Water-escape in weanling rats: A link between behaviour and biological fitness

Relationships between behaviour, measured in many standard laboratory settings, and biological fitness are often obscure. By making inferences from the genetic architecture revealed in psychogenetic studies, links between behaviour and biological fitness can be forged. To support these inferences, information is needed about the genetic architecture underlying behaviour which has unequivocal links to fitness. In this study, water-escape in rats is related a priori to fitness. Weanling rats from the Roman High Avoidance and Roman Low Avoidance strains and their reciprocal F₁ crosses are tested in a water-escape apparatus. A strong directional dominance found for rapid escape is in keeping with the assumptions made and confirms the test as a useful tool for psychogenetic studies of rats.