Hereditary balding is complicated, and the popular notion that it's inherited solely from your mother is incorrect.

Blaming a single gene for baldness is too simplistic — in reality, your chances of losing hair are determined by a complex host of genes from your mother and father, along with some environmental factors.

Some genes that determine early baldness in men might be carried on the mother's x-chromosome.



When it doubt, blame your mom for your problems...right?

Actually, science says you can't even blame your mother's genes for a bald head.

For years, many people have believed the myth that the genes for male pattern baldness are passed down from a mother to her son on her x-chromosome. The conventional wisdom has been that men could simply take a look at the heads on their mom's side of the family and get a pretty good indication of how theirs might wind up looking.

But doctors say it's more accurate to blame both of your parents for thinning hair.

"To assess your chances for hair loss, look at all relatives in your mother's and father's families," Dawn Davis, a doctor from the Mayo Clinic's dermatology department, wrote in a blog post.

There are a couple of reasons that's true. First, scientists still aren't sure exactly which genes determine whether we lose hair and where those genes come from, but they think both sides of the family contribute. Second, your mom has two x-chromosomes, which makes it difficult to look to any one family member for clues about your hair's future.

Why we lose hair as we age

The scientific term for common hair loss is androgenic alopecia. If you have it, you're not alone: roughly half of all adults will lose some hair by the time they're 40.

Hairs last about two to three years on our head, then fall out and get replaced with new ones in a months-long cycle. When a hair falls out and isn't replaced — or gets replaced with a much thinner hair — then we start to go bald.

The specific factors that determine how hair-free someone's head will be are still somewhat mysterious. Scientists believe the condition is mostly genetic, and caused by changes in our sex hormones.

One recent 2018 scientific review hypothesized that people likely lose their hair as the concentration of one sex hormone (dihydrotestosterone) increases in the tissue on their heads. That hormone leads hairs to become thinner and even stop growing out of the follicles altogether, which might be the key mechanism at work with genetic hair loss. But scientists still aren't quite sure how it works.

What scientists have discovered about male pattern baldness

Even though it's not totally your mom's fault, her genes might play a role, especially if you go bald before middle age. One 2005 German study suggested that balding before the age of 40 may be dictated by a gene on the X-chromosome, meaning that the predisposition would come from a mother's side of the family.

The researchers hypothesized that men who inherited the alleged balding "gene" from their moms would be predisposed to have more androgen (a male sex hormone) receptors on their scalp, and more likely to go bald early as a result.

But Professor Markus Nöthen, one of the researchers leading the study, said in a release that there were also "indications that other genes are involved which are independent of the parents' sex."

Nöthen did a follow-up study on more than 600 German men in 2008, and found that a location on Chromosome 20 had a "strong effect" on early onset male pattern baldness. That's a clue that both a mother's and a father's DNA are involved in baldness genes.

Non-genetic factors seem to be at play, too. A 2013 study of more than 3,100 Korean patients found that smoking and drinking can have an impact on whether people lose their hair early.

The lingering mystery of baldness explains why it's been so difficult to create a gene-therapy "cure" for baldness, though scalp scientist Shirley McDonald told Business Insider that's the new holy grail for hair scientists.

Until then, there are only a couple proven treatments that fight or slow balding: Rogaine (generic name: Minoxidil) and Propecia for men (generic name: finasteride).

Other than that, the best strategy may be just to own one's shiny scalp — scientists have found that people tend to describe bald men as both stronger and taller when they shave their heads.