Domination hierarchy

Dominance hierarchy is an ordering of individuals that can emerge from repeated contests, remembered outcomes, and submission to likely winners. The concept explains how fighting may decline once rank becomes established, while cautioning against treating a group-level pattern as though it were itself an adaptation selected for the good of the group.## Formation Through Repeated Contests In crickets, memory of past fights is general rather than tied to particular opponents. A cricket that has recently won repeatedly becomes more likely to adopt Hawk-like behavior; one on a losing streak becomes more Dove-like. In an experiment by R. D. Alexander, a model cricket was used to beat real crickets, after which the real ones were more likely to lose fights against other real crickets. The result illustrates how an individual’s recent record can alter its subsequent behavior even when it does not identify the opponent responsible for that record.

When crickets with this kind of general memory remain together in a closed group, the contests can sort them into a rank order. Individuals lower in the order tend to yield to those above them. No recognition of individuals is required: individuals accustomed to winning become more likely to win again, while those accustomed to losing become more likely to lose. Even if the first outcomes were random, repeated contests can therefore consolidate an ordered pattern. As the order takes shape, the number of serious fights tends to diminish.

The account calls this a kind of dominance hierarchy because some biologists reserve the term for cases involving recognition of particular individuals. The distinction matters: a cricket’s response can reflect its general history of winning or losing, whereas a recognized opponent carries a specific history. Dominance is not one single mechanism, but a visible social ordering that can arise through different kinds of memory and contest.

Recognition, Submission, and Group Effects

Hens and monkeys recognize individuals, so their memory of contests is specific. A monkey is more likely to lose to one that has beaten it before; the advantageous response is to be relatively Dove-like toward that particular opponent. When unfamiliar hens are introduced to one another, fighting is initially frequent. Over time, each hen learns her place in relation to each of the others, and fighting declines. This is not the same process as in crickets, where a generalized run of wins or losses can shift behavior without recognition of individual opponents.

Established groups of hens, in which fierce fighting is rare, have been observed to produce more eggs than groups whose membership changes continually and whose members consequently fight more often. The comparison links stability of membership and reduced fighting with higher egg production. It does not, however, establish that the hierarchy exists for the group’s benefit. The text cautions that describing the evolutionary function of a dominance hierarchy as the reduction of aggression confuses a group property with the individual behavior patterns that produce it. Those patterns are better considered in terms of evolutionarily stable strategies in asymmetric contests involving recognition and memory.

Rank can also affect access to reproduction. In the account of Wynne-Edwards’s interpretation, high-ranking individuals are more likely to breed, because females may prefer them or because they can prevent lower-ranking males from approaching females. Status thus acts like an entitlement to reproduce: rather than continually contesting females directly, individuals compete over social position, and lower-ranking males may submit. The proposed consequence is that status contests could limit population growth, but this is presented as Wynne-Edwards’s group-regulation interpretation, not as proof that the hierarchy evolved to regulate population size.

Rank, Resources, and Evolutionary Interpretation

Wynne-Edwards also interprets territorial competition as a system of breeding licences. If the population exceeds the number of available territories, some individuals fail to obtain territories and therefore do not breed. In red grouse, individuals who fail to win a territory can appear to give up further attempts and leave territory-holders undisturbed during the breeding season. The apparent restraint resembles acceptance of a rule that only those with a territory may reproduce. Together with rank-based access to mates, this interpretation casts formal contests over territory and social status as ways populations might remain below the level at which starvation takes its toll.

The account also describes ordinary rank relations as imperfect and changeable rather than absolute. In a peck order, individuals generally submit to those they know are likely to beat them, reducing prolonged fights and serious injuries; nevertheless, earnest contests occur, and an individual may rise above a former immediate superior. Rank is sustained by patterns of likely outcomes, not by an unbreakable rule that nobody can challenge.

The crucial analytical distinction is between the order observed at group level and the behavior selected through its effects on individuals. A hierarchy may accompany less aggression or higher egg production, yet those consequences do not make the hierarchy itself an agent with an evolutionary purpose. The explanatory focus remains on how individuals use memory, adjust their responses, and fare in asymmetric contests. This preserves the concept’s usefulness without turning a consequence of repeated individual interactions into an unsupported claim of group design.