Lateralization and reaching skill related: results and implications from a large sample of Long-Evans rats.

Limb preference and reaching success were examined in 580 Long-Evans rats. Most rats displayed a strong asymmetry. Although slightly more rats used the left limb than used the right limb, the difference was not significant. Thus, Long-Evans rats do not show dominance with respect to limb use. There was a significant correlation between the degree of lateralization and success of limb use. This relation suggests either that endogenous factors contributing to limb lateralization also contribute to motor skill or else the use of a lateralized reaching strategy facilitates the development of skill in reaching. The results are discussed in terms of their methodological implications for studies of selective breeding and strain differences and also in terms of their significance for understanding the evolutionary basis of lateralization and dominance.