The Garisakang of Lowland Papua New Guinea
The Garisakang are an Indigenous population of approximately 500 individuals living in an isolated river valley in lowland Papua New Guinea. They currently live predominantly in a single community and continue to practice a mixed subsistence pattern based on small-scale horticulture, foraging, hunting, and fishing. Although the Garisakang are experiencing several notable changes (e.g., the first primary school in the region was introduced in 2011), modern infrastructure, healthcare, and integration into the regional/global market economy remain relatively minimal. Families (mixed polygynous) are large, physical activity levels are high, and the burden of infectious and parasitic disease is, unfortunately, heavy. This context provides opportunity to dramatically improve health outcomes while also addressing research topics informed by the small-scale, subsistence way of life and emerging market integration.
Our research among the Garisakang is carried out as part of the Garisakang Evolutionary Anthropology Project (GEAP, established in 2014) in direct collaboration with Dr. Martina Konečná (University of South Bohemia, Czech Republic) and the New Guinea Binatang Research Center (BRC). Current research projects are aimed at investigating the causes and downstream consequences of chronic stress, with a particular focus on the role of the hormone cortisol in mediating energetic relationships between socio-ecological variables, phenotypic plasticity (e.g., child development), and health. Among other findings, we have shown that the Garisakang have the lowest diurnal cortisol levels on record for any population. This is hypothesized to adaptively facilitate robust immune responses.
Our research with the Garisakang has been funded by the Czech Science Foundation and others. In addition to the BRC, we collaborate locally with the Papua New Guinea Institute of Medical Research, including with Drs. William Pomat and Gwen Vengiau.
Recent Key Publications
Global variation in diurnal cortisol rhythms: Evidence from Garisakang forager-horticulturalists of lowland Papua New Guinea – Stress, Urlacher et al. (2018).
Male social status and its predictors among Garisakang forager-horticulturalists of lowland Papua New Guinea – Evolution and Human Behavior, Konečná and Urlacher (2017).
Effect of chewing betel nut (Areca catechu) on the measurement of salivary cortisol levels. American Journal of Physical Anthropology, Konečná and Urlacher (2015).