Experimental investigations of social behaviour in animals: Competitive orders as measures of social dominance

Abstract

Competitive orders are now in common usage as measures of social dominance in laboratory studies. Their use in this capacity is based on the premise that since dominance governs all priorities to resources within a group it is irrelevant as to which of these is chosen as its index. As a result methodological aspects of competitive measures have been neglected and most studies finding reliable orders on competitive tasks have reported these as being dominance orders; often without presenting social validations. The validity of the competitive measure is, therefore, clearly based on the assumption that dominance can be regarded as a unidimensional concept. But many of those laboratory studies which have presented relationships between aggressive and competitive orders or have used more than one competitive test have found evidence that this is not the case. This thesis investigates the validity of competitive measures of dominance in three species: the New Zealand ferret, the laboratory rat, and the domestic fowl. In general it is found that competitive orders for both ferrets and rats should not be regarded as measures of social dominance. Further work is required on the analysis of the competitive behaviour of the fowl before the concept of dominance can be meaningfully applied to the competitive behaviour of this species. The general problems of the validation of competitive orders and the use of the concept of social dominance are discussed.