Hair genetics is more complex than most people realize. At Kopelman Hair, we regularly meet patients wondering whether their traits come more from their mother’s side or their father’s. Dr. Kopelman and his team use over 40 years of experience to explain how inherited factors interact with lifestyle to influence your long-term scalp health.
Key Takeaways
- Both parents contribute to your hair genetics. Men get the AR gene from the mother’s X chromosome, women get an AR copy from each parent, and many other genes come from either side.
- Traits like balding, color, and graying are polygenic, meaning multiple genes are involved rather than a single inherited factor.
- Most of the relevant genes are autosomal, meaning they are passed down from either parent independently of the X chromosome.
- Family history is a better guide than any one relative, so look at your father, both grandfathers, and your brothers.
- Lifestyle choices like nutrition, stress, and smoking can accelerate a genetic predisposition to thinning.
- Medical treatments and restoration surgery with specialists like Dr. Kopelman can help manage hereditary shedding.
Which Parent Do You Get Your Hair From?
Both. The idea that baldness comes only from your mother’s side is a persistent myth. Your mother’s X chromosome carries the AR gene, which affects how follicles respond to androgens, but your father’s genes shape thickness, coverage, and density. So who do you inherit your hair from? A blend of both sides of the family.
Male pattern baldness has an estimated heritability of about 80%, meaning roughly 80% of the variation between men is attributable to genetic differences (Pirastu et al., Nature Communications 2017). If your father or paternal grandfather dealt with significant thinning, you carry a meaningful portion of that risk regardless of your maternal side.
Because so many genes are involved, two siblings can inherit entirely different combinations and end up with noticeably different hair, even with the same parents.
Where Do Children Get Their Hair Genes From?
Equally from both parents at the chromosome level. Each parent passes on 23 chromosomes, so a child ends up with 46, and which copy of each gene arrives is a matter of chance. Because most hair traits depend on many genes lining up, a child may resemble one parent, blend both, or look different from either.
The AR Gene and X-Linked Inheritance
The AR gene regulates how follicles respond to dihydrotestosterone (DHT), a hormone derived from testosterone. When follicles are genetically sensitive to DHT, it causes them to miniaturize over time, producing finer hair until growth stops. This is the same pathway that a DHT blocker targets.
Men have only one X chromosome, so they feel AR gene variants more directly, with no second copy to offset a high-sensitivity variant. A 2005 study in the American Journal of Human Genetics identified variation in the AR gene as a major determinant of early-onset male pattern baldness.
A 2017 meta-analysis in Nature Communications identified 63 genetic loci linked to male pattern baldness, six of them on the X chromosome, including the well-established AR locus. Together they explain about 39% of the variance in the trait, and most of them are not on the X chromosome at all.
Autosomal Genes: Why Dad’s Side Matters Too
Of the 63 loci in that study, 57 are autosomal, meaning they sit on chromosomes unrelated to sex determination and can be inherited from either parent. That is why a father’s pattern matters even though he passes his Y chromosome, not his X, to his sons.
If your father started thinning in his thirties, that is relevant to your own risk, even if your maternal grandfather had a full head of hair. Focusing only on your mother’s side gives you an incomplete picture.
Does Hair Loss Come From Your Mother’s Father?
Partly, but not only. The X chromosome a man receives from his mother is a mix of the two X chromosomes she carries, one from each of her parents, so some X-linked risk can trace back to the maternal grandfather. The six X-chromosome loci in the 2017 meta-analysis may help explain why men often resemble their maternal grandfathers (Heilmann-Heimbach et al.).
Because 57 of the 63 loci are autosomal, your father, your paternal grandfather, uncles on both sides, and brothers matter as well. Each grandparent contributes roughly a quarter of your DNA on average, so the broader the pattern of thinning across relatives, the stronger the genetic signal.
Genetic testing for thinning risk
DNA tests can detect AR gene markers and other relevant variants from a saliva sample. Results cannot predict exact timing but help guide preventive care decisions.
So which side of the family do you get your hair from? Both, which is why the whole family tree is a better guide than any single relative. Early temple recession or crown thinning in your twenties or thirties often points to genetics; our guide to the signs of hair thinning explains what to watch for.
Gene Inheritance Breakdown: X-Linked vs. Autosomal
| Gene / Locus | Chromosome Type | Inherited From | Primary Effect |
|---|---|---|---|
| AR Androgen receptor | X chromosome | Sons: mother. Daughters: both parents | DHT sensitivity in follicles; the best-established X-linked risk locus for male pattern baldness |
| 57 autosomal loci Identified in Heilmann-Heimbach et al., 2017 | Autosomes (non-sex chromosomes) | Either parent | Overall baldness risk, with many acting through follicle development and growth pathways |
| MC1R Melanocortin 1 receptor | Autosome (Chr 16) | Both parents (one copy each) | Melanin type; determines color range from red/blonde to dark brown/black |
| IRF4, SLC24A4 Pigmentation-associated genes | Autosomes | Either parent | Pigmentation variation; IRF4 is also the first gene linked to gray hair |
This breakdown shows why the common belief that baldness comes only from mom is incomplete. Most baldness genes are autosomal, and so are the main color and texture genes, so dad’s contribution is just as significant.
Male vs. Female Genetics
Where Do Men Get Their Hair Genes From?
Men get their hair genes from both parents. The single X chromosome, and the AR gene on it, comes from the mother. The father supplies the Y chromosome plus one copy of every autosome, and most of the known baldness loci are autosomal.
In men, the AR effect typically shows as temple recession and crown thinning, often in the twenties or thirties. Our guide to male hair loss covers the stages and treatments.
Where Do Women and Girls Get Their Hair Genes From?
Women get their hair genes from both parents too, but the X-linked picture differs. A woman has two X chromosomes, one from each parent, so she receives an AR gene copy from her mother and another from her father. The same applies to girls, whose inheritance is set at conception even though visible thinning usually appears much later.
Autosomal variants linked to thinning can also come from either side, so a woman whose father had significant thinning is not protected from a similar pattern. In women, genetic thinning typically shows as diffuse loss across the top of the scalp rather than recession at the temples and crown. Visible thinning generally takes more to develop in women because of hormonal differences, but the inherited risk can surface during pregnancy, postpartum recovery, and menopause. Our guide to female hair loss explains the patterns in more detail.
According to the American Hair Loss Association, about 90% of women with androgenetic alopecia have androgen levels within the normal range, so estrogen signaling and other hormonal pathways appear to play an independent role. The same source notes that hormonal birth control can trigger thinning earlier in women with a family history. The genetics are also more variable in women, and some have clear genetic thinning without an obvious family history.
Does Hair Thickness Come from Mom or Dad?
Both parents contribute. Thickness is determined by follicle size and shape, which are influenced by multiple genes. If both parents have dense, coarse hair, you likely will too. If one parent has fine hair and the other thicker growth, you will probably fall somewhere between the two.
Genetic factors play a major role in texture and thickness, though hormones, medications, and age can also change them (MedlinePlus). Ancestry matters too: people of East Asian descent tend to have thicker, rounder hair shafts, those of European descent show more varied textures, and people of African descent tend to have flatter, more elliptical follicles that produce a tighter curl pattern. These tendencies reflect how deeply follicle architecture is encoded in DNA.
Is Curly Hair Dominant or Recessive?
Neither, in the simple sense. Curly hair is not controlled by one dominant or recessive gene; many genes contribute, and they differ by ancestry. MedlinePlus names TCHH as a texture gene in people of northern European ancestry and EDAR as linked to thickness in people of Asian ancestry, and a 2016 study in Latin American groups tied the PRSS53 gene to hair shape (Nature Communications).
In practice, texture works as a spectrum. If one parent has very curly hair and the other very straight hair, a child often ends up wavy or somewhere in between. If both parents are curly, a child is more likely to be curly, though not guaranteed, and two wavy parents can have a child with straighter or curlier hair than either of them.
Genes for Color and Gray Hair
Hair color depends on the type of melanin follicles produce. The MC1R gene, one of the most studied genes in pigmentation, helps determine whether cells produce eumelanin (dark shades) or pheomelanin (red and lighter shades). People inherit two copies of MC1R, one from each parent, and the interaction between those copies shapes the result.
Color is still polygenic, with many other genes contributing to the final outcome. You can learn more about the MC1R gene’s role in pigmentation from MedlinePlus.
Gray hair genetics does not come from mom or dad alone. The pace at which pigment cells slow down is heritable, so if your parents grayed early, you are likely to as well. The first gene linked to graying, IRF4, was identified in a 2016 genome-wide study and helps regulate how melanin is made and stored (Nature Communications). A 2022 review in the Journal of Clinical Medicine describes how stress, nutrition, and lifestyle can accelerate the process, but the baseline timeline is largely genetic.
Other Factors Beyond Genetics
Hair growth is largely genetic: the genes identified in large baldness studies cluster in pathways that control follicle development and growth (Pirastu et al.). Genes set the baseline, though, and other factors shape how and when it shows.
DHT miniaturizes follicles over time, but its impact varies with overall androgen levels, age, and health status. Smoking, poor nutrition, chronic stress, and tight hairstyles that create repeated mechanical tension can all worsen a genetic predisposition, sometimes bringing on visible thinning earlier than the genes alone would suggest.
Myths About Genetics and Thinning
“Baldness only comes from your mom’s side.” Not true. Both X-linked and autosomal variants contribute, and 57 of the 63 loci in the major 2017 meta-analysis are autosomal.
“There’s a single baldness gene.” Baldness is polygenic. Dozens of variants interact with hormones and the environment, which is why outcomes differ even among siblings. MedlinePlus notes that the inheritance pattern of androgenetic alopecia is unclear because many genetic and environmental factors are likely involved.
“Inherited traits follow simple rules.” They do not. Unlike Mendelian traits, where one gene drives one outcome, thinning follows polygenic inheritance, where many small-effect genes combine to determine what you see.
“Baldness skips a generation.” It can look that way, but genetic hair loss is about probability. A parent can carry risk variants without much visible loss, while a child inherits a different combination that crosses the threshold for visible thinning.
Preventive Steps if Thinning Runs in Your Family
Early action is more effective than waiting for visible change. Maintain scalp hygiene, eat a diet with adequate protein and micronutrients, avoid smoking, and manage chronic stress. A healthy scalp environment gives follicles the best chance of completing their natural growth cycles.
Can Genetic Thinning Be Treated?
Medical and surgical treatments
Hereditary thinning can be slowed and, in many cases, partially reversed. Minoxidil prolongs the active growth phase of the follicle cycle.
A randomized controlled trial in the Journal of the American Academy of Dermatology found that 5% topical minoxidil produced significantly greater regrowth than a placebo after 48 weeks.
Finasteride inhibits the enzyme that converts testosterone to DHT. A review of the phase III trials in the journal Drugs reported that 83% of men with crown thinning who took it daily had no further loss in hair count after two years, compared with 28% on placebo.
Laser therapy may improve scalp circulation and support follicle activity in areas of diffuse thinning. Hair transplant surgery performed by Dr. Kopelman redistributes healthy, DHT-resistant follicles from stable donor areas to thinning zones for long-term results.
When to consult a restoration specialist
If thinning is visible, or your family history suggests a strong predisposition, seek professional input before the situation feels urgent. Early intervention gives you more options. At Kopelman Hair, patients receive thorough evaluations and personalized treatment plans built around their genetic profile, pattern, and goals. To explore your options and receive a personalized solution, schedule a consultation with Dr. Kopelman today.
Hair Genes FAQs
Is hair genetics from mom or dad?
Both. In men, the AR gene comes from the mother’s X chromosome, but most genes linked to thinning, thickness, and texture are autosomal and can be inherited from either parent.
Where do hair genes come from?
They come from both sides of the family. A 2017 study in Nature Communications identified 63 genetic loci associated with male pattern baldness, and 57 of those are autosomal, passed on by mothers and fathers alike.
Who do you get your hair genes from if you are female?
From both parents. A woman receives one X chromosome, and an AR gene copy, from each parent, and autosomal variants linked to thinning can come from either side. Female pattern thinning typically presents as diffuse loss rather than recession, but the inherited component works the same way.
Is baldness only inherited from your mother's side?
No. Male pattern baldness is about 80% heritable, and 57 of the 63 genetic loci linked to it are autosomal, so both sides of the family contribute.
Can your father's genes cause thinning?
Yes. Most baldness loci are autosomal, so your father passes on about half of them, and his thinning pattern is relevant to your own risk, though it does not guarantee yours.
Does hair loss come from your mother’s father?
Partly. Some X-linked risk can trace to a maternal grandfather, but most baldness genes are autosomal, so your father and both grandfathers matter too.
Is curly hair dominant or recessive?
Neither, in the simple sense. Many genes shape curl, so a child of one curly-haired and one straight-haired parent often ends up wavy or somewhere in between.
Is gray hair genetic?
Yes, but it does not come from mom or dad alone. Many genes from both sides influence when pigment cells slow down, and stress, nutrition, and lifestyle can speed the process.
Can traits skip a generation?
They can appear to. What actually happens is that a parent carries a genetic variant without visibly expressing it, and a child inherits a combination that crosses the expression threshold. It is a variation in expression, not traits disappearing and returning
Can genetic thinning be treated?
Yes. Minoxidil, finasteride, laser therapy, and hair transplant surgery are all established options. A specialist evaluation is the best starting point.
