March 29, 2005

Sexual dimorphism in 26 populations

Using the same data as before, I calculate the sexual dimorphism in 26 craniometric samples from around the world.

There are many ways to express sexual dimorphism, i.e., differences between men and women, which extend to both size and shape. I will limit myself to the simple measure of the average (over all traits) ratio of the male to the female mean (over all individuals).

Zulu 1.06
Egypt 1.06
Atayal 1.06
Zalavar 1.06
San 1.07
Hainan 1.07
Tasmanian 1.07
Moriori 1.07
Norse 1.07
Lake Alexandrina 1.07
Tolai 1.07
Dogon 1.08
Berg 1.08
Philippine 1.08
Yauyos 1.08
Teita 1.08
Buriat 1.08
Santa Cruz Island 1.08
North Kyushu 1.08
Ainu 1.09
Andaman Islands 1.09
Arikara 1.09
Hokkaido 1.09
Mokapu 1.09
Easter Island 1.09
Guam 1.09

So, it appears that these populations do not differ by much from each other in terms of sexual dimorphism. But, if we look at individual traits, the situation is much different. Men and women are most dimorphic (in decreasing order) in terms of their glabella projection (1.52), supraorbital projection (1.25), simotic subtense (1.2), mastoid breadth (1.18), mastoid height (1.16). So, it turns out that men and women can be quite different in terms of some traits, but not in terms of others.

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