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A Sex Difference in Facial Contrast and its Exaggeration by Cosmetics

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This study demonstrates the existence of a sex difference in facial contrast. By measuring carefully controlled photographic images, female faces were shown to have greater luminance contrast between the eyes, lips, and the surrounding skin than did male faces. This sex difference in facial contrast was found to influence the perception of facial gender. An androgynous face can be made to appear female by increasing the facial contrast, or to appear male by decreasing the facial contrast. Application of cosmetics was found to consistently increase facial contrast. Female faces wearing cosmetics had greater facial contrast than the same faces not wearing cosmetics. Female facial beauty is known to be closely linked to sex differences, with femininity considered attractive. These results suggest that cosmetics may function in part by exaggerating a sexually dimorphic attribute-facial contrast-to make the face appear more feminine and hence attractive.
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1 Introduction
Though a widespread belief in the social sciences holds that standards of beauty are
arbitrary cultural conventions (Etcoff 1999), recent work has shown that our preferences
are at least partly based in biology, with evidence mounting for several biologically
based factors of attractiveness (Fink and Penton-Voak 2002; Rhodes 2006). Yet groom-
ing behaviors such as the application of facial cosmetics have largely not been linked
to these factors, and are still considered products of fashion (but see Ca
¨rdenas and
Harris 2006; Fink and Neave 2005; Law Smith et al 2006 for suggestions of possible
biological underpinnings). Use of cosmetics to beautify the face long predates the iden-
tification of these factors of attractiveness, which indicates that cosmetics were not
developed explicitly to manipulate these factors. However, it is possible that cosmetic
usage has evolved over time to exploit one or more of these factors. The study reported
here supports this perspective, by showing that cosmetics manipulate one of the
biological factors of beauty
ö
sexual dimorphism. Specifically, it is demonstrated that
cosmetics exaggerate a previously unknown sex difference in facial contrast.
Female skin has been observed and measured to be lighter than male skin, provided
the males and females being compared are from the same ethnic group (Darwin 1871;
Edwards and Duntley 1939; Frost 1988, 2005; Jablonski and Chaplin 2000). This sex
difference is found in ethnic groups on all continents. That women have lighter skin
than men is well known to people living in ethnically homogenous settings, for whom this
sex difference is the major source of pigmentation variation. For the most readers
this will be a surprise, as the greatest source of pigmentation variation in the modern
world is between racial groups. The studies that have established this sex difference
have measured body parts not exposed to the sun, to control for the possibility of sex
differences in sun exposure and tanning. Because of this, the pigmentation of the face
has not been measured in detail, and it is not known whether females are lighter across
the entire face, including features such as the eyes and lips.
A sex difference in facial contrast and its exaggeration
by cosmetics
Perception, 20 09, volume 38, pages 1211 ^ 1219
Richard Russellô
Department of Psychology, Harvard University, 33 Kirkland Street, Cambridge, MA 02138, USA;
e-mail: rrussell@gettysburg.edu
Received 15 November 2008, in revised form 6 February 2009; published online 6 August 2009
Abstract. This study demonstrates the existence of a sex difference in facial contrast. By measuring
carefully controlled photographic images, female faces were shown to have greater luminance
contrast between the eyes, lips, and the surrounding skin than did male faces. This sex difference
in facial contrast was found to influence the perception of facial gender. An androgynous face
can be made to appear female by increasing the facial contrast, or to appear male by decreasing
the facial contrast. Application of cosmetics was found to consistently increase facial contrast.
Female faces wearing cosmetics had greater facial contrast than the same faces not wearing
cosmetics. Female facial beauty is known to be closely linked to sex differences, with femininity
considered attractive. These results suggest that cosmetics may function in part by exaggerating
a sexually dimorphic attribute
ö
facial contrast
ö
to make the face appear more feminine and hence
attractive.
doi:10.1068/p6331
ô Contact address (as of 17 August 2009): Department of Psychology, Gettysburg College, Gettysburg,
PA 17325, USA; e-mail: rrussell@gettysburg.edu
In faces of both sexes, the eyes and lips are darker than the surrounding skin,
forming an inverted triangle of dark regions surrounded by lighter regions that is
characteristic of faces (Sinha 2002; Watt 1994). Curiously, increasing or decreasing the
magnitude of this facial contrast has opposite effects on the attractiveness of male
and female faces (Russell 2003). In that study, female faces were rated more attractive
when the eyes and lips were darkened than when they were lightened, while male faces
were rated more attractive with those features lightened than with them darkened.
This is interesting considering the relation between sexual dimorphism and attractiveness.
It has been shown by a variety of methods that sex differences in facial appearance
influence attractiveness judgments. The relation is particularly strong in female faces,
with more feminine females considered more attractive (eg Bruce et al 1994; Cunningham
1986; Jones and Hill 1993; O'Toole et al 1998; Perrett et al 1998; reviewed by Rhodes 2006).
This background motivated the hypothesis that there is a sex difference in facial
contrast, with female faces having greater contrast than male faces. Further, if this sex
difference exists, people may consider faces with greater contrast as more feminine,
even though they are not aware of the sex difference. Experiment 1 was designed
to determine whether facial contrast is sexually dimorphic, and experiment 2 was
designed to see whether facial contrast plays a role in the perception of facial gender.
Because typical application of cosmetics involves darkening the eyes and lips, experi-
ment 3 was designed to determine whether female faces have greater facial contrast
with cosmetics than without.
2 Experiment 1
2.1 Method
To test the hypothesis that there is a sex difference in facial contrast (the luminance
difference between the eyes, lips, and the surrounding facial skin), photographs were
taken of 118 clean-shaven and cosmetics-free MIT students. This included 51 East Asians
(25 female, aged 18^ 22 years, mean age 19.4 years; 26 male, aged 16 ^ 23 years, mean
age 19.8 years) and 67 Caucasians (31 female, aged 18 ^ 27 years, mean age 20.5 years;
36 male, aged 17^ 28 years, mean age 20.7 years). To avoid systematic differences in
illumination, all photographs were taken under standard lighting conditions that have
been described in two other studies that used a subset of the images collected for the
present study (Russell et al 2006, 2007). The heights of the camera and lamps were
fixed, and the chair used by the photographic subjects was adjusted such that their
heads were all at the same height. The faces were illuminated by two studio lamps
with large diffusing heads, in a small room with white walls (for greater ambient
illumination). These two lamps, the camera and tripod, and the chair on which the
photographic subjects sat, were kept in locations that were fixed with respect to each
other and the room. The lights were centered at 08elevation (level with the head),
to eliminate cast shadows and to minimize variation from shading (Liu et al 1999).
As demonstrated in figure 1, gray-scale versions of each image were individually
hand-labeled to define regions corresponding to the eyes (including the skin between
the epicanthal fold and the eye, and the skin immediately below the eye), the lips,
annuli surrounding the eyes (with the approximate width of the eyes but not including
the eyebrow), and an annulus surrounding the lips (with the approximation width
of the mouth). Luminance values of all pixels within the eyes were averaged, as were
all the pixels in the lips, the annuli surrounding the eyes, and the annulus surround-
ing the lips, yielding mean luminance values for each of the four regions (eyes, eye annuli,
lips, lip annulus). The mean luminance values for the eyes and lips were averaged to
produce the mean feature luminance. Similarly, the mean luminance values for the eye
annuli and lip annulus were averaged to produce the mean skin luminance. Skin and
feature luminance, both being the averages of 8-bit pixel values, could range from 0
1212 R Russell
(black) to 255 (white). Facial contrast was calculated as C
F
(feature luminance ÿskin
luminance)=(feature luminance skin luminance).This is an adapted version of Michelson
contrast, which varies from 0 to 1, with higher values indicating greater contrast, and 0
indicating no contrast.
2.2 Results
Female faces had greater facial contrast than male faces in both the East Asian
(mean facial contrast: females 0.160; males 0:150) and the Caucasian (mean facial
contrast: females 0.123; males 0.113) samples, and the East Asian faces (with dark
eyes) had greater facial contrast than the Caucasian faces (with lighter eyes). A 2 (sex)
62 (race) analysis of variance (
ANOVA
) of facial contrast found significant main
effects of sex (F
1 114
9:69,p0:002,Z
2
p
0:08) and race (F
1 114
134:25,p50:001,
Z
2
p
0:54). The interaction between sex and race was not significant (F
1 114
0:00,
p0:997,Z
2
p
0:00), indicating that the sex difference in facial contrast did not differ
between East Asian and Caucasian faces. Supporting this notion, the effect sizes for
the sex difference in facial contrast were very similar for East Asian (d0:55) and
Caucasian (d0:60 ) faces.
Figure 2 shows skin luminance plotted against eye and lip (feature) luminance for
each face. The sex difference in contrast can be appreciated by noting that the regres-
sion line for female faces lies further from the line of equal luminance (along which
the skin and features are equally dark) than does the regression line for male faces.
, ,
,
190
150
110
Skin luminance
Asian females
Asian males
Caucasian females
Caucasian males
r0:88
r0:89
equal luminance
80 120 160
Feature luminance
Figure 2. Skin luminance plotted against
feature luminance. Larger values indi-
cate brighter regions. The regression
line for female faces lies further from
the line of equal luminance (faces with
features that are no darker or lighter
than the skin would lie along this line)
than does the regression line for male
faces, indicating that female faces have
greater facial contrast than male faces.
This sex difference does not differ bet-
ween East Asian and Caucasian faces.
Figure 1. Illustration of feature labelling. Solid lines
demonstrate how the boundaries of the eyes and lips were
defined. Dashed lines indicate how the boundaries of the
annuli surrounding those features were defined.
Sex difference in facial contrast 1213
Consistent with previous reports, female skin was lighter than male skin [mean skin
luminance: females 157 (SEM 1:5); males 147 (SEM 1:3)]. Though female eyes
and lips were lighter than male eyes and lips [mean feature luminance: females 119
(SEM 1:6); males 114 (SEM 1:4)], the difference was much smaller than the
difference between male skin and female skin. Thus, the sex difference in facial
contrast is a result of the sex difference in feature luminance being much smaller than
the sex difference in skin luminance.
To rule out the possibility that the sex difference in contrast is simply a function
of the sex difference in skin luminance, a 2 (sex)62 (race) analysis of covariance
(
ANCOVA
) was carried out with facial contrast as the dependent variable and skin
luminance as a control variable. Including skin luminance as a control variable did
not affect the pattern of results, with significant main effects of sex (F
1113
10:75,
p0:001,Z
2
p
0:09) and race (F
1 113
106:49,p50:001,Z
2
p
0:49), but no significant
interaction between sex and race (F
1 113
0:03,p0:854,Z
2
p
0:00). This indicates
that the sex difference in facial contrast exists even when overall skin lightness is controlled.
We can also consider the contrast around the eyes or mouth alone, with eye
contrast calculated as C
E
(eye luminance ÿeye skin luminance)=(eye luminance
eye skin luminance) and mouth contrast calculated as C
M
(mouth luminance ÿ
mouth skin luminance)=(mouth luminance mouth skin luminance). A 2 (sex)62(race)
ANOVA
of eye contrast showed significant main effects of sex (F
1114
6:71,
p0:011,Z
2
p
0:06) and race (F
1 114
155:51,p50:001,Z
2
p
0:58). Female faces
had greater eye contrast than male faces in both the East Asian (mean eye contrast:
females 0.206; males 0.189) and the Caucasian (mean eye contrast: females 0.139;
males 0.131) samples. The East Asian faces (with consistently dark eyes) had much
greater eye contrast than the Caucasian faces (with lighter eyes). The interaction between
sex and race was not significant (F
1114
0:84,p0:362,Z
2
p
0:01). A 2 (sex)62(race)
ANOVA
of mouth contrast showed a significant main effect of race (F
1 114
10:29,
p0:002,Z
2
p
0:08) and a trend toward a main effect of sex (F
1114
3:29,p0:072,
Z
2
p
0:03). Female faces had greater mouth contrast than male faces in the Caucasian
sample (mean mouth contrast: females 0.109; males 0.098) but there was virtually
no sex difference in the East Asian sample (mean mouth contrast: females 0.115;
males 0.114). However, the interaction between sex and race was not significant
(F
1 114
1:58,p0:211,Z
2
p
0:01). Of the two features, the sex difference in contrast
was larger for the eyes than the mouth, particularly for East Asian faces.
It is relevant that there is a sex difference not only in overall luminance of the
face, but also in luminance contrast, because contrast is a robust signal for visual
perception, and the property to which most neurons in the early visual stream respond.
Though luminance contrast is a robust visual cue, the effect size of the sex difference
in facial contrast (d0:55 for East Asians and d0:60 for Caucasians) is much
smaller than effect sizes for well-known sexual dimorphisms such as height (d1:4;
Ogden et al 2004) and waist-to-hip ratio (d1:7; Dobbelsteyn et al 2001). The smaller
effect size is likely the reason why people are not aware of the sex difference in facial
contrast, while they are aware of the sex differences in height and waist-to-hip ratio.
Though people are not conscious of the sex difference in facial contrast, they may
nevertheless use it as a cue in determining the sex of a face or making judgments of
facial masculinity or femininity.
3 Experiment 2
A demonstration of the utility of facial contrast for determining the sex of a face can
be seen in figure 3. Both images were created by manipulating the same original image
of a perceptually androgynous face made by morphing together male and female average
faces (see figure A1 in the appendix). To make both images (with Adobe Photoshop),
,
,
,
,
,
,
,
,
,
1214 R Russell
the eyes and lips were left unchanged, but the rest of the image was darkened to
produce the left image or lightened to produce the right image. Because the eyes and
lips were unchanged while the rest of the face was made darker or lighter, facial
contrast was decreased or increased. Though a subtle manipulation, it has a powerful
effect
ö
making the image on the left with decreased contrast appear male and the image
on the right with increased contrast appear female.
In the Illusion of Sex shown in figure 3, the face with lower contrast also has darker
skin. Because males have darker skin, it is possible that the difference in skin darkness
drives the illusion rather than the difference in facial contrast. To test this possibility,
we can create a pair of faces in which facial contrast is manipulated by darkening or
lightening the eyes and lips but keeping the rest of the face unchanged. These faces
appear in figure 4. Again, the face on the left with decreased contrast appears male
and the face on the right with increased contrast appears female. Because the two faces
have the same skin tone, this provides evidence that facial contrast alone can be used as
a cue for determining the sex of a face. Indeed, facial contrast may in fact be more
important than overall lightness
ö
darkening or lightening the entire face has no effect
on perceived gender (see figure A2 in the appendix). Collectively, these versions of the
Figure 3. The Illusion of Sex. The face on the left appears male, while the face on the right
appears female. Both images were produced by making slight alterations to the same original
image. The eyes and lips were unaltered, and hence equally dark in both images. The remainder
of the image was darkened to produce the left image, and lightened to produce the right image.
The eyes and lips may appear darker in the right image than in the left image, but are not
ö
it
is an example of simultaneous contrast.
Figure 4.Variant of the Illusion of Sex. The face on the left appears male, while the face on the right
appears female. Both images were produced by making slight alterations to the same original
image. The eyes and lips were lightened to produce the left image, and darkened to produce
the right image. The rest of the face was unaltered, and hence equally dark in both images.
That decreasing or increasing facial contrast is sufficient to make a face appear male or female
indicates that facial contrast plays a role in the perception of facial gender.
Sex difference in facial contrast 1215
Illusion of Sex indicate that, while people are not consciously aware of the sex difference
in facial contrast, they nevertheless use it as a cue in perceiving the sex of a face.
Though facial contrast is known to have different effects on male and female
attractiveness (Russell 2003), its relation to perceived masculinity and femininity has
not been explained. Because facial contrast is used as a cue for perceiving the sex of a
face, it would not be surprising if it were also used as a cue for making judgments
of masculinity and femininity. To test the hypothesis that facial contrast is related
to judgments of masculinity and femininity, twenty-nine subjects (fifteen female) gave
Likert-scale ratings of masculinity (for male faces) or femininity (for female faces) to
full-color (RGB) versions of 117 of the 118 images described above. The image excluded
from the set was an Asian female personally known by several subjects. Cronbach's a
indicated high reliability of the judgments of masculinity (a0:88) and femininity
(a0:95). Facial contrast was positively correlated with rated femininity of female
faces (r0:31,p0:022), but negatively correlated with rated masculinity of male faces
(rÿ0:46,p50:001).
These correlations between rated femininity and masculinity and facial contrast
could be a byproduct of skin luminance (which is also sexually dimorphic). With skin
luminance as a control variable, facial contrast was still positively correlated with
rated femininity of female faces (r0:36,p0:008) and negatively correlated
with rated masculinity of male faces (rÿ0:39,p0:002). Even with skin luminance
controlled, greater facial contrast was rated more feminine in female faces but less
masculine in male faces. Another possible confound could come from analyzing the
Caucasian and Asian faces together. To take both skin luminance and ethnicity into
account, the results were analyzed as a partial correlation with skin luminance and
ethnicity as control variables. With skin luminance and ethnicity controlled, facial
contrast was correlated positively with rated femininity of female faces (r0:24,
p0:078), but negatively with rated masculinity of male faces (rÿ0:05,p0:700).
Controlling for ethnicity and skin luminance yields the same pattern of results
(a positive correlation between contrast and femininity but a negative correlation
between contrast and masculinity), but the correlations were weaker and not statisti-
cally significant (particularly for male faces). To summarize, in a set of real faces, a
significant relationship was found between facial contrast and rated masculinity and
femininity, but it was modulated by ethnicity. Overall, the ratings were weakly consistent
with greater facial contrast being considered more feminine and less masculine.
4 Experiment 3
Typical cosmetics usage, by darkening the eyes and lips while little changing the lumi-
nance of the rest of the face, should increase facial contrast. To confirm that this
is the case, 12 Caucasian females (18 ^21 years, mean 19.6 years) were photographed.
These individuals were photographed twice, once with and once without cosmetics.
For the photographs with cosmetics, the women were instructed to ``apply cosmetics as
you would when going out at night'', and applied the cosmetics themselves at home.
Facial contrast was measured with gray-scale images of the faces by the same
methods as in experiment 1. Mean facial contrast was 0.16 (SD 0:04) in the faces
wearing cosmetics, and 0.12 (SD 0:01) in the faces without cosmetics, a significant
difference as assessed by a paired-samples, two-tailed t-test (t
12
5:6,p50:001,
d1:70). The increase of facial contrast was also consistent
ö
all 12 faces had greater
contrast with cosmetics than without. This large increase in facial contrast achieved with
cosmetics more clearly differentiates male and female faces. The effect size of the sex
difference in facial contrast comparing the 36 male Caucasian faces and the 12 female
Caucasian faces wearing cosmetics (d1:85) compares favorably to the effect sizes of
the sex differences in height or waist-to-hip ratio. Application of cosmetics increased both
1216 R Russell
eye contrast [with cosmetics, mean eye contrast 0.17 (SD 0:03); without cosmetics,
mean eye contrast 0:13 (SD 0:03); paired-samples, two-tailed t
12
3:2,p0:009,
d1:15] and mouth contrast [with cosmetics, mean mouth contrast 0.16 (SD 0:04);
without cosmetics, mean mouth contrast 0.10 (SD 0:02); paired-samples, two-tailed
t
12
5:1,p50:001,d1:70]. These results confirm that cosmetics are used in a way
that accentuates a sexually dimorphic feature (facial contrast).
5 Discussion
Investigation of a large set of faces showed that females have greater facial contrast
than do males. This sex difference in facial contrast was found in both East Asian and
Caucasian faces. Female or male faces with greater facial contrast were rated as more
feminine or less masculine than faces with less contrast, though the relation was very
weak for male faces. Decreasing or increasing the facial contrast in an androgynous
face (figures 3 and 4) is sufficient to make it appear male or female. These findings
indicate that, while people are not consciously aware of this sex difference, their per-
ceptual systems nevertheless make use of it. Because femininity and attractiveness are
strongly related (Bruce et al 1994; Cunningham 1986; Jones and Hill 1993; O'Toole
et al 1998; Perrett et al 1998; Rhodes 2006), these results help explain the previous
finding that female faces are more attractive with increased facial contrast than with
decreased facial contrast (Russell 2003).
In the current study, typical application of cosmetics was found to increase the
contrast between the eyes, lips, and the rest of the face
ö
precisely the manipulation
capable of making the face appear more feminine. It is extremely unlikely that this
would happen by chance. Parts of the face could be lightened or darkened in many
different spatial patterns, but only this particular pattern is related to how male and
female faces differ. Further, there is a direction to the spatial pattern
ö
increasing the
contrast makes the face appear more feminine, but decreasing it makes the face
appear more masculine. Yet cosmetics consistently increase facial contrast. Faces are
rated more feminine (Cox and Glick 1986) and more attractive (Cash et al 1989;
Cox and Glick 1986; Graham and Jouhar 1981; Huguet et al 2004; Mulhern et al
2003) when wearing cosmetics than when not wearing cosmetics, whether the cosmetics
are self-applied [as in the Cash et al (1989) study] or professionally applied (as in
the other studies). Together with the current findings, this suggests that an important
function of cosmetics may be to increase the apparent femininity, and hence attractive-
ness, of the female face by increasing facial contrast.
Accentuating sex differences to make the female face appear more feminine and
thereby more attractive is not limited to changing facial contrast. Another common
manipulation of a sexually dimorphic facial feature is eyebrow plucking. Brow thick-
ness and brow-to-eye distance are both sexually dimorphic (Burton et al 1993; Farkas
and Munro 1987), with females having thinner brows that are higher above the eye.
Standard advice (Aucoin 1997; Brown and Iverson 1997) instructs women to pluck the
eyebrows from the bottom side, resulting in a thinner brow that is also further from
the eye, making the face appear more feminine. It is likely that accentuation of sexual
dimorphism as a way to enhance facial attractiveness is a general strategy of cosmetics
and other grooming behaviors.
In addition to sexual dimorphism, there are other biologically based standards
of facial beauty, including averageness (Langlois and Roggman 1990), symmetry
(Thornhill and Gangestad 1993), and youth (Zebrowitz 1997). It is likely that cosmetics
are
ö
or could be
ö
used to manipulate all of these factors. While it is widely believed
that cosmetics are an arbitrary cultural phenomenon largely dictated by fashion, the
present findings suggest an alternative scientific explanation for the use of cosmetics,
premised upon their manipulation of biologically based factors of facial beauty.
Sex difference in facial contrast 1217
Acknowledgments. I thank Jill Jin and Charisse Massey for taking the photos, P Matt Bronstad,
Nancy Etcoff, and Ken Nakayama for comments, and Pawan Sinha for comments and support.
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Appendix
Figure A1. This androgynous face was produced by morphing together Caucasian male and female
averaged faces. It was manipulated to produce the faces in figures 3, 4, and A2.
Figure A2. No illusion. Both the right and left images appear androgynous. The entire original
image (figure A1) was lightened to produce the left image, and darkened to produce the right image.
ß 20 09 a Pion publication
Sex difference in facial contrast 1219
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... Children's books are a significant source of social information, signaling to children who is important enough to be in the books and what those people can do [56]. Many children's books not only reflect an underrepresentation of women and girls, as described above, but also contain gender stereotyping [22,24,46,51,57]. The people who read picture books with children are themselves a significant source of social information that children may use to inform their gender schemas [7]. ...
... Merriam-Webster Dictionary [37] added the singular sense of they to the relevant dictionary entry in September of 2019, recognizing it as the pronoun often used by nonbinary people. However, research has shown that adults experience a processing cost when they is paired with a singular antecedent [46]. This is especially true when the referent of the pronoun is a specific individual whose gender seems to be known, even though it may not be known to the participant [19]. ...
... To my knowledge, there is currently no information on when children develop an understanding of, or how they interpret, singular versus plural they. For adults the mismatch between a singular referent and the use of they seems to be resolved rapidly [46], but that may not be the case for children who have less experience with the use of singular they. It seems likely that children would interpret the unknown they as being plural, since it is always combined with a plural verb even when used in the singular sense. ...
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When people are faced with determining the gender of an unknown person or character the tendency is to assume male. This is a problem for the underrepresentation of women in the media and for children developing their understanding of gender. One hundred twenty-two undergraduate students were assigned to one of six image conditions. Images were of characters from children’s books which were selected to test perception of stereotypically gendered and neutral characters. Participants wrote a story about the image they saw which were then coded for use of gendered or neutral pronouns. The images which were explicitly male and female gender showed significantly different response patterns indicating that participants recognized the gender information. The neutral images were not significantly different from the male image, indicating that participants more often assumed that neutral characters were male. Future research needs to address how to present characters so that they may be viewed as other than male without exacerbating underrepresentation or harmful stereotypes.
... Makeup is believed to increase attractiveness through its effects on visual features, such as skin homogeneity [7] and facial contrast [8]. Makeup has been found to increase skin evenness, using both perceptual and physical measures [7], and skin homogeneity has been found to increase attractiveness [9]. ...
... Makeup has been found to increase skin evenness, using both perceptual and physical measures [7], and skin homogeneity has been found to increase attractiveness [9]. Makeup has also been found to increase facial contrast (i.e., the difference in coloration between facial features and the surrounding skin) in female faces, which also makes faces appear more attractive [8]. ...
... Previous studies have found that skin homogeneity increases perceptions of attractiveness in male facial skin [20]. Previous research has also found that lower facial contrast makes faces appear more masculine [8]. Additionally, bone structure in men (e.g., facial width-to-height ratio) affects perceptions of attractiveness [21]. ...
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Makeup is commonly attributed with increasing attractiveness in female faces, but this effect has not been investigated in male faces. We therefore sought to examine whether the positive effect of makeup on attractiveness can be extended to male faces. Twenty men were photographed facing forward, under constant camera and lighting conditions, with neutral expressions, and closed mouths. Each man was photographed twice: once without any cosmetics applied and another time with subtle cosmetics applied by a professional makeup artist. Two hundred participants then rated those 40 images on attractiveness. The male faces were rated as higher in attractiveness when presented wearing makeup, compared to when presented not wearing makeup. This was true for both male and female raters, and whether analyzing the data using a by-participant or a by-face analysis. These results provide the first empirical evidence that makeup increases attractiveness in male faces. Following work on female faces, future research should examine the effect of makeup on several other traits in male faces. The market for male cosmetics products is growing and evolving and this study serves as an initial step in understanding the effect of makeup on the perceptions of male faces.
... for cleaning, beautifying, promoting attractiveness, or altering the appearance" [2]. Today, several types of makeup products are used, sometimes to enhance facial contrasts to increase femininity and at other times to camouflage perceived skin deficits [3][4][5]. Facial painting has become increasingly fashionable and common among people, resulting in the growth of multi-billion-dollar cosmetic industries [1]. Many people purchase cosmetic products because they believe that the products modify their appearance [5]. ...
... This finding may reflect the influence of makeup on sexual dimorphism in the human face. Several studies have shown that makeup exaggerates the luminance and color contrasts, which are inherently, on average, higher in women's faces than in men's faces [3,4]. Consistent with this idea, participants classified faces as female faster when presented with makeup than when presented without makeup, suggesting that makeup helped them identify the faces as female. ...
... The discrepancy in the RT results can be explained by the relationship between the effects of makeup on facial appearance and the task demands. Makeup reduces facial distinctiveness by obscuring skin roughness and blotches [8][9]15], and makes faces look more feminine by increasing facial luminance and color contrast [3,4]. In Experiment 1, the participant had to judge whether a face presented on the screen was her own face with or without makeup. ...
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Although it is well established that cosmetic makeup enhances perceived facial attractiveness, few studies have examined whether facial makeup modulates neural responses to face images. This study investigated behavioral and attractiveness-related brain responses to self-applied makeup, focusing on the N170, early posterior negativity, P300, and late positive potential components of event-related brain potentials. A total of 77 Japanese women participated in two experiments (N = 34 and 43 for Experiments 1 and 2, respectively). Experiment 1 assessed the effects of self-applied makeup on attractiveness-related event-related potential amplitudes using facial images during a makeup identification task in which makeup was directly relevant to task demands. Experiment 2 examined the effects of self-applied makeup using images of one’s own face and another female’s face when performing a gender classification task, where the presence of makeup had no explicit connection to facial gender classification. In both experiments, faces with makeup were rated as more attractive and elicited more negative early posterior negativity and more positive late positive potential components, regardless of the participant’s own face or another person’s face. These findings suggest that people are spontaneously motivated to pay visual attention to faces with makeup, which supports the idea that makeup adds reward value to the facial appearance of the human. Moreover, neural evidence empirically confirmed that the benefits of makeup are not just limited to how others see your face but also extend to how you see your own face.
... For the current analysis, we instead used facial contrast: the contrast of the lips, eyebrows and eyes against the skin immediately surrounding these features. 25,39 Facial contrast is determined separately for these three facial features: for the current analysis we used the mean average of those individual contrasts. Note that while others report facial contrast as a Michelson contrast, here we use Weber contrast as is required to determine RVP. ...
... It was conducted using the facial contrasts of models representing Caucasian and South African faces, both being young females. This range, therefore, excluded skin tones identified as type I of the Fitzpatrick Scale, 40 labelled as 'ivory', and excluded variations in facial contrast between individuals such as that of gender (females tend to have higher facial contrast than males 39 ). However, resulting differences in RVP are expected to be small compared with those found when comparing Caucasian (type II) with South African (type VI). ...
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This study concerns road lighting for pedestrians. Many experiments have been conducted to determine how changes in lighting affect the ability to make interpersonal evaluations, usually considering variations in light level or light spectrum. Here, we consider an alternative approach, predicting performance using an existing model, Relative Visual Performance. The results show that face evaluation ability is affected by adaptation luminance, pavement surface reflectance, observer age, and skin tone of the observed person. Previous experimental studies have tended to use young test participants to evaluate Caucasian or Asian faces: if the situation instead involved an elderly person evaluating a face of South African skin tone, then the current analysis predicts that for optimal performance the light level would need to be doubled.
... Task with face images. Grayscale face images (9 female and 1 male unique faces) were selected from the MIT Face Database (27,101), cropped to a circle at a visual dimension of 300 × 300, and presented on a gray background. Five-hundred trials (450 female and 50 male face trials) were included in the run, with each unique face image appearing 50 times in a random sequence. ...
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Cognition and attention arise from the adaptive coordination of neural systems in response to external and internal demands. The low-dimensional latent subspace that underlies large-scale neural dynamics and the relationships of these dynamics to cognitive and attentional states, however, are unknown. We conducted functional magnetic resonance imaging as human participants performed attention tasks, watched comedy sitcom episodes and an educational documentary, and rested. Whole-brain dynamics traversed a common set of latent states that spanned canonical gradients of functional brain organization, with global synchrony among functional networks modulating state transitions. Neural state dynamics were synchronized across people during engaging movie watching and aligned to narrative event structures. Neural state dynamics reflected attention fluctuations such that different states indicated engaged attention in task and naturalistic contexts whereas a common state indicated attention lapses in both contexts. Together, these results demonstrate that traversals along large-scale gradients of human brain organization reflect cognitive and attentional dynamics.
... Adult human faces are sexually dimorphic with respect to shape, texture, and colouration. Accordingly, behavioural tests reveal observers' capacity to judge sex on the basis of face properties including overall shape (Bruce et al., 1993;Nestor & Tarr, 2008), contrast (Russell, 2009;Russell et al., 2017), and pigmentation (Bruce & Langton, 1994;Nestor & Tarr, 2008), and from patterns of facial motion (Berry, 1991). Disrupting holistic processing or configural information interferes with sex judgments, suggesting a contribution of whole-face representations (Baudouin & Humphreys, 2006;De Gutis et al., 2012;Zhao & Hayward, 2010). ...
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We efficiently infer others’ traits from their faces, and these inferences powerfully shape our social behaviour. Here, we investigated how sex is represented in facial appearance. Based on previous findings from sex-judgment tasks, we hypothesized that the perceptual encoding of sex is not balanced but rather polarized: for the processes that generate a sex percept, the default output is “male,” and the representation of female faces extends that of the male, engaging activity over unique detectors that are not activated by male faces. We tested this hypothesis with the logic of Treisman’s studies of visual search asymmetries, predicting that observers should more readily detect the presence of female faces amongst male distractors than vice versa. Across three experiments ( N = 32 each), each using different face stimuli, we confirmed this prediction in response time and sensitivity measures. We apply GIST analyses to the face stimuli to exclude that the search asymmetry is explained by differences in image homogeneity. These findings demonstrate a property of the coding that links facial appearance with a significant social trait: the female face is coded as an extension of a male default. We offer a mechanistic description of perceptual detectors to account for our findings and posit that the origins of this polarized coding scheme are an outcome of biased early developmental experience.
Article
Facial cosmetics have powerful effects on person perception, such as increasing perceived attractiveness and competence. One specific aspect of facial appearance affected by makeup is apparent skin evenness. Here, we tested the notion that makeup makes facial skin look more homogeneous in part because of changes made not to the skin, but to the facial features. In two studies, participants made ratings of perceived skin evenness. Ratings were made on two versions of the same faces. In one version, no makeup of any kind was worn, while in the other version, the faces had makeup applied only on the features (digitally in Study 1 and by a professional makeup artist in Study 2). Critically, no makeup was worn on the skin in either condition, such that the physical skin homogeneity was identical. Across both studies, skin was rated as appearing more even in the condition with makeup applied to the facial features. This indicates that cosmetics make facial skin appear more even partly due to products applied only to the facial features. These findings are consistent with recent work demonstrating that skin appearance is affected by contrast with adjacent surfaces, possibly via contrast gain control.
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Este livro foi pensado para ser um primeiro texto introdutório às bases ecológicas e evolutivas do comportamento humano, voltado para o ensino ao nível de graduação. Embora cada capítulo possa ser lido em qualquer ordem, organizamos de modo que a sequência sugerida permita ao aprofundamento paulatino dos diferentes conceitos e disciplinas dedi- cadas aos estudos do comportamento humano.
Article
Sex identification of faces without any cultural or conventional sex cue is primarily based on two independent components: a) shape or facial structure, and b) surface reflectance (skin texture and color). The present work studied the relative contribution of each component by means of two experiments based on 3D face models created with different degrees of masculinity-femininity within a sex continuum. The first experiment utilized totally artificial faces created ex novo by computer. The second employed face models created from photographs of real people. The results of both experiments were consistent. As expected, when both components were present in a face, sex was correctly classified in almost all the cases. More interestingly, the contribution of the “pure” facial structure to the sex perception (with no surface reflectance) was about 80%, whereas 20% of the total information was provided by the surface reflectance. Furthermore, examination of the psychometric curves suggests that the information provided by surface reflectance contributes to a categorical perception of facial sex, since when it is removed the sex is perceived in a more continuous / less categorical way. On the other hand, our stimuli presented a certain “male” bias, repeatedly found in the literature on facial sex perception.
Article
Grooming and dress style have both been found to influence the probability of a job applicant being hired. We argue that as these two elements take effect simultaneously during a job application, it is necessary to simultaneously examine the interaction of these two elements of appearance. Based on cue consistency theory, we propose that grooming and a gender‐inconsistent dress style weaken the effects of each other, especially when the evaluators are men. We used three samples to progressively test our hypotheses. With Sample 1 (n = 142), we found that masculine dress weakened the positive effect of grooming on the hirability of female applicants. Furthermore, the interaction effect of grooming and dress style was stronger for male than for female evaluators. With Sample 2 (n = 152), we found that perceived competence mediated the two‐way interaction effect of grooming and dress style on hirability. We used Sample 3 (n = 155) to further examine whether these findings could be generalized to male applicants and found that the interaction effect of grooming and masculine dress was stronger for male than for female evaluators. Evaluators gave more positive evaluations of candidates who groomed and dressed in a stereotypically consistent manner. When female candidate dressed in a feminine style, grooming increased the likelihood of being hired. Male evaluators preferred an ungroomed female candidate to have a masculine rather than feminine style. For male applicants, masculine dress combined with grooming was a safe choice. Male evaluators preferred congruity to incongruity in appearance, regardless of the gender of the applicant. Evaluators gave more positive evaluations of candidates who groomed and dressed in a stereotypically consistent manner. When female candidate dressed in a feminine style, grooming increased the likelihood of being hired. Male evaluators preferred an ungroomed female candidate to have a masculine rather than feminine style. For male applicants, masculine dress combined with grooming was a safe choice. Male evaluators preferred congruity to incongruity in appearance, regardless of the gender of the applicant.
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It is hypothesized that human faces judged to be attractive by people possess two features-averageness and symmetry-that promoted adaptive mate selection in human evolutionary history by way of production of offspring with parasite resistance. Facial composites made by combining individual faces are judged to be attractive, and more attractive than the majority of individual faces. The composites possess both symmetry and averageness of features. Facial averageness may reflect high individual protein heterozygosity and thus an array of proteins to which parasites must adapt. Heterozygosity may be an important defense of long-lived hosts against parasites when it occurs in portions of the genome that do not code for the essential features of complex adaptations. In this case heterozygosity can create a hostile microenvironment for parasites without disrupting adaptation. Facial bilateral symmetry is hypothesized to affect positive beauty judgments because symmetry is a certification of overall phenotypic quality and developmental health, which may be importantly influenced by parasites. Certain secondary sexual traits are influenced by testosterone, a hormone that reduces immunocompetence. Symmetry and size of the secondary sexual traits of the face (e.g., cheek bones) are expected to correlate positively and advertise immunocompetence honestly and therefore to affect positive beauty judgments. Facial attractiveness is predicted to correlate with attractive, nonfacial secondary sexual traits; other predictions from the view that parasite-driven selection led to the evolution of psychological adaptations of human beauty perception are discussed. The view that human physical attractiveness and judgments about human physical attractiveness evolved in the context of parasite-driven selection leads to the hypothesis that both adults and children have a species-typical adaptation to the problem of identifying and favoring healthy individuals and avoiding parasite-susceptible individuals. It is proposed that this adaptation guides human decisions about nepotism and reciprocity in relation to physical attractiveness.
Article
Thirty-eight American female college students completed several body-image measures and were photographed while wearing their typical facial cosmetics and following the removal of their makeup, in a counterbalanced within-subject experimental design. Results indicated more positive body-image cognitions and affect in the cosmetics-present than the cosmetics-absent condition. The more makeup typically worn by the subject, the greater the body-image differences between the two cosmetics conditions. Sixteen peer judges rated the attractiveness of the women in either the cosmetics-present or the cosmetics-absent photograph. Male judges were less favorable when the women were cosmetics free; female judges were not differentially affected. Findings are discussed in the context of a dynamic state-trait perspective that physical appearance is not simply a fixed, immutable attribute, but rather is altered by individuals to manage and control their self- and social images.
Article
The theory of sexual selection suggests several possible explanations for the development of standards of physical attractiveness in humans. Asymmetry and departures from average proportions may be markers of the breakdown of developmental stability. Supernormal traits may present age- and sex-typical features in exaggerated form. Evidence from social psychology suggests that both average proportions and (in females) "neotenous" facial traits are indeed more attractive. Using facial photographs from three populations (United States, Brazil, Paraguayan Indians), rated by members of the same three populations, plus Russians and Venezuelan Indians, we show that age, average features, and (in females) feminine/neotenous features all play a role in facial attractiveness.
Article
In the current resurgence of interest in the biological basis of animal behavior and social organization, the ideas and questions pursued by Charles Darwin remain fresh and insightful. This is especially true of The Descent of Man and Selection in Relation to Sex, Darwin's second most important work. This edition is a facsimile reprint of the first printing of the first edition (1871), not previously available in paperback. The work is divided into two parts. Part One marshals behavioral and morphological evidence to argue that humans evolved from other animals. Darwin shoes that human mental and emotional capacities, far from making human beings unique, are evidence of an animal origin and evolutionary development. Part Two is an extended discussion of the differences between the sexes of many species and how they arose as a result of selection. Here Darwin lays the foundation for much contemporary research by arguing that many characteristics of animals have evolved not in response to the selective pressures exerted by their physical and biological environment, but rather to confer an advantage in sexual competition. These two themes are drawn together in two final chapters on the role of sexual selection in humans. In their Introduction, Professors Bonner and May discuss the place of The Descent in its own time and relation to current work in biology and other disciplines.
Article
In humans and several other species, face and body symmetry have been found to enhance physical attractiveness. A proposed explanation is that symmetry is a phenotypic indicator of biological fitness. Throughout the world, symmetrical designs also are a common feature in face and body painting and the decorative arts. The implication is that symmetrical designs might provide an additional way to enhance physical attractiveness. To find out, we conducted three experiments, two with human faces and one with abstract or nonrepresentational designs. In Experiments 1 and 2, we showed undergraduate students photographs of pairs of faces and instructed them to choose the more attractive face in each pair. The photographs were of physically symmetrical and asymmetrical faces (as indexed by facial features) that had been decorated with either symmetrical or asymmetrical designs of the kind used in many preindustrial societies. As indexed by the number of times they were chosen, symmetrical faces were judged to be more attractive than asymmetrical faces; adding asymmetrical designs to symmetrical faces decreased their attractiveness; and adding symmetrical designs to asymmetrical faces increased their attractiveness. In Experiment 3, undergraduates made similar choices from pairs of abstract designs taken from several cultures and modified in shape, coloration, and orientation of design features. Symmetrical designs again were judged to be more attractive, with shape and coloration playing the more important roles. We interpret the results as suggesting that the same mechanisms underlying the judgment of physical attractiveness also underlie cultural practices of face painting and abstract art.
Book
Do we read character in faces? What information do faces actually provide? Why do we associate certain facial qualities with particular character traits? What are the social and psychological consequences of reading character in faces? Zebrowitz unmasks the face and provides the first systematic, scientific account of our tendency to judge people by their appearance. Offering an in-depth analysis of two appearance qualities that influence our impressions of others, babyfaceness" and attractiveness", and an account of these impressions, Zebrowitz has written an accessible and valuable book for professionals and general readers alike.The assumption that people's faces provide a window to their inner nature has a long and distinguished history, eloquently expressed in the works of ancient philosophers, like Aristotle, and great writers, like Shakespeare. Zebrowitz examines this assumption, focusing on four central points. She shows that facial appearance, particularly babyfaceness and attractiveness, has a strong impact on how we perceive an individual's character traits and on social outcomes in the workplace, in the criminal justice system, and in other settings. She proposes that facial stereotypes derive from evolutionarily adaptive reactions to useful information that faces can provide. She assesses the accuracy of facial stereotypes in light of plausible links between appearance and character. Finally, Zebrowitz suggests ways to counteract the consequences of reading faces.
Article
Scientists and philosophers have searched for centuries for a parsimonious answer to the question of what constitutes beauty. We approached this problem from both an evolutionary and information-processing rationale and predicted that faces representing the average value of the population would be consistently judged as attractive. To evaluate this hypothesis, we digitized samples of male and female faces, mathematically averaged them, and had adults judge the attractiveness of both the individual faces and the computer-generated composite images. Both male (three samples) and female (three samples) composite faces were judged as more attractive than almost all the individual faces comprising the composites. A strong linear trend also revealed that the composite faces became more attractive as more faces were entered. These data showing that attractive faces are only average are consistent with evolutionary pressures that favor characteristics close to the mean of the population and with cognitive processes that favor prototypical category members.
Article
Humans skin is the most visible aspect of the human phenotype. It is distinguished mainly by its naked appearance, greatly enhanced abilities to dissipate body heat through sweating, and the great range of genetically determined skin colors present within a single species. Many aspects of the evolution of human skin and skin color can be reconstructed using comparative anatomy, physiology, and genomics. Enhancement of thermal sweating was a key innovation in human evolution that allowed maintenance of homeostasis (including constant brain temperature) during sustained physical activity in hot environments. Dark skin evolved pari passu with the loss of body hair and was the original state for the genus Homo. Melanin pigmentation is adaptive and has been maintained by natural selection. Because of its evolutionary lability, skin color phenotype is useless as a unique marker of genetic identity. In recent prehistory, humans became adept at protecting themselves from the environment through clothing and shelter, thus reducing the scope for the action of natural selection on human skin.
Article
Investigated, in 2 quasi-experiments, the relation between specific adult female facial features and the attraction, attribution, and altruistic responses of adult males. Precise measurements were obtained of the relative size of 24 facial features in an international sample of photographs of 50 females. 75 undergraduate males provided ratings of the attractiveness of each of the females. Positively correlated with attractiveness ratings were the neonate features of large eyes, small nose, and small chin; the maturity features of prominent cheekbones and narrow cheeks; and the expressive features of high eyebrows, large pupils, and large smile. A 2nd study asked males to rate the personal characteristics of 16 previously measured females. The males were also asked to indicate the females for whom they would be most inclined to perform altruistic behaviors and to select for dating, sexual behavior, and childrearing. The 2nd study replicated the correlations of feature measurements with attractiveness. Facial features also predicted personality attributions, altruistic inclinations, and reproductive interest. Sociobiological interpretations are discussed. (73 ref) (PsycINFO Database Record (c) 2012 APA, all rights reserved)