The Norway rat is an indispensable model organism. Behavioral studies on rats usually concentrate on a single trait without considering how different behaviors are linked to each other and whether there are differences in this respect between rat strains or sexes. This study aims to describe the personality structure of the Norway rat, and investigate if the structure of personality varies between sexes or populations, using owner assessments of pet rats. Rat owners from three countries filled out a questionnaire which was analyzed using structural equation modeling. The data were divided between the sexes and populations, resulting in six groups. Preliminary exploratory factor analysis was first conducted on the most numerous group to form a hypothesis about the personality structure, after which confirmatory factor analysis was used to discover differences between groups. A three factor model consisting of the components activity, tameness and anxiousness fit all groups. Both quantitative and qualitative differences were found between sexes, especially with respect to the trait activity. If neglected, the sex differences compromise the generality and reliability of behavioral research on rats. Population differences were negligible. The results underline the importance of considering the sex of the animal as well as its individual characteristics when assessing its wellbeing, behavioral requirements or suitability for a certain task or research experiment. Using a method adopted from human personality research produced meaningful results consistent with previous reports on rodent personality.
|Publication Title||Applied Animal Behaviour Science|
|Cite this work||
Researchers should cite this work as follows: