Not playing Hamlet, but working with a skull.
You’re beavering away in your laboratory, DNA-ing this, mass-spectrometer-ing that, when the samples from the new crime scene come in. This time (to your relief) it’s fairly clinical: no blood and gore today. It’s a simple skull. The cops at the scene need to know as much about it as soon as possible; without you, they’re clueless. An initial observation doesn’t reveal much and it’s going to take a while to get dental impression results back.

Until then, what can skull analysis tell you? Quite a lot actually, but let’s start by determining the sex of your unfortunate victim.

 

The long bones and short of it.
Forensic anthropologists are trained to “read” skulls: they whisper silently to the contributing factors of death or trauma to the head. Here, we’re more concerned about questions of identification, and so we’ll acquaint ourselves with the external features of the skull.

Each individual’s skull is more or less different: yours will differ wildly to mine – including variations in cheekbone depth or height, thickness or thinness or other idiosyncrasies of size and shape. Such features that vary between individuals are called nonmetric features and are not normally measured.

 

Sexing skeletons
In the case of a long-decomposed and unidentified individual with no other affects on their person (e.g. a driver’s license or a passport), an anthropologist must make a quick inference as to what sex the person is. To this end, we’ve compiled a quick-and-easy guide to determining the sex of an unidentified person, using only their skull.

 

1. Examine the features of the skull.


Men generally tend to have thicker, heavier skulls. They are typically notably larger than female ones, generally speaking. Although this factor will not determine sex on its own, combined with the other features outlined below, it can give you a good indication of gender.

 

2. Look to the temporal lines.


The temporal muscle is a long band of tissue stemming from the parietal bone on the skull, and extending all the way to the mandible (the uppermost part of the jaw). The part of the skull where the muscle attaches (the temporal line) often has a more pronounced ridge in males than females.

 

temporal_muscle
The indentation lies under the muscle in this rendering.

 

3. Look me in the eyes and say that.


The eye socket area, when looking at the skull, is referred to as an orbit. The lower section of the orbit differs slightly between men and women. Women have a sharper ridge and males a slightly blunter surface to them.

 

4. Underneath the arches.


The superciliary arch or “monkey brow” is not very prominent in humans. Think of the prominent forehead of our primate friends and you’re probably thinking of this arch. It exists above the orbits, and comprises two arched elevations which are prominent medially. In males, there is usually some slight ridging here and you should be able to see some of it. In females, there is typically very little, or none at all.

superciliary arches
A page out of the old Gray’s Anatomy to help you locate the arches.

 

A word of warning, if you please.
You shouldn’t rely on one of these features in isolation to determine gender, but should look to a combination of the factors to give you a reliable indicator.

Sure enough, the differences between male and female skulls may be subtle and require a preriod of “calibration” in order to become proficient in seeing the differences. Once this is done, you should have a fairly well-honed ability to determine the sex of an individual from their skull.

 

Your Turn: There are other methods to discover it out there, but we’ve shown you what we think are the easiest. Know of any others? Tell us all about it in the comments.

Comments

comments

17 Responses

    • Ben

      Seriously. Why not SIDE by SIDE comparisons so we can OBSERVE the ACTUAL differences. You can do better than this.

      Reply
      • Douglas Filter

        Hello Ben, in our current format, we don’t do many illustrations in the body of an article, however, there are changes afoot. Stay tuned.

    • Douglas Filter

      Hello Joseph,

      That is an exact science, usually left to experts who will examine the specimen itself and take into consideration many data points from the investigation. We are considering another article which gets into how that is done, so keep watching our site!

      Reply
      • Amanda Benedict

        I have a valid question to ask. Do you have to be of a certain grade to join the F.O? Or in a certain Country, (as I am from Canada) to be accepted? I may have a low grade, but I am really good at Science. I am a really great listener, and I live to learn. I’m just asking about this, as I am in the processes of wanting to join. Please feel free to message me by e-mail. Thank you

    • N

      Hi Manu
      In terms of determining age solely from the skull the main areas investigated by a specialist are dentition and epiphyseal fusion. In the skull the primary port of call for fusion are the sutures. Age is very hard to approximate to an exact number and often experts will use ten to twenty years spans of age.

      Reply
  1. Shane

    I think another is looking at how far the zygomatic arch extends toward the external auditory meatus. IIRC, in males it ends before the external auditory meatus but in females extends beyond the external auditory meatus.

    Another is that males tend to have a more pronounced mastoid process than females. Although sex is apparently hard to discern by looking at just the mastoid process alone.

    Reply
  2. Aleksy Sogliani

    Its a very interesting topic for sure.
    I’m just not sure if i’m up to the blood and gore
    Even if you paid me a million pounds
    You wouldn’t hear a single sound!

    Reply
  3. Muhammad farooq wazir

    Farooq wazir
    how one differentiate between the skulls of male and female of age ranging from 12-16 years…as the supercilliary arches are not much prominent in males of that age

    Reply
  4. ronald

    Women’s skulls are smaller and rounder. like the image in black and white shows a female above. as to determining age – not sure

    Reply
    • Douglas Filter

      Ronald, with all due respect here, what are your qualifications and areas of study in regard to classifying skulls? Since the image is cut off above, we can’t really tell if it is rounded, oval shaped, oblong or what. Can you help us with any other characteristics you see in the photo – or would it be easier if you were able to see the real skull and make measurements and comparisons?

      Reply
  5. aaron

    Interesting article

    If there was a way to determine sex and age from a bone would that be useful to an anthropologist or forensic scientist?

    Reply
    • The Forensic Outreach Team

      Hi Aaron,

      Absolutely! There are several ways to infer the age and sex of an individual from skeletal remains and these are used to identify people who lack soft tissue on recovery. Hope this makes sense.

      Reply
  6. Julia

    It’s biological sex you are estimating, not gender. Also, you can’t speak of sex determination unless you’re using a statistical approach. I mean, you COULD, but that’s your professional reputation up there in the stand 😛 good article!

    Reply

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