Facial skin condition, health and perception in Malaysian Chinese

Physical appearance is an important determinant of mate choice, as attractiveness is thought to reflect the health and fertility of an individual. Previous research on health perception has focused mainly on facial shape, with far fewer studies examining skin condition. Only more recently, psychologists have started to highlight the importance of skin texture and colour in determining the apparent health of faces. Both the surface topography and the colouration of skin contribute to the judgment of apparent health (Fink, Grammer, & Thornhill, 2001; B. Jones, Little, Burt, & Perrett, 2004; Matts, Fink, Grammer, & Burquest, 2007; Samson, Fink, & Matts, 2010; Stephen, Coetzee, Law Smith, & Perrett, 2009; Stephen, Coetzee, & Perrett, 2011), and have been linked to aspects of physiological health, including fitness, immunity and fertility (Armstrong & Welsman, 2001; Jones et al., 2015; Stephen et al., 2011). The current thesis examines the contribution of skin condition to health perception in Malaysian Chinese. The thesis comprises six chapters. Chapter one offers a general introduction to the topic. It outlines key literature on health perception, and explains the research problem, the objectives and relevance of the studies conducted. Chapter 2 consists of three studies which examine Malaysian Chinese participants’ perception of apparent health. The three studies revealed the significance of both skin texture, and skin colour in forming health perceptions. Examining the sensitivity threshold of human vision to colour changes, Chapter 3 discovered that individuals tend to be more sensitive towards changes in redness and yellowness than luminance; and this extra-sensitivity in chrominance is specific to the perception of human faces, and not non-face objects or colour patches. This further strengthens Changizi and colleagues' (2006) hypothesis that trichromatic colour vision may have been selected because of its utility in recognising subtle changes in skin colour associated with health and social cues. Following the finding of preference for slightly yellower skin in Chapter 2, an intervention was conducted to examine the impact of carotenoid rich smoothie on human skin colour, and the outcomes of this study are reported in Chapter 4. An increment in skin yellowness and redness was observed for participants who were prescribed the smoothie (and not for the control group). This chapter also analyses the dietary patterns of Malaysian Chinese, specifically their fruit and vegetable consumption. Using the face images obtained in the intervention study, the three perceptual studies in Chapter 5 were designed to examine the amount of carotenoid colouration that is needed to optimize healthy appearance of Malaysian Chinese faces. Too much colour change was not preferred and, in the last study, it seems that the appropriate amount of carotenoid colouration preferred is only one third of the amount observed in the intervention study. A reduction of carotenoid supplementation is proposed, and whether that will improve one’s perceived health warrants future research. Collectively, these ten studies deepen our knowledge of health perception, especially the importance of skin colour in determining perceived human facial health. Implication and suggestions for future research are presented in Chapter 6