33]

Summary

Introduction

First impressions based on facial appearance occur automatically, are difficult to overcome, and impact decision-making. Darwinian approaches posit that features of beautiful faces are important biological signals of mate value that motivate behavior in others, and have identified features such as averageness, symmetry and sexual dimorphism as key contributors to female facial beauty [5,6,7,10,11] It is less clear what visual facial attributes lead to rapid judgments of trustworthiness, competence, and likeability from the face. The ‘‘beauty halo’’ may provide a partial explanation, it is likely that cues from facial expressions (real or mimicked by the contours of natural features), and facial immaturity or maturity are important drivers, the first signaling friendly or hostile intent (positive emotion or anger), and the latter, the perceived ability to carry out one’s intentions [12,13,14] All such facial judgments occur quickly, reliably, and change little with inspection time, suggesting that they are effortless and automatic. Recent models of social cognition and decision-making distinguish between such fast operating, reflexive processes or ‘‘system 1 processes’’ and slower, deliberate, effortful, and reflective "system 2" processes [15,16]

Methods

Results

Conclusion