Examining personality dimensions in rats using a caregiver questionnaire

Measures of individual behavioural differences (personality) are highly valuable in many areas of ethology, particularly studies of animal emotion and welfare. However, there are limitations to current behavioural tests of personality. Caregiver questionnaires may provide a complementary approach to overcome some of these limitations and provide a richer insight into personality. Drawing on previous studies, we developed a questionnaire in which caregivers were asked to rate the extent to which a given adjective/term described a rat under their care. We then used factor analysis to identify personality dimensions and assess whether those dimensions mapped to rat sex, rat age, number of companions, predator exposure, or owner experience. We obtained usable data from 296 rat caregivers and identified six personality dimensions: tameness, shyness, liveliness, interspecific sociability, inquisitiveness, aggressiveness. These dimensions are, with the exception of 'inquisitiveness', in line with previous studies and the broader literature on personality in non-human animals. With the exception of shyness, which was significantly associated with sex and owner experience, we found no strong evidence for a relationship between the personality dimensions and age, sex, number of companions, predator exposure, or owner experience. Although there remain important issues to be answered by future research, such as whether there is interobserver agreement in personality ratings and the extent to which the personality ratings are repeatable over time, the present study indicates that questionnaires of caregivers could in future provide a valuable tool to assess personality in rats.