A test of Hartnett's revisions to the pubic symphysis and fourth rib methods on a modern sample

Estimating age at death is one of the most important aspects of creating a biological profile. Most adult age estimation methods were developed on North American skeletal collections from the early to mid-20th century, and their applicability to modern populations has been questioned. In 2010, Hartnett used a modern skeletal collection from the Maricopia County Forensic Science Centre to revise the Suchey-Brooks pubic symphysis method and the İşcan et al. fourth rib methods. The current study tests Hartnett's revised methods as well as the original Suchey-Brooks and İşcan et al. methods on a modern sample from the William Bass Skeletal Collection (N = 313, mean age = 58.5, range 19-92). Results show that the Suchey-Brooks and İşcan et al. methods assign individuals to the correct phase 70.8% and 57.5% of the time compared with Hartnett's revised methods at 58.1% and 29.7%, respectively, with correctness scores based on one standard deviation of the mean rather than the entire age range. Accuracy and bias scores are significantly improved for Hartnett's revised pubic symphysis method and marginally better for Hartnett's revised fourth rib method, suggesting that the revised mean ages at death of Hartnett's phases better reflect this modern population. Overall, both Hartnett's revised methods are reliable age estimation methods. For the pubic symphysis, there are significant improvements in accuracy and bias scores, especially for older individuals; however, for the fourth rib, the results are comparable to the original İşcan et al. methods, with some improvement for older individuals.