Beauty
There is a common saying: “Beauty is in the eye of the beholder.” This means that each person (the beholder) has his or her own opinion about what is beautiful. For example, some people lie in the sun to make their skin darker. Others do not approve of this exposure to the sun and wear sun guard to stop their skin from getting dark. In some societies, people struggle to get enough to eat, so body fat is thought to be an asset. A person from those societies may find a heavier person more attractive than a thinner person. People from other societies may think differently.
However, what we call beauty may also be nature giving priority to health when choosing a mate. Scientists have looked at how people assess female beauty and have found similar things among different societies. In one investigation, researchers looked at the waist-to-hip ratio: the size of the waist in comparison with the size of the hips. They found that the ideal ratio is virtually the same across cultures. The ideal for women of 0.70:1 is not only a sign of beauty; it also predicts good health and easy childbirth. Obviously then, nature and evolution play a part in our idea of beauty.
So when we say someone is truly beautiful, it expresses both our personal opinion and the influence of nature and culture.