We found the discussion of latitude and digit ratios by Hurd and van Anders (2007) most interesting, and their finding of a strong negative correlation between average heights and digit ratios across ethnic groups (their Fig. 2) quite provocative. We heartily endorse their call for further research on the topic. Those thinking about this matter might wish to keep in mind that height and digit ratio do not appear to be correlated for individuals within populations. Lippa (2003) reported correlations between the 2D:4D ratio and self-reported height in his California sample as .03 for right hands and .01 for left hands for 299 males, and .11 in both cases for 414 females.

In response to the Hurd and van Anders note, we have calculated the correlations between height (measured at age 12) and 2D:4D (measured at various ages) for both right and left hands for the Australian sample described in our article (Loehlin, McFadden, Medland, & Martin, 2006). This was a sample primarily of Caucasian–mostly British–ancestry. The correlations for right and left hands were −.02 and .06, respectively, for 575 males, and −.04 and −.02 for 624 females—non-significantly different from zero. A unified explanation of ethnic group differences, sex differences, and individual differences promises to be challenging indeed.