This is because body fat buildup around the waist (the apple shape) poses a higher health risk than a fat buildup at the hips (the pear shape). Compared to males, females generally have relatively narrow waists and large buttocks, and this along with wide hips make for a wider hip section and a lower waist–hip ratio. Research shows that a waist–hip ratio (WHR) for a female very strongly correlates to the perception of attractiveness. Women with a 0.7 WHR (waist circumference that is 70% of the hip circumference) are rated more attractive by men in various cultures. Such diverse beauty icons as Marilyn Monroe, Sophia Loren and the Venus de Milo all have ratios around 0.7. In other cultures, preferences vary, ranging from 0.6 in China, to 0.8 or 0.9 in parts of South America and Africa, and divergent preferences based on ethnicity, rather than nationality, have also been noted. Many studies indicate that WHR correlates with female fertility, leading some to speculate that its use as a sexual selection cue by men has an evolutionary basis. However it is also suggested that the evident relationships between WHR-influencing hormones and survival-relevant traits such as competitiveness and stress tolerance may give a preference for higher waist-hip-ratios its own evolutionary benefit. That, in turn, may account for the cross-cultural variation observed in actual average waist-hip-ratios and culturally preferred waist-to-hip ratios for women. WHR has been found to be a more efficient predictor of mortality in older people than waist circumference or body mass index (BMI). Over the past several hundred years, there has been a shift towards viewing the body as part of one's identity – not in a purely physical way, but as a means of deeper self-expression. David Gauntlett, in his 2008 book, recognizes the importance of malleability in physical identity, stating, "the body is the outer expression of our self, to be improved and worked upon". One of the more key factors in creating the desire for a particular body shape – most notably for females – is the media, which has promoted a number of so-called "ideal" body shapes. Fashionable figures are often unattainable for the majority of the population, and their popularity tends to be short-lived due to their arbitrary nature. During the 1950s, the fashion model and celebrity were two separate entities, allowing the body image of the time to be shaped more by television and film rather than high fashion advertisements.