The 82nd Annual Meeting of the American Association of Physical Anthropologists (2013)

Aging Methods across Populations: Focus in Nigeria


1Anthropology, Univeristy of South Florida, 2Anthropology, University of Illinois at Urbana – Champaign

Thursday Afternoon, 301E Add to calendar

Building on a body of work by Jantz, Konigsberg, and Kimmerle (2008) which addressed questions about population variation in human identification, models for aging Nigerian populations are investigated. Demographic data for n=2,590 cases and biometric scores (n=356) for the pubic symphysis and fourth ribs, scored in the manners of Suchey-Brooks and Iscan and co-workers, were collected for identified individuals autopsied at LASUCOM, Nigeria. Overall the average ages and general age ranges for each phase are lower than that of the original methods. The Nigerian samples have a lower mean age at death, though the overall range is consistent, whereas the American sample tends to be slightly older. Comparing the distributions of the samples through independent sample t-tests, reveals they are significantly different, for both male and female groups, well below the 0.05 level. Interestingly, the mean difference is far less between Nigerians and Americans, 4.35 years, than it is among Nigerian and Balkan samples, 13.6 years. To calculate age-at-death parameters that can be used by investigators in the field – a Bayesian statistical approach is used. Combined parameters for both traits are calculated. For the 321 Nigerian individuals having both rib and pubic symphysis data, an “R” script “lrage.viewer.biv” applies single trait models for the rib and pubic symphysis stages and combines these with the total Nigerian age-at-death distribution (n=2,461). Of the 296 individuals in a bootstrap sample, 141 (47.63%) had ages that fell within their stated 50% HPD. This is not significantly different from the 50% expected (p=0.4158).

This project was supported by Award No. NIJ 2008-DN-BX-K163 awarded by the National Institute of Justice, Office of Justice Programs, U.S. Department of Justice. The opinions, findings, and conclusions or recommendations expressed in this presentation are those of the authors and do not necessarily reflect those of the Department of Justice.

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