Dimples have a reputation as one of those classic “cute genetic trait” examples, right up there with attached earlobes and widow’s peaks. You’ve probably heard someone say dimples are a simple dominant trait, meaning just one copy of the gene guarantees them. It’s a tidy explanation, and it’s also not quite right.
The real story is a little messier, and honestly a lot more interesting than the one-gene version most people grew up hearing.
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What Causes Dimples
Dimples form because of a small variation in the structure of the zygomaticus major, the facial muscle responsible for pulling the corners of your mouth up when you smile. In most people, this muscle runs as a single, continuous band. In people with dimples, the muscle is shorter or split into two bands, which creates a small tether pulling the skin inward when the muscle contracts. That inward pull is what forms the visible indentation you see when someone smiles.
Not a Simple Dominant Trait
The idea that dimples follow a straightforward dominant inheritance pattern comes from older, simplified genetics education, similar to how eye color used to be taught as a one-gene trait before more nuanced research came along. In reality, dimple formation is influenced by several genes and can vary in expression, meaning someone can carry the genetic tendency for dimples without necessarily developing them, or develop them on only one side despite carrying variants associated with both. This is also why dimples can skip a generation or appear in a child even when neither parent visibly has them.
Dimples can appear on one cheek, both cheeks, or occasionally on the chin, where a similar underlying muscle structure creates the same kind of small tethered indentation.
How Common Are Dimples
Cheek dimples are considered a fairly common facial trait worldwide, though exact prevalence estimates vary by population and study. They’re often noticed more in childhood, since baby fat can make the indentation more pronounced, and may become less visible as facial fat distribution changes with age. Chin dimples are less common than cheek dimples and involve a slightly different underlying structure in the jawbone and muscle rather than the zygomaticus major.
Do Dimples Affect Your Health
Dimples are a purely cosmetic trait with no health implications. They don’t affect how well your facial muscles function, and having them (or not) has no bearing on any physical health measure. They’re essentially a structural quirk of a smile muscle, nothing more.
What Your Dimple Genetics Mean for You
If you’ve ever wondered exactly which genetic variants contributed to your own dimples, or why they showed up on one side and not the other, a detailed DNA report can dig into the specific markers linked to facial structure traits like this one. It’s a fun way to put real science behind a feature people have probably complimented you on for years.
Frequently Asked Questions
Are dimples always inherited from a parent?
Not necessarily in a direct, predictable way. Because multiple genes are involved and expression can vary, a child can have dimples even if neither parent visibly does, or lack them despite both parents having them.
Why do some people have dimples on only one side?
The muscle variation that causes dimples can occur on just one side of the face, which is why asymmetrical dimples, sometimes showing up only when smiling on one side, are common.
Do dimples disappear with age?
They can become less visible as facial fat distribution and skin elasticity change over time, though the underlying muscle structure that causes them typically remains.
Are cheek dimples and chin dimples caused by the same gene?
No. Cheek dimples come from a variation in the zygomaticus major muscle, while chin dimples involve a different structural feature related to the underlying jawbone and muscle, so they aren’t governed by the same genetic mechanism.
Can dimples be surgically created?
Yes, there’s a cosmetic procedure called dimpleplasty that creates an artificial dimple by forming a small tether in the cheek muscle, mimicking the natural structure that produces genetic dimples.
So the next time someone tells you dimples are just a simple dominant gene, feel free to set the record straight. It’s a small trait with a surprisingly layered genetic story behind it.
