In his book The Human Body (1962), Isaac Asimov notes that, except for slightly different shapes of bones, a man’s skeleton is the same shape and configuration as a woman’s. Also, in the Time-Life Science Series book Matter is a drawing suggesting that the female pelvis is more nearly perpendicular to the ground, while the male pelvis is clearly tilted forward; and in the recent “got milk?” ad showing a fluoroscope view of three hospital workers, one female and two male, it shows the female’s rib cage as being straight-sided (that is, ribs don’t “bulge” to the sides in the middle of the rib cage) while the males’ rib cages do bulge outwards. Is this difference–the tilt of the pelvis and the general shape of the rib cage–valid as a way to idenfity a skeleton as male or female?
I don’t know about the ribs, but the pelvis certainly is. A female’s pelvis is wider than a males, since she’s got to bear children.
I think there is a difference to the length/width ratio in the long bones of males and females, but this is pretty much a WAG. I’ve also heard a skilled forensic pathologist can tell gender by the features of the skull.
To hijack, a teacher once told me that there is a significant difference in the curvature of the femur in black and white people. Any validity to that?
I am not a forensic anthropologist, but I have studied anatomy.
Yes, there are differences between the male and female skull on average. In particular, men tend to have heavier brow ridges (women may not have them at all), and the angle of the lower jawbone also show gender-related differences. Specifically, this angle tends towards being a right angle in adult males, and in women tends to be obtuse. This is NOT 100%, however, but on average. Combined with other skeletal features, it may allow idenfitication of gender even without the pelvis.
Size also matters - we all know men tend to be bigger than women. As a general rule, more six foot skeletons belong to men than to women, although, again there are exceptions. A six foot women’s skeleton may, in some ways, resemble that of typical male more than her five foot sisters, and on the flip side, that of a small male of five foot may have some “feminine” tendencies. That’s because some of the “male” and “female” traits have more to do with overall size than with gender. The “length/width” ratio of the long bones is dependent to a great deal on overall size, with some influence from exercise. As a result, this tends to show gender differences but a tall, Olympic female athelete is going to have a “masculine” skeleton in this way due to all that physical development. A short, sedentary man will have opposite tendencies. There have been instances where crime victims were described with the wrong gender due to such features so it is never 100%
The ribcage thing is a new one - I’ve seen actual human skeletons of all shapes, sizes, genders, and races and can say that while ribs and their cages varying considerably from one individual to the next, there are, to the best of my limited knowledge, no typically “male” or “female” rib characteristics.
There are also racial differences, despite the recent fad among some people to assert there are no races. There is, indeed a difference in the femur (upper leg bone) between Caucasians and Africans involving a slight twist. Once again, this is not 100%. First of all, even though the trait is extremely common in Africa, I believe some of the minority populations, like the KhoiSan and Horn of Africa tribes lack this. There has also been considerable mixing of populations over time, resulting in the occassional Caucasian showing up with this feature. Especially in the US, where a lot more racial mixing has gone on that most people want to admit to
Racial differences also show up in the skull, accounting for the faces we’d identify as “Asian” or “African” or “European”. These show up in the teeth, cheeckbones, nose hole, and eye holes of the skull, in addition to the overall shape varying somewhat between populations.
Broomstick… I love you. I have never been proven (reletavily) right twice in one day. You made my day.
I always get my anatomical data from Madison Avenue.
(Does anyone use “Madison Avenue” to refer to the advertising industry anymore, or am I showing my age again?)
FWIW there appears to be some difference between the articulation of the male/female elbow as well.
IIRC, when I was involved with the Archery Club at college, it became apparent that female students were more likely to suffer discomfort from the bow string striking the inner aspect of the elbow on loose instead of the bracer (leather guard) worn on the left forearm. (This is all on average of course, and assumes thoughout that the archer is right-handed.)
I have just checked my memory by comparing my elbow with my wife’s, and her elbow is bent far more towards the bow than mine. It is easy to check, just hold the left arm straight out sideways from the shoulder with the fist vertical.
This difference is reflected in the equipment available for women, which includes full-arms-length bracers and body bracers which also cover the left breast (a much better solution than that adopted by the Amazons).
Also:
Many but not all men and extremely few women supposedly (I cannot vouch for the accuracy of this) have an occipital ridge – the slight bulging out at the base of the back of the skull.
Women allegedly tend to have wider hipbones than men, there being a nearly parallel alignment of the lateral-ventral aspect of the hipbones in men while women have a more pronounced oblique angle between them. (Note that this is stereotypical, not necessarily the case for every person of that sex.)
The occipital ridge varies by ethnicity. In my family, EVERYONE has one, male and female alike. Mine is quite pronounced, despite my double X chromosome. Other groups have them not at all.
Keep in mind that some of these “averages” are based on Western Europeans.
As another example - it is quite common to find supra-orbital ridges (what I called “brow ridges” in an earlier post) in European men, and even quite a few women, but this same feature may be non-existant in some Asian populations in either gender.
…including a correction. :o I should have said that the female pelvis is mopre nearly parallel to the ground, not perpendicular. :o
In the Matter book, in the chapter on radioactivity, is a reproduction, from an old issue of Life, of an old drawing by Charles Dana Gibson titled “That Delicious Moment–when you find you are to take to dinner the girl who yesterday refused you.” In the drawing are three men and three women; below this is a version of the same scene, with an explanatory caption; on the male skeletons the obturator foramina (“stopped-up holes,” Latin) on the bottom of the pelvises are clearly visible; on the female skeletons the pelvis is, as I noted, not titled and the foramina are not visible. (The name arose from the fact that these “holes” are, of course, covered with membranes in a living person.)
A woman I knew from high school who was, and still is (at age 52) quite a beauty, has so-called “racial” characteristics in her skull. She has a high forehead and high cheekbones, like her mother (deceased :() and mother and daughter have ascribed this to American Indian ancestry. I once commented that she has the high forehead because–well, with her talents and skills she measures 120" around the brain…
In a photo of her wearing a bikini, the bottom of her rib cage is slioghtly visible on her torso; she has been quite athletic and healthy most of her life.
You wouldn’t happen to have a picture on ya Dougie?
FWIW, in my 9th grade health class we learned that the most reliable way to tell male and female skeletons apart was that male skeletons go to the bathroom standing up while female skeletons go to the bathroom sitting down. Granted, this was the opinion of a gym teacher and not a forensic anthropologist, but since I have yet to see countervailing evidence, I use this myself as a working hypothesis.
Originally posted by Thinktank
Oh, I wish I did…I’d be only too happy to post it–if I had one and had her permission. For my own part I don’t need a picture; she is permanently engraved in my memory.
In a college zoology class(1968,) with an accent on human anatomy, the prof said that the elbow joint is telling. That is, the typical female elbow will hyperextend, and the male’s won’t. He said the way the knob on the end of the ulna fits into the hollow in the humerus will tell you the gender of the bones.
Sorry Nott, I’ve got to prove you wrong! I’m female, and my elbows hyperextend… coincidentally, so can my fiancee’s, who happens to be sitting this very moment on the couch watching that friggin basketball game that everyone’s going ape shit over. I finally got his attention long enough for him to extend his arm, and lo and behold, it hyperextends! And believe me, there is no way my fiancee is female, or a transvestite! 
Sorry liirogue but a single case does not prove Nott (or his professor) wrong.
The prof stated that his observation applied to typical female/male elbows - not all.
If this characteristic (hyper-extension) has the usual bell-curve distribution then there is plenty of room to allow for overlapping male/female traits without disproving the comment on the typical.
Aww dangit! And here I thought I was actually on to something!
:sulks off to her corner:
Would another difference be in the hands? I remember learning in AP Bio of a gender difference in the lengths of certain fingers, which was confirmed in all but one case among the dozen or so students in the class (and yes, of course we mercilessly teased the one guy who was the exception). That would have to be a skeletal difference, would it not?
<i>Scrubs</i>. Great show.
I was an anthropology major in college and was prepared to answer, but Broomstick already summed it up pretty well. The only thing I would add is that in addition to a more pronounced brow ridge, men’s skulls tend to have deeper palates, more pronounced mastoid processes (the skull bump behind the ear), slightly smaller ocular orbits (eye holes) and slightly more pronounced occipital protruberances (bump in the back of the head).
Great post Broomstick-