I lurk on baby message boards, and one thing that the mommas-to-be are always talking about is the Skull Theory.
Skull Theory is an at-home technique for predicting gender, although fans claim it has a 92% accuracy rate. Basically, you compare your baby’s ultrasound profile picture to the diagram shown here, looking for certain ‘male’ or ‘female’ markers in the shape of the skull.
Male and Female Cranium Differences:
Most important skull differences between men and women are indicated by the letter value on the figure linked to above and described below:
A. The mans cranial mass is more blocky and massive compared to the females which is rounder and tapers at the top.
B. Temporal Ridge – runs along the outer side of the upper skull creating the square shaped of the upper head. More prominent in men than women.
C. A woman’s supraorbital margin (the ridge above the eyes) is sharper, while the males is rather round and dull.
D. The Zygomatic bone (the cheekbone that lies under the lower eye ridge) is more pronounced on the male skull.
E. The Mandible (lower jaw) bone of a woman is rounded, while the male’s is squared.
F. Frontal bone forehead structure terminates at the brow. The male forehead is lower and more slopping.
G. Men have a deeper cranial mass.
H. The supercilary arch is large and pronounced in the man.
I. A males gonion (most posterior inferior point on angle of mandible) is more flared out and sharply angled.
J. The teeth of men tend to be larger.
Note that it was impossible to find an active, original source for the picture and information quoted above (it is mostly just re-posted on baby forums, but I suspect it came from this now defunct site).
Since this gender prediction test only seems to exist on baby forums, I’m not sure how scientifically accurate it is, but it sure is fun to read about… And although we’re not planning to find out the sex at tomorrow’s anatomy scan, I can’t help but think I’ll be looking a little more closely at the shape of the head.
If you know your baby’s gender and have a second trimester ultrasound picture, was the Skull Theory correct for you?