Dominance (ethology)

Dominance in ethology is an "individual's preferential access to resources over another." Dominance in the context of biology and anthropology is the state of having high social status relative to one or more other individuals, who react submissively to dominant individuals. This enables the dominant individual to obtain access to resources such as food or potential mates at the expense of the submissive individual, without active aggression. The absence or reduction of aggression means unnecessary energy expenditure and the risk of injury are reduced for both. The opposite of dominance is submissiveness.

Dominance may be a purely dyadic relationship, i.e. individual A is dominant over individual B, but this has no implications for whether either of these is dominant over a third individual C. Alternatively, dominance may be hierarchical, with a transitive relationship, so that if A dominates B and B dominates C, A always dominates C. This is called a linear dominance hierarchy. Some animal societies have despots, i.e. a single dominant individual with little or no hierarchical structure amongst the rest of the group. Horses use coalitions so that affiliated pairs in a herd have an accumulative dominance to displace a third horse that normally out-ranks both of them on an individual basis.

Dominance may initially be established by fighting, or simply by threatening displays or interchanges. Once established, however, dominance is usually maintained by agonistic (competitive) behaviours with aggression considerably reduced or sometimes absent. In the maintenance of dominance relationships, the behaviour of the sub-dominant animal is critical. If a dominant animal perceives its status is being threatened, it will likely threaten the sub-dominant individual. The sub-dominant must then either escalate the intensity of the interaction to challenge the dominant, or defer. In this way, it is often the behaviour of the sub-dominant animal that maintains the dominance relationship, rather than the dominant.

The ultimate function of a dominance hierarchy is to increase the individual or inclusive fitness of the animals involved in its formation. Fighting to acquire resources such as food and mates is expensive in terms of time, energy and the risk of injury. By developing a dominance hierarchy, animals determine which individuals will get priority of access to resources, particularly when they are limited; there is a reduction in aggression once a pecking order has been developed. Therefore, the proximate functions of a pecking order are to reduce the costs of time, energy and risk of injury incurred during resource acquisition and defense.

...
Wikipedia