When you look at identical twins, the resemblance often hits you immediately. At the same time, expert estimates of “how much of the face is genetics” were for years surprisingly low—or varied widely between studies—especially when faces were measured only from 2D photos. That’s why the shift brought by 3D facial scans and automated shape “mapping” is so interesting: they make it much more precise to identify which areas of the face are under strong genetic control and where environment and lifestyle have a bigger say.
What “heritability” means—and why people often get it wrong
Heritability (in the statistical sense) doesn’t mean that a specific person has a “70% genetic nose” and the rest is down to environment. It’s an estimate for a population at a particular time and in a particular setting: how much of the variation between people can be explained by genetic differences. If, for example, the environment is very similar (diet, healthcare, living conditions), genetics can look stronger in the statistics because the environment isn’t adding much variability. Conversely, when lifestyle differences are large, heritability can drop even though genes still matter.
Why older studies often came out “oddly” low
The face is three-dimensional, and its shape is full of subtle curves, transitions, and details that can easily be distorted in an ordinary photograph by camera angle, lighting, or facial expression. For many years, research relied on manually marking a handful of landmarks on the face (eye corners, nose tip, mouth corners) and measuring mostly the distances between them. This kind of measurement is prone to error and also reduces the face to a few lines, which can lead to unstable results across studies. That’s why it often happened that the same trait (for example, nose width) had a markedly different heritability in one paper than in another.
A large 3D twin study: what changed in practice
In an open-access study published in Scientific Reports, researchers used 3D facial scans and a large twin dataset from TwinsUK. Specifically, they worked with 952 twins and, instead of a few manual landmarks, used an automated procedure that placed thousands of points across the face so it could be compared “point by point” between individuals.
Which areas of the face look the most “genetic”
With detailed 3D mapping, some facial regions turned out to have heritability often around 0.7 or even higher—meaning genetics explains a large share of the differences between people. The most pronounced include the chin area, several parts of the nose, the nasolabial folds, the upper lip, and the cheekbones (zygoma). Interestingly, for traditional distance measures (such as cheekbone width or nose width), the values in this study were often higher than in older photo-based studies, suggesting the 3D approach captures true shape more accurately.
How “heritability maps” are made—and why they’re interesting beyond science
The key isn’t just sample size, but also how the face is described mathematically. Here, the researchers worked with curves and surface curvature (different types of curvature metrics), so they weren’t only assessing where the tip of the nose is, but also how the surface bends in a given area and what shape it has. The result is maps you can inspect visually and compare across different facial regions in 3D, which is intuitive even for non-specialists.
Why even identical twins aren’t exactly the same
Even though identical twins share virtually the same DNA, there are still many things that can contribute to differences. Weight changes, teeth and jaw (for example, orthodontic treatment), scars, sun exposure, smoking, sleep, or long-term facial-expression habits can all affect appearance—especially the soft tissues. On top of that, skin elasticity and subcutaneous tissue change over time, so an identical genetic “baseline” can look different with age. That’s why it’s fair to treat heritability as a probability map across a population, not a verdict on a particular person.
What an everyday reader can take away
If you’ve ever wondered why you “got your mom’s nose” or “your dad’s chin,” modern 3D studies offer a better answer than old measurements from photos. Some traits really do come out as strongly heritable, but there are also areas and layers of appearance that are much more sensitive to lifestyle, health, or age. The practical takeaway is simple: genes set the structural “boundaries,” but how a face looks in real life is also shaped by factors we can at least partly influence.
Video: Can a face be predicted from DNA?
The following video explains well where research on faces and genetics is headed—and why the topic is sensitive from a privacy perspective too. It’s a good add-on if you want to understand the broader context, not just the numbers from a single study.
Sources
- Heritability maps of human face morphology through large-scale automated three-dimensional phenotyping (Scientific Reports, 2017) — https://www.nature.com/articles/srep45885
- Heritability maps of human face morphology through large-scale automated three-dimensional phenotyping (PubMed record) — https://pubmed.ncbi.nlm.nih.gov/28422179/
- 3D Face Heritability Viewer (interactive map viewer) — https://www.heritabilitymaps.info/
- Source text provided in the assignment (pasted.txt) —
Jana
I like turning curiosity into words, and writing articles is my way of capturing ideas before they slip away — and sharing them with anyone who feels like reading.
