David R. Samson, Ph.D. ~ Evolutionary Biologist

Research Statement: I investigate the link between sleep, health, and cognition in human and non-human primates

Humans are a remarkable species. We live in large social networks, persist in inhospitable places, fashion complex tools, and communicate using language. While we exhibit many morphological and behavioral differences to other primates – our cognitive capacity likely played a crucial role in our success. My research investigates the biology, ecology, and evolution of primate sleep. I believe the effects of sleep on our lineage were profound. For example, in humans, sleep is critical for immune strength, working memory, attention, decision-making, and visual-motor performance, yet how sleep affects such processes remains unknown for most non-human primates. To investigate this research question, I use pioneering, non-invasive technology to study human and non-human primates with a broad phylogenetic scope. In addition, I engage with the emerging field of evolutionary medicine by using my findings to understand human sleep disorders within an evolutionary framework. The ultimate goal of my research is to further our understanding of human evolution.




  • Bray, J., D.R. Samson, and C.L. Nunn. 2016. Activity patterns in seven captive lemur species: evidence for cathemerality in Varecia and Lemur catta? American Journal of Primatology - In press.
  • Samson, D.R., G.M. Yetish, A.N. Crittenden, I.A. Mabulla, A.Z.P. Mabulla, and C.L. Nunn. 2016. What is segmented sleep? Actigraphy field validation for daytime sleep and nighttime wake. Sleep Health 2: 341-347 [PDF]
  • Nunn, C.L., D.R. Samson, and A.D. Krystal. 2016. Shining evolutionary light on human sleep and sleep disorders. Evolution, Medicine, and Public Health doi:10.1093/emph/eow018 pp. 187–202 [PDF]
  • Samson, D.R. and C.L. Nunn. 2015. Sleep intensity and the evolution of human cognition. Evolutionary Anthropology 24(6): 225-237 [PDF]
  • Samson, D.R. and R.W. Shumaker. 2015. Pre-sleep and sleeping platform construction behavior in captive orangutans (Pongo spp.): Implications for ape health and welfare. Folia Primatologica 86(3): 187–202 [PDF]
  • Samson, D.R. and R.W. Shumaker. 2015. Orangutans (Pongo spp.) have deeper, more efficient sleep than baboons (Papio papio) in captivity. American Journal of Physical Anthropology 157(3): 412–427 [PDF]
  • Samson, D.R. and K.D. Hunt. 2014. Is chimpanzee (Pan troglodytes schweinfurthii) low population density linked with low levels of aggression? Pan Africa News 21: 15–17 [PDF]
  • Samson, D.R., D. Hurst, and R.W. Shumaker. 2014. Orangutan night-time long call behavior: Sleep quality costs associated with vocalizations in captive Pongo. Advances in Zoology 1: 1–8 [PDF]
  • Samson, D.R. and K. D. Hunt. 2014. Chimpanzees preferentially select sleeping platform construction tree species with biomechanical properties that yield stable, firm, but compliant nests. PLOS ONE 9: 1–8 [PDF]
  • Samson, D.R. and R.W. Shumaker. 2013. Documenting orangutan sleep architecture: sleeping platform complexity increases sleep quality in captive Pongo. Behaviour 150: 845–861 [PDF]
  • Samson, D.R., M.P. Muehlenbein, and K.D. Hunt. 2012. Do chimpanzees (Pan troglodytes schweinfurthii) exhibit sleep related behaviors that minimize exposure to parasitic arthropods? A preliminary report on the possible anti-vector function of chimpanzee sleeping platforms. Primates 54(1): 73–80 [PDF]
  • Samson, D.R. 2012. The chimpanzee nest quantified: Morphology and ecology of arboreal sleeping platforms within the dry habitat site of Toro-Semliki Wildlife Reserve, Uganda. Primates 53(4): 357–364 [PDF]
  • Samson, D.R. and K.D. Hunt. 2012. A thermodynamic comparison of arboreal and terrestrial sleeping sites for dry-habitat chimpanzees (Pan troglodytes schweinfurthii) at the Toro-Semliki Wildlife Reserve, Uganda. American Journal of Primatology 74(9): 811–818 [PDF]
  • Husmann, P.R. and D.R. Samson. 2011. In the eye of the beholder: Sex and race determination using the human orbital aperture. Journal of Forensic Sciences 56(6): 1424–1429 [PDF]
  • Samson, D.R.. 2006. Stones of contention: The Acheulean handaxe lethal projectile controversy. Lithic Technology 31(2): 127–136 [PDF]

Selected Published Journals

Curriculum Vitae



David Samson is a scientist, educator, and lecturer. He earned his Ph.D. at Indiana University, is a Post-doctoral Associate working in the Nunn Lab at Duke University, and has worked with wild chimpanzees, zoo-dwelling orangutans, and sanctuary living lemurs. As an evolutionary biologist interested in human evolution, he is currently investigating the link between sleep and cognition in primates. David has lived in the Toro-Semliki Wildlife Reserve in Uganda, habituating wild chimpanzees and climbing African Ironwood trees – a favored sleeping spot for Semliki chimps – to further our understanding of ape sleep sites. At the Indianapolis Zoo, he studied the sleep patterns of orangutans and was part of a team that tested the effects of sleep on touch-screen cognitive tasks. Currently, he is leading similar research projects at the Duke Lemur Center, working with the world’s largest and most diverse collection of lemurs outside of Madagascar. As a National Geographic Grantee, he will be extending this work to one of the last hunter-gatherer groups in Africa – the Hadza of Tanzania - as well as other small-scale societies. In his spare time, Samson is a practitioner of a medieval martial art in the Society of Creative Anachronism.

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  • Panel: Hacking the Brain

    Washington, D.C., Grosvenor Auditorium: Sleep and the Primate Mind