Facial Contrast Is a Cross-Cultural Cue for Perceiving Age.

Age is a fundamental social dimension and a youthful appearance is of importance for many individuals, perhaps because it is a relevant predictor of aspects of health, facial attractiveness and general well-being. We recently showed that facial contrast-the color and luminance difference between facial features and the surrounding skin-is age-related and a cue to age perception of Caucasian women. Specifically, aspects of facial contrast decrease with age in Caucasian women, and Caucasian female faces with higher contrast look younger (Porcheron et al., 2013). Here we investigated faces of other ethnic groups and raters of other cultures to see whether facial contrast is a cross-cultural youth-related attribute. Using large sets of full face color photographs of Chinese, Latin American and black South African women aged 20-80, we measured the luminance and color contrast between the facial features (the eyes, the lips, and the brows) and the surrounding skin. Most aspects of facial contrast that were previously found to decrease with age in Caucasian women were also found to decrease with age in the other ethnic groups. Though the overall pattern of changes with age was common to all women, there were also some differences between the groups. In a separate study, individual faces of the 4 ethnic groups were perceived younger by French and Chinese participants when the aspects of facial contrast that vary with age in the majority of faces were artificially increased, but older when they were artificially decreased. Altogether these findings indicate that facial contrast is a cross-cultural cue to youthfulness. Because cosmetics were shown to enhance facial contrast, this work provides some support for the notion that a universal function of cosmetics is to make female faces look younger.

Facial contrast is a cue for perceiving health from the face.

How healthy someone appears has important social consequences. Yet the visual cues that determine perceived health remain poorly understood. Here we report evidence that facial contrast-the luminance and color contrast between internal facial features and the surrounding skin-is a cue for the perception of health from the face. Facial contrast was measured from a large sample of Caucasian female faces, and was found to predict ratings of perceived health. Most aspects of facial contrast were positively related to perceived health, meaning that faces with higher facial contrast appeared healthier. In 2 subsequent experiments, we manipulated facial contrast and found that participants perceived faces with increased facial contrast as appearing healthier than faces with decreased facial contrast. These results support the idea that facial contrast is a cue for perceived health. This finding adds to the growing knowledge about perceived health from the face, and helps to ground our understanding of perceived health in terms of lower-level perceptual features such as contrast. (PsycINFO Database Record

Sclera color changes with age and is a cue for perceiving age, health, and beauty.

Redness or yellowness of the sclera (the light part of the eye) are known signs of illness, as is looking older than one's actual age. Here we report that the color of the sclera is related to age in a large sample of adult Caucasian females. Specifically, older faces have sclera that are more dark, red, and yellow than younger faces. A subset of these faces were manipulated to increase or decrease the darkness, redness, or yellowness of the sclera. Faces with decreased sclera darkness, redness, or yellowness were perceived to be younger than faces with increased sclera darkness, redness, or yellowness. Further, these manipulations also caused the faces to be perceived as more or less healthy, and more or less attractive. These findings show that sclera coloration is a cue for the perception of age, health, and attractiveness that is rooted in the physical changes that occur with age.

Aspects of facial contrast decrease with age and are cues for age perception.

Age is a primary social dimension. We behave differently toward people as a function of how old we perceive them to be. Age perception relies on cues that are correlated with age, such as wrinkles. Here we report that aspects of facial contrast-the contrast between facial features and the surrounding skin-decreased with age in a large sample of adult Caucasian females. These same aspects of facial contrast were also significantly correlated with the perceived age of the faces. Individual faces were perceived as younger when these aspects of facial contrast were artificially increased, but older when these aspects of facial contrast were artificially decreased. These findings show that facial contrast plays a role in age perception, and that faces with greater facial contrast look younger. Because facial contrast is increased by typical cosmetics use, we infer that cosmetics function in part by making the face appear younger.

Influence of skin colour on the detection of cutaneous erythema and tanning phenomena using reflectance spectrophotometry.

BACKGROUND/PURPOSE: This research aims at assessing the influence of baseline skin colour on the ability of reflectance spectrophotometry to detect cutaneous erythema induced by a low concentration of methyl nicotinate (2.5 mM) (first objective), and to detect tanning induced by ultraviolet rays (UVA+UVB) at infra-erythemal doses (second objective). METHODS: Two independent studies were conducted to reach their respective objectives, on 27 women for the first study and on 12 women for the second study. Skin colour measurements were expressed in two different ways: percentages of reflected light at increasing wavelengths lambda (400 nm or =40 degrees. The assumption is that in the darkest skins, the emitted light is mainly absorbed by the melanin in the epidermis. Otherwise, after UV irradiation, the tanning was detectable only for individuals with fair to dark skin defined by ITA <50 degrees. This can be explained by the fact that UV stimulation of the fairest skin subjects, known to be melano-compromised individuals, can only produce a weak tanning that our study did not succeed in detecting.

Travellers to high UV-index countries: sun-exposure behaviour in 7822 French adults.

BACKGROUND: Travel health information includes warning on sun exposure, particularly for fair-skinned individuals travelling to tropical countries. METHOD: A self-completed questionnaire on sun exposure behaviour was sent to the 12,741 French adults enrolled in the SU.VI.MAX cohort. Among the 7822 participants, 196 (110 women and 86 men) declared at least one visit to a high UV-index country over the past year for more than 1 month, subsequently referred to as long-term travellers. The remaining 7626 participants (non-travellers) accounted for 4862 women and 2764 men. RESULTS: Women travellers declared more frequently skin exposure to the sun over the past year, practised tanning in high UV-index areas more than 2h daily, experienced intensive sun exposure than non-travellers. Moreover, they asserted that basking in the sun is very important. Comparable results were found in men. The use of sun protection products was similar in travellers and non-travellers, but women tended to use sunscreen products more often, more regularly and with a higher sun protection factor (SPF) than men. CONCLUSIONS: Specific health education campaigns and pre-travel advice aiming to reduce sun exposure and to improve protective measures against ultraviolet (UV) radiation should be addressed to travellers to countries with high UV-index.

Relationships between visual and tactile features and biophysical parameters in human facial skin.

BACKGROUND/PURPOSE: Skin properties, such as colour, hydration and texture, can be studied on a qualitative basis by a clinical assessment or on a quantitative basis using techniques that measure biophysical properties of the skin. The aim of this study was to explore the links between facial skin features and a range of skin biophysical parameters using multivariate methods. METHODS: A study was conducted on 256 female volunteers from Ile-de-France with apparent healthy skin, aged between 20 and 50, under controlled environmental conditions (mean+/-standard deviation: room temperature 22.9+/-0.3 degrees C; relative humidity 48.5+/-2.3%). The study included a medical questionnaire and a clinical examination of the skin performed by a dermatologist, and a biophysical evaluation of the skin properties. Seventy visual and tactile skin features were assessed on the forehead and the cheek using ordinal variables illustrated by photographic scales. Twenty-eight biophysical measurements were taken in the same areas using the following equipment: Chromameter, Evaporimeter, Corneometer, Skicon, Sebumeter, Sebutape, skin thermometer, skin pH-meter and Silflo. In order to group the variables illustrating a same unimodal phenomenon, a typology of the skin features and a typology of the biophysical parameters were carried out using a clustering method. Then, the relationships between each group of clinical features and each group of biophysical parameters were studied using a series of partial least squares (PLS) regressions. RESULTS: From eight groups of clinical features and three groups of biophysical parameters that were identified, 12 significant PLS regression models were built. Our findings suggest that differences in chromametric measurements express not only differences in skin colour but also differences in skin surface properties, such as skin vascularity status, thickness, and existence of wrinkles, and also demonstrate that the level of sebum excretion can affect other aspects of the skin surface. CONCLUSION: Some skin features assessed clinically do not appear to be linked to any biophysical parameter. This finding confirms that certain phenomena evaluated on the basis of visual or tactile skin features are not assessed on the basis of the biophysical properties of the skin measured by our bioengineering techniques. Indeed, visual skin features mainly appreciate the skin surface aspect, contrary to some biophysical surrogate markers known to provide information on underlying epidermal structures. Therefore, both clinical and biophysical assessments must be associated to supply a relevant and accurate approach for skin aspect characterisation.

Expatriates in high-UV index and tropical countries: sun exposure and protection behavior in 9,416 French adults.

BACKGROUND: Overexposure to sunlight during long stays in tropical countries can reveal short- and long-term harmful effects on the skin of Caucasian residents, especially for fair-skinned subjects. The aim of this study was to describe sun exposure and sun protection behaviors during lifetime among French adults who declared having experienced at least one expatriation period in tropical or high-sun index areas for a duration of more than three consecutive months. METHODS: A self-reported questionnaire on sun exposure behavior was addressed two times, in 1997 and 2001, to the 12,741 French adult volunteers enrolled in the SU.VI.MAX cohort. A total of 8,084 subjects answered to the first survey and 1,332 additional responders answered to the second. Among the 9,416 individuals, 1,594 (652 women and 942 men) corresponded to expatriates and the remaining 7,822 to nonexpatriates (4,972 women and 2,850 men). A descriptive analysis of sun exposure and sun protection behaviors during lifetime of expatriates and nonexpatriates was performed by gender. RESULTS: Among women, 39% of expatriates belonged to the 50 to 60 class of age at inclusion, versus 33% in nonexpatriates (72 and 55% in men, respectively). In women, expatriates declared more frequently having during lifetime exposed voluntarily their skin to the sun, practiced tanning between 11 a.m. and 4 p.m., less gradually exposed their skin, experienced intensive sun exposure, and exposed their skin during nautical sports and practiced naturism. In men, expatriates declared more frequently having experienced intensive sun exposure and exposed their skin during outdoor occupations and during nautical and mountain sports. CONCLUSIONS: Although expatriates are aware of travel health advices concerning the countries where they planned to stay, they are usually poorly informed about sun exposure risk factors. Such individuals who planned to expatriate in countries with a high ultraviolet index should benefit from a visit to a travel clinic including specific health care information for risk related to sun exposure, ie, skin cancers and photoaging.

Effect of hormonal replacement therapy on skin biophysical properties of menopausal women.

BACKGROUND/PURPOSE: Hormonal replacement therapy (HRT) has been shown in the past to influence well being as well as several somatic features in menopausal women. The aim of this analysis was to study the effect of HRT on various biophysical properties of the skin of menopausal women. Two sub-samples were built to test the effect (1) of 'short-term' HRT in recently menopausal women (n=15), and (2) the effect of 'medium- and long-term' HRT in menopausal women (n=78). METHODS: The analysis was performed on data from a study of 106 menopausal Caucasian women with apparent healthy skin. Self-report data on the menopausal status, the duration of the menopause, whether or not HRT has been taken and the duration of the HRT were collected. A series of biophysical measurements on the cheek, the forehead and the inner forearm were performed under controlled environmental conditions. Twenty women were menopausal for less than 5 years (eight with HRT for at least 1 year and seven who had never taken HRT) and 86 women for at least 5 years (35 with HRT for at least 5 years and 43 who had never taken HRT). Analyses of covariance with adjustment for age were performed. RESULTS: With regard to skin colour, the measurements in women treated for at least 1 year were significantly higher for red intensity (a*) and lower for brightness (L*) on the forearm as compared with the non-treated women. Furthermore, yellow intensity (b*) mean values were higher on the forehead and the forearm in women treated for at least 5 years compared with the non-treated women. Concerning sebum casual level, the mean values were significantly higher on the forehead and the cheek in women treated for at least 5 years. Regarding skin surface parameters reflecting hydration, the mean values for capacitance on the forehead and the cheek were significantly higher in women treated for at least 5 years. Finally, as regards with skin relief, parameters mean values for amplitude and roughness on the forehead were significantly higher in women treated for at least 5 years. CONCLUSION: The skin colour parameters showed a higher red intensity value in menopausal women who had been treated for at least 1 year. In menopausal women who had been treated for at least 5 years, the biophysical measurements were significantly higher for the parameters reflecting hydration and sebum secretion, which generally decrease after the menopause. These features were associated with higher values for the yellow intensity parameter and the skin relief parameters on the forehead. Our results support the subjective impression and the clinical evaluation concerning the impact of HRT on the development and the evolution of some skin properties after menopause.

Relative contribution of intrinsic vs extrinsic factors to skin aging as determined by a validated skin age score.

OBJECTIVE: To assess the relative contribution of intrinsic aging vs lifestyle factors to facial skin age. DESIGN: Prospective analysis of a cohort. SETTING: Skin research institute. STUDY SUBJECTS: A cohort of 361 white women (age range, 18-80 years) with apparently healthy skin. MEASUREMENTS: Visual and tactile assessment of facial skin features. RESULTS: Twenty-four skin characteristics were used to build a skin age score (SAS). The relationship between the SAS and chronological age followed a linear model with 2 plateaus--1 before age 30 years and 1 after age 71 years. An analysis was performed to determine whether certain lifestyle habits known to have effects on skin aging were related to the discrepancies between chronological age and the SAS. Significant effects were identified for phototype, body mass index, menopausal status, degree of lifetime sun exposure, and number of years of cigarette smoking. However, these factors accounted for only 10% of the discrepancies. Moreover, most skin characteristics used reflected changes understood to represent intrinsic aging rather than photodamage or other extrinsic factors. CONCLUSIONS: An SAS can be generated from multiple discrete signs evaluated on facial skin and is an informative tool for quantifying skin aging. The SAS is influenced by factors already recognized to affect the aging phenotypes; however, factors related to the rate of intrinsic aging, presumably genetic in character, seem to play a larger role than previously suspected.