Abstract
BACKGROUND: It is unknown whether facial or surrounding (eg, hair and clothing) cues have the strongest influence on the perceived age of subjects in photographic images, and which drives links between perceived age and survival. METHODS: In 2001, 187 Danish twin pairs (n = 374) aged 70+ years were photographed generating passport-type images. The faces of the twins in these images were swapped creating two new images per twin pair (748 images in total). Ten nurses rated the perceived age of the twin from the original and swapped facial images. The survival of the twins was determined through to the end of 2013. RESULTS: Changing the face or its surrounding significantly changed the perceived age of the images, with only a marginal difference between their effect sizes (difference of 0.5 years, 95% confidence interval CI -0.1 to 1.1). Perceived age, adjusting for chronological age, and sex, was a predictor of survival up to 7 years (hazard ratio 1.17, 95% CI 1.10-1.25) and also 7-12 years (hazard ratio 1.06, 95% CI 1.00-1.12) after the photographs were taken. Where the older looking twin died first they had a significantly older looking face (1.4 years older, 95% CI 0.3-2.6) but not surrounding (0.3 years older, 95% CI -0.8 to 1.4) compared to where the older looking twin died second. CONCLUSIONS: Facial visual cues but not hair or clothing cues drive the link between perceived age and survival.