In different cultures of the world, many artists have made their female models lighter skinned than male models. There exists a biologic truth behind these observations. Several spectrophotometric studies have found that female skin reflectance is 2–3 percentage points above (that is, paler skin) that of males in diverse populations in Europe, Asia, Africa, and North and South America. The sex difference in skin pigmentation is, however, subtle and often difficult to appreciate. Probably artists have used pigmentation to emphasize sexual differences between men and women in the same way they use body size and musculature.