When you observe people closely, you’ll notice that some have visible smile lines or dimples, while others do not.

These small facial details often raise questions: Why do they form? Do they reveal anything about our health or personality? Let’s explore the science and cultural symbolism behind them.

What Are Smile Lines and Dimples?

Smile lines, also called nasolabial folds, are the creases that extend from the sides of the nose down to the corners of the mouth. They tend to stand out more when we smile or laugh, though for some people, they remain noticeable even when the face is at rest.

Dimples, on the other hand, are tiny indentations that appear whenever a person smiles. Unlike wrinkles, dimples are not caused by aging—they result from a unique muscle formation beneath the skin.

Why Do Some People Have Them?

Genetics
Dimples are primarily hereditary. If one or both parents have them, children are more likely to inherit the trait. This happens because of a variation in the zygomaticus major muscle. Instead of forming as one bundle, the muscle splits into two, pulling the skin inward and creating the indentation.

Age and Skin Elasticity
Smile lines develop from both genetic and environmental influences. As we age, collagen and elastin levels in the skin naturally decline, making these folds more visible. External factors such as sun exposure, smoking, and repetitive facial expressions can also deepen them over time.