Genetic Approaches

Abstract

In the search for a mechanism for laterally biased behaviors, theorists have been fascinated by the right-sided bias in human populations. This bias appears for hand, foot, eye, and ear use, as shown in Chapter 3, and appears to be a statistical constant for our species. Evidence available in the historical record suggests that humans have displayed a relatively constant proportion of right-handedness since the Paleolithic era, as noted in Chapter 1. Also, the proportion of right-handedness is relatively constant, regardless of geographical considerations (see Chapter 6). Such consistency, despite cultural and historical factors, leads to the suspicion that dextral lateral preference behaviors are part of our biological heritage and are therefore of genetic origin.