Women have an extra rib.

1. Myth’s origin: a biblical story turned into anatomy

The persistence of the “extra rib” belief traces to the Genesis account in which Eve is fashioned from one of Adam’s ribs; that narrative was converted by some readers into the biological claim that females have more ribs than males ^{[4] [1]}. Answers in Genesis documents how the story is used culturally to “prove” scripture by asserting a physical difference in rib count ^[4]. Popular websites and health explainers repeatedly flag the same origin when debunking the claim ^{[1] [2]}.

2. What anatomy and mainstream medical sources say

Standard human anatomy lists 12 pairs of ribs (24 total) as typical for both men and women; authoritative medical summaries and recent debunking pieces state there is no sex-based rule that women possess an extra rib ^{[1] [3]}. Multiple fact-focused articles published in 2025 explicitly state the myth is medically unfounded and that rib counts are consistent across sexes ^{[1] [2] [5]}.

3. Rare exceptions: extra or missing ribs are congenital, not gendered

Congenital variations exist: some people are born with an extra cervical rib (an extra rib arising high in the neck) or may lack a 12th rib; these anomalies are uncommon (cervical ribs affect roughly 0.5–1% of people) and are not limited to one sex ^{[2] [3]}. Health reporting notes that such anomalies can cause conditions like thoracic outlet syndrome but do not validate any broad male/female rib-count difference ^{[3] [6]}.

4. Social life of the myth: why it endures

The myth persists because it offers a simple, literal confirmation of a meaningful cultural narrative; it’s easy to repeat in classrooms, pulpits, and casual conversation, and that social momentum outlasts anatomical facts ^{[4] [1]}. Websites and blogs continue to encounter and debunk it, showing how quickly folklore can masquerade as biology when tied to powerful origin stories ^{[1] [7]}.

5. Competing claims and where sources disagree

Most mainstream medical and science-oriented sources reject the sex-based difference; some trivia posts and informal pieces have even suggested men may be more likely to have extra ribs, indicating confusion in popular accounts ^{[3] [8]}. Creationist resources treat the question as a rhetorical or apologetic point rather than a scientific one, framing the myth as a cultural argument for scripture ^[4]. Available sources do not mention any peer-reviewed anatomical study that supports a routine sex difference in rib count.

6. Modern related practices that confuse the issue

Cosmetic and surgical stories about rib removal or “waist narrowing” — e.g., procedures removing or reshaping lower (often floating) ribs — add further misunderstanding by showing that ribs can be surgically altered, but these operations do not reflect innate sex differences in rib number and are controversial medically and ethically ^[9]. Reporting on such procedures can make ribs seem more malleable or variable than they are by default ^[9].

7. Bottom line for readers: fact vs. folklore

The medical and anatomical consensus is straightforward: men and women are typically born with the same number of ribs — 12 pairs — and rare extra or missing ribs occur sporadically in both sexes ^{[1] [3] [2]}. Use of the Adam-and-Eve passage as biological evidence misunderstands genetics and anatomy; Answers in Genesis itself notes the logical flaw of expecting offspring to inherit a parent’s acquired loss ^[4]. Readers should treat the “women have an extra rib” claim as cultural folklore, not anatomy.

Limitations: this report synthesizes the provided sources only; it does not reference any anatomical textbooks beyond those quoted in the supplied articles, and available sources do not mention large-scale, peer‑reviewed anatomical surveys that might quantify sex differences beyond the cited anomaly rates ^{[2] [3]}.