Animal temperament and individual animal personalities in combination with an animal’s ability to cope with stressful situations have been studied in the past. There are clear differences between cattle breeds in urinary catecholamine concentration. Individual differences in behaviour exist in a large number of species and breeds within species. This review gives an overview of the involvement of catecholamines in the expression of stress in animals. Domestication, the heritability of stress and terms currently used in animal personality research are discussed. This includes animals used for production. The aim of this review is to consolidate and present current knowledge on the function of an activated catecholamine system and to question whether behavioural changes of animals are tending towards increased aggressiveness or towards improved coping mechanisms.