James Cheverud: Human Skull Modification

Modified human skulls in the Field Museum, Chicago.

The photograph depicts modified skulls studied by Prof. James Cheverud of the Dept. of Anthropology and School of Medicine. Throughout human history various peoples around the world have purposely modified the shape of their children's cranial vaults to obtain a culturally pleasing shape, different shapes being favored by different cultures. This is accomplished by binding the cranial vault of infants and juveniles to restrict growth in some dimensions. It results in overgrowth of other cranial vault dimensions. This process has no known effects on overall brain size or mental ability. Indeed modern Western Anglo-American culture has a preference for rounded, symmetrical cranial vaults and physicians prescribe specialized helmets to reshape the cranial vault if it too strongly deviates from idealized form.

Cultural modification of cranial vault shape provides a natural experiment for studies of cranial growth, especially concerning processes by which modifications of the cranial vault affect the growth of the cranial base and face. In a series of studies comparing modified with unmodified crania from a variety of populations with different kinds of cranial modification, we found that modifications of the cranial vault were transferred to the face through the cranial base. Thus modifications producing a short, wide cranial vault resulted in a short, wide, shallow face while modifications producing a long, narrow cranial vault resulted in a long, narrow, deep face. These results demonstrate both the adaptation of facial growth to primary cranial vault morphology and the integration of morphology in different parts of the skull with consequences for evolutionary, clinical, and developmental studies.

Citations (Cheverud et al., 1992 and Kohn et al. 1993 are the primary papers):

Kohn, L. A. P., S. Leigh, S. Jacobs and J. Cheverud 1993 Effects of annular cranial vault modification on the cranial base and face. American Journal of Physical Anthropology, 90: 147-168.

Konigsberg, L., L. A. P. Kohn and J. Cheverud 1993 Cranial deformation and nonmetric trait variation. American Journal of Physical Anthropology, 90: 35-48.

Cheverud, J., L. A. P. Kohn, L. Konigsberg and S. Leigh 1992 The effects of fronto-occipital artificial cranial vault modification on the cranial base and face. American Journal of Physical Anthropology, 88: 323-346.

Cheverud, J. and J. Midkiff 1992 The effects of fronto-occipital cranial reshaping on mandibular form. American Journal of Physical Anthropology, 87: 167-172.