The 89th Annual Meeting of the American Association of Physical Anthropologists (2020)

Early 20th century polio mortality among non-Māori in New Zealand reflects flattened SES gradient


Anthropology, School of Social Sciences, University of Auckland

April 16, 2020 , Platinum Ballroom Add to calendar

New Zealand in the late 19th and early 20th centuries had a reputation as a ‘working man’s paradise’ for Pākehā (non-Māori, settlers), with extensive social mixing, low industrialization, relatively low population densities, and high home ownership rates. However, some degree of social gradient remained. The traditional polio model depicts a positive relationship between the disease and socioeconomic status (SES), with higher SES associated with exposure to the poliovirus beyond infancy/early childhood and consequent higher mortality rates. The research question addressed here is whether New Zealand’s SES gradient was strong enough, and linked closely enough to living conditions (and thus differential virus exposure), to produce differential polio mortality.

This study uses occupation data from the New Zealand Census and non-Māori death registrations for the polio epidemics of 1916, 1924–25, and 1936–37. Polio deaths were classified by father’s occupation using the Caversham Project scheme, which includes nine collapsible urban occupational strata and codes rural occupations separately. Non-parametric tests showed limited evidence of either differential mortality or differences in age at death among collapsed urban strata. For 1916 only, the rural group had a higher proportion of deaths (χ2 (1, n = 95) = 8.341, p = .0039, φ = .30) and higher age at death (Mann-Whitney U = 828.00, p = .026, r = -0.23), indicating that rural Pākehā were more isolated from poliovirus infection prior to 1916 but faced similar risk afterwards. These results suggest that polio mortality reflected the flatter SES gradient of Pākehā New Zealand society.

This research was funded by a 2016-2018 New Staff Faculty Research Development Fund (FRDF) grant from the University of Auckland Faculty of Arts.

Slides/Poster (pdf)