Sex Differences in Mobility and Spatial Cognition
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The fertility and parental care hypothesis interprets sex differences in some spatial-cognitive tasks as an adaptive mechanism to suppress women’s travel. In particular, the hypothesis argues that estrogens constrain travel during key reproductive periods by depressing women’s spatial-cognitive ability. Limiting travel reduces exposure to the dangers and caloric costs of navigating long distances into unfamiliar environments. Our study evaluates a collection of predictions drawn from the fertility and parental care hypothesis among the Twe and Himba people living in a remote region of Namibia. We find that nursing mothers travel more than women at any other stage of their reproductive career. This challenges the assumption that women limit travel during vulnerable and energetically demanding reproductive periods. In addition, we join previous studies in identifying a relationship between spatial ability and traveling among men, but not women. If spatial ability does not influence travel, hormonally induced changes in spatial ability cannot be used as a mechanism to reduce travel. Instead, it appears the fitness consequences of men’s travel is a more likely target for adaptive explanations of the sex differences in spatial ability, navigation, and range size.
KeywordsMobility Spatial cognition Parental care Namibia Fertility Sex differences
We would like to acknowledge the National Science Foundation SBE Office of Multidisciplinary Activities for supporting our research (Award #1329091), as well as the entire Spatial Cognition and Mobility (SCAN) group for their role in this project. In addition, we would like to thank the people of the Ovizorowe Valley for their hospitality and patience throughout the project.
- Collins, D., Busse, C., & Goodall, J. (2008). Infanticide in two populations of savanna baboons. In G. Hausfater, & M. S. B. B. Hrdy (Eds.), Infanticide: comparative and evolutionary perspectives (pp. 193–216). Piscataway: Aldine/Transaction (Originally published in 1984).Google Scholar
- Gaulin, S., Hoffman, H., et al. (1988). Evolution and development of sex differences in spatial ability. In L. L. Betzig, M. B. Mulder, & P. Turke (Eds.), Human reproductive behaviour: A Darwinian perspective (pp. 129–152). Cambridge: Cambridge University Press.Google Scholar
- Gregor, T. (1987). Anxious pleasures: The sexual lives of an Amazonian people. Chicago: University of Chicago Press.Google Scholar
- Hill, K., & Hurtado, M. (1996). Ache life history: The ecology and demography of a foraging people. Hawthorne: Aldine.Google Scholar
- MacDonald, D., & Hewlett, B. (1999). Reproductive interests and forager mobility. Current Anthropology, 40(4), 501–524.Google Scholar
- Murphy S, Xu J, Kochanek K (2010) Deaths: Final data for 2007. National Vital Statistics Reports 61(4). Centers for Disease Control and Prevention. Available at http://www.cdc.gov/nchs/data/nvsr/nvsr61/nvsr61_04.pdf.
- Unity (2014) Unity 3D. Available at www.Unity3D.com.
- Vashro L (2014) Residence and childcare assistance among the Twe. PhD thesis, Department of Anthropology, University of Utah, Salt Lake City.Google Scholar
- Viljoen P (1982) The distribution and population status of the larger mammals in Kaokoland, South West Africa/Namibia. Cimbebasia (A) 7(2):5–33 Windhoek Staatsmuseum.Google Scholar