Dominance hierarchy
Introduction
A dominance hierarchy is a type of social structure that arises when members of a social group interact, often aggressively, to create a ranking system. In social living groups, members are likely to compete for access to limited resources and mating opportunities. Rather than fighting each time they meet, relative relationships are formed between members of the same sex. This happens in a hierarchical manner where some individuals dominate others, hence the term dominance hierarchy.
Formation of Dominance Hierarchies
Dominance hierarchies can be formed by various behaviors, but they are most commonly established through physical confrontations and displays of power. These interactions may involve a variety of aggressive behaviors, such as biting, chasing, and posturing. The individual that consistently wins these interactions is considered the dominant individual, while the one that loses is considered subordinate.
The formation of dominance hierarchies is influenced by a variety of factors, including the size and strength of the individuals involved, their age and sex, and their prior social experiences. For example, in many animal species, larger and stronger individuals are more likely to become dominant. Similarly, in many human societies, older individuals or those with more social experience may have a higher social status.
Types of Dominance Hierarchies
There are several types of dominance hierarchies observed in nature, including linear hierarchies, despotic hierarchies, and circular hierarchies.
Linear Hierarchies
In a linear hierarchy, also known as a pecking order, each individual dominates the individuals ranked below it and is dominated by those ranked above it. This type of hierarchy is common in many bird species, where the dominant individual (often the largest or most aggressive) is at the top of the hierarchy, and each subsequent individual is dominated by all those above it.
Despotic Hierarchies
In a despotic hierarchy, one individual is dominant over all others. This individual has priority access to all resources and mates. This type of hierarchy is common in primate groups, where the dominant individual (often the largest or most aggressive male) has exclusive mating rights with the females in the group.
Circular Hierarchies
In a circular hierarchy, also known as a dominance loop, each individual is dominated by one other individual but dominates another, creating a circular relationship. This type of hierarchy is less common but has been observed in some species of fish and birds.
Benefits and Costs of Dominance Hierarchies
Dominance hierarchies have both benefits and costs for the individuals involved. The benefits of being a dominant individual often include priority access to resources and mates, while the costs may include the energy and risk involved in maintaining dominance.
Benefits
Dominant individuals often have priority access to resources, such as food and shelter. This can increase their survival and reproductive success. Dominant individuals also often have priority access to mates, which can increase their reproductive success. In some species, dominant individuals may also receive social benefits, such as support from subordinates in conflicts with outsiders.
Costs
However, being a dominant individual also has costs. Maintaining dominance often involves aggressive interactions, which can be energetically costly and carry the risk of injury. Dominant individuals may also be more visible to predators or targeted by rivals. In some species, dominant individuals may also bear costs associated with leadership, such as the responsibility of making decisions for the group or defending the group from threats.
Dominance Hierarchies in Different Species
Dominance hierarchies are found in a wide range of species, from insects to primates, and each species may have its unique characteristics and dynamics.
In Birds
In many bird species, dominance hierarchies are established through physical confrontations and displays of power. The dominant individual often has priority access to food and mates. For example, in chickens, the dominant rooster has exclusive mating rights with the hens in the flock.
In Mammals
In many mammal species, dominance hierarchies are established through physical confrontations and displays of power. The dominant individual often has priority access to food and mates. For example, in wolf packs, the dominant male and female (known as the alpha male and alpha female) have exclusive mating rights.
In Insects
In many insect species, dominance hierarchies are established through physical confrontations and displays of power. The dominant individual often has priority access to food and mates. For example, in honey bee colonies, the queen bee is the dominant individual and has exclusive reproductive rights.
Dominance Hierarchies in Humans
Dominance hierarchies also exist in human societies, although they are often more complex and less overt than in other species. Human dominance hierarchies can be based on a variety of factors, including physical strength, social status, wealth, and power.
In many traditional societies, older individuals or those with more social experience may have a higher social status. In modern societies, wealth and power are often associated with dominance. However, human dominance hierarchies can also be influenced by social norms, cultural values, and laws.