Developmental, diachronic, and demographic analysis of cribra orbitalia in the medieval christian populations of Kulubnarti

Abstract

Previous analysis of cribra orbitalia in the medieval populations of Kulubnarti focused only on the presence or absence of the lesion relative to age, sex, and cultural period. Demographic consideration of the lesion was limited to a gross comparison of lesion frequencies and probabilities of dying by age group. The scope of the earlier work has been expanded in the present research to include the consideration of cribra orbitalia from a developmental, demographic, and diachronic perspective. The sample consisted of the same 334 crania analyzed by Van Gerven et al. ([1981] J. Hum. Evol. 10:395-408). All skulls showing the lesion were dichotomized as active or healing, and separate life tables were constructed for those with lesions and those without. The results demonstrate that active lesions are confined entirely to infancy and childhood with formation beginning as early as six months and ending by the twelfth year. This childhood pattern is consistent with the iron deficiency anemia hypothesis proposed by Carlson et al. ([1974] J. Hum. Evol. 3:405-410). Among young adults (16-40), healing lesions occur more frequently in males than females. In the older age categories, however, females exhibit a higher frequency of partially healed lesions than males. A life table comparison of those with and those without cribra orbitalia reveals a dramatic reduction in mean life expectancy for those with the lesion across the formative childhood years (birth-16). This reduction peaks at age 5 where 78% of the children exhibit lesions and where they, as a group, have a mean life expectancy 15.5 years below those without the lesion.