INDIVIDUAL-DIFFERENCES IN TEMPERAMENT OF DOMESTIC-ANIMALS - A REVIEW OF METHODOLOGY

Individual differences in behaviour may be examined at two levels. First, individuals may differ in terms of frequencies, durations and/or patterning of particular measures of their behaviour. Second, individuals may differ in their temperament, ie in the may they react to environmental change and challenge. Individual differences in temperament are particularly relevant to animal welfare studies, for the welfare of an individual largely depends on whether it can cope with environmental challenge. Whereas the study of individual differences in behaviour at the first level may be achieved by using standard behavioural methods, the study of individual differences in temperament requires the use of more unusual methods, namely observers' ratings and behavioural tests. Observers' ratings provide information on subtle aspects of an individual's behaviour that could otherwise be overlooked. Behavioural tests facilitate comparisons between individuals in a more standardized way. It is suggested that both systems should be used together. Taking individual differences into account when designing experiments may help reduce variability in studies on welfare issues and understanding the causes of individual differences in temperament may allow us to reduce the incidence of some welfare problems.