Latitude, Digit Ratios, and Allen’s and Bergmann’s Rules: A Comment on Loehlin, McFadden, Medland, and Martin (2006)
Letter to the Editor
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In a recent article in this Journal, Loehlin, McFadden, Medland, and Martin ( 2006) investigated the relationship between latitude and digit ratio (2D:4D) first commented upon by Manning ( 2002). Manning suggested that inter-ethnic differences in mean digit ratio were a function of latitude, with populations at intermediate latitudes having the highest digit ratios and those at the equator and at high latitudes having the lowest. This trend was seen in the populations studied in Manning et al. ( 2000) (see Fig. 1, left panel). Higher digit ratios appeared to be more common at intermediate latitudes. However, the data collected by Loehlin et al. do not appear to fit this trend (Fig. 1, right panel).
KeywordsTestosterone Mental Rotation Digit Ratio Common Genetic Factor Rotation Ability
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We thank Amy Chee, Steven Hamblin, Frank Trovato, and Reginia Yan for comments and assistance.
- Australian Bureau of Statistics. (1998). How Australians measure up: 1995 (ABS Cat #4359.0). Belconnen: Australian Bureau of Statistics.Google Scholar
- European Communities. (2002). Health statistics: Key data on health 2002 (Cat #KS-08-02-002-EN-N). Luxembourg: Office for Official Publications of the European Communities.Google Scholar
- Eveleth, P. B., & Tanner, J. M. (1990). Worldwide variation in human growth (2nd ed.). Cambridge: Cambridge University Press.Google Scholar
- Katzmarzyk, P. T., & Leonard, W. R. (1995). Body mass, surface area and climate. American Journal of Human Biology, 7, 128.Google Scholar
- Loehlin, J. C., McFadden, D., Medland, S. E., & Martin, N. G. (2006). Population differences in finger-length ratios: Ethnicity or latitude? Archives of Sexual Behavior, 35, 739–742.Google Scholar
- Manning, J. T. (2002). Digit ratio: A pointer to fertility, behavior, and health. New Brunswick, NJ: Rutgers University Press.Google Scholar
- Manning, J. T., Barley, L., Walton, J., Lewis-Jones, D., Trivers, R. L., Singh, D. et al. (2000). The 2nd:4th digit ratio, sexual dimorphism, population differences, and reproductive success: Evidence for sexually antagonistic genes. Evolution and Human Behavior, 21, 163–183.PubMedCrossRefGoogle Scholar
- Roberts, D. F. (1978). Climate and human variability (2nd ed.). Menlo Park, CA: Benjamin-Cummings.Google Scholar
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