Facial symmetry and the perception of beauty

Abstract

Evolutionary, as well as cultural, pressures may contribute to our perceptions of facial attractiveness.Biologists predict that facial symmetry should be attractive, because it may signal mate quality. We tested the prediction that facial symmetry is attractive by manipulating the symmetry of individual faces and observing the effect on attractiveness, and by examining whether natural variations in symmetry (between faces) correlated with perceived attractiveness. Attractiveness increased when we increased symmetry, and decreased when we reduced symmetry, in individual faces (Experiment 1), and natural variations in symmetry correlated significantly with attractiveness (Experiments 1 and lA). Perfectly symmetric versions, made by blending the normal and mirror images of each face, were preferred to less symmetric versions of the same faces (even when those versions were also blends) (Experiments 1 and 2). Similar results were found when subjects judged the faces on appeal as a potential life partner, suggesting that facial symmetry may affect human mate choice. We conclude that facial symmetry is attractive and discuss the possibility that this preference for symmetry may be biologically based.The question of what makes a face attractive, and whether our preferences come from culture or biology, has fascinated scholars for centuries. Variation in the ideals of beauty across societies and historical periods suggests that standards of beauty are set by cultural convention. Recent evidence challenges this view, however, with infants as young as 2 months of age preferring to look at faces that adults find attractive (Langlois et aI., 1987), and people from different cultures showing considerable agreement about which faces are attractive

Appearance of symmetry, beauty, and health in human faces

“…The present results are consistent with previous findings that showed a poor relationship between attractiveness and symmetry in adult faces (Knowner, 1996) or with infants (Samuels et al, 1994). Sex of face did not explain the present results nor previously published findings, regardless of whether or not those other findings are inconsistent with ours (Grammer & Thornhill, 1994;Rhodes et al, 1998). Moreover, sex of participant does not explain the poor relationship between attractiveness and symmetry; in preliminary perusal of the data we found no significant trends with participant sex.…”

“…In human interactions, the face is a principle source of communication (speech and facial expressions) and inspection. However, the symmetry status in faces is not clear considering previous evidence that human faces are both structurally and functionally asymmetric (Zaidel, Chen, & German, 1995) and inconsistent published reports regarding the relationship between symmetry and attractiveness (Grammer & Thornhill, 1994;Knowner, 1996;Rhodes, Proffitt, Grady, & Sumich, 1998;Samuels, Butterworth, Roberts, Graupner, & Hole, 1994). Moreover, animals have largely left-right symmetrical brains whereas humans do not.…”

“…Studies that have used normal, head-on photographs and created symmetrical left-left and right-right faces have reported a weak relationship between beauty and symmetry (Knowner, 1996;Samuels et al, 1994) whereas studies that manipulated photographs through morphing or digital smoothing have reported a strong relationship (Grammer & Thornhill, 1994;Rhodes et al, 1998). Small infants, for example, are more interested in beautiful faces than they are in symmetrical faces (Samuels et al, 1994) and this suggests that from birth the human brain is neuronally wired to attend to features related to beauty rather than to features related to symmetry in faces.…”

Concordant preferences for opposite–sex signals? Human pheromones and facial characteristics

“…While the precise roles of environment and genetic influences are equivocal, suggested visual signals of heritable mate quality include body and face symmetry Rhodes et al 1998;Perrett et al 1999;Jones et al 2001;, masculine and feminine face shapes (Perrett et al 1998;Penton-Voak et al 1999;Penton-Voak & Perrett 2000) and body shape (Singh 1993;Tovee et al 1999). Non-visual signals include body odour (Gangestad & Thornhill 1998;Rikowski & Grammer 1999;Thornhill & Gangestad 1999;Singh & Bronstad 2001) and vocal characteristics (Collins 2000;Hughes et al 2002).…”

Higher-level mechanisms detect facial symmetry

“…Furthermore, symmetry detection is not restricted to low-level visual processing, contributing to high-level processes of object recognition (e.g. with symmetric image features signalling symmetric objects ;Biederman 1987) and face perception (Rhodes et al 1998;Simmons et al 2004). These observations suggest that higher-level coding mechanisms, which respond to abstract properties of objects, may also play a role in symmetry detection (see also Wilson & Wilkinson 2002).…”