Social defeat

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In social psychology, social defeat is the negative experience of being excluded from the majority group. The term is used in the study of the physiological and behavioral effects of hostile interactions among either animals or humans, in either a dyadic or in a group-individual context, potentially greatly affecting control over resources, access to mates, and social positions.

Background

Research on social stress has accumulated a useful body of knowledge, providing perspective on the effects of detrimental social and environmental interaction on the brain. Research and experimentation suffer from many methodological difficulties: usually a lack of ecological validity (similarity with natural conditions and stressors) or are not amenable to scientific investigation (difficult to test and verify).

Social psychology approaches to human aggression have developed a multitude of perspectives, based on observations of human phenomena like bullying, physical and verbal abuse, relational and indirect aggression, etc. Despite the richness of theories developed, the body of knowledge generated has not satisfied scientific requirements of testability and verifiability.

Animal studies of within-species aggression developed in 2 main branches: A) approaches based on laboratory experiments, on controlled conditions, allowing the measurement of behavioral,

neurological
variables, but with the shortcoming of applying unnatural stressors (such as foot-shocks and restraint stress) in unnatural conditions (laboratory cages rarely approximate native habitats); B) approaches based on observations of animals in naturalistic settings, which avoided artificial environments and unnatural stresses, but usually not allowing the measurement of physiological effects or the manipulation of relevant variables.

In real life situations, animals (including humans) have to cope with

social positions
(Bjorkqvist, 2001; Rohde, 2001; Allen & Badcock, 2003).

Social defeat is a source of chronic

stress in animals and humans, capable of causing significant changes in behaviour, brain functioning, physiology, neurotransmitter and hormone levels, and health
(Bjorkqvist, 2001; Rohde, 2001; Allen & Badcock, 2003).

History

The social defeat approach was originated from animal experiments, using the "resident-intruder" paradigm, in which an animal was placed in the cage of another animal or group of animals of the same species, in a manner that allowed a non-lethal conflict. It has been documented to produce anxiety-like and depressive-like behavioral declines in susceptible mice, for instance.[1]

If animals are allowed to fight on a single occasion only, it is usually regarded as a model of acute stress; if they are allowed to fight on several occasions, on different days, consecutive or not, it is regarded as a model of chronic stress. After the defeat or in the interval between fights, the subordinate animal may also be exposed to threats from the dominant one, by having to stay in a cage or compartment beside or nearby the dominant, exposed to its visual or olfactory cues.

Later, the social defeat approach was also applied to observations of animal within-species aggression, in the wild, which suggested that the hypotheses generated on artificial laboratory settings can also be applied in observed in natural settings, confirming the predictions of the model.

In humans

It has been proposed that animal models of social conflict may be useful for studying a number of

eating disorders and schizophrenia
(Bjorkqvist, 2001; Selten & Cantor-Graae, 2005; Rohde, 2001).

The social defeat model has been extended to include observations of human

social psychology
study of aggression, in which comparisons are drawn exclusively from experiments involving humans (Bjorkqvist, 2001; Rohde, 2001).

Bullying has interesting parallels with animal models of social defeat, the bully being equivalent to the dominant animal and the victim the subordinate one. At stake are possessions of material objects, money, etc., social position in the group, represented by in-group prestige, and the consequent lack of access to mates, including for socio-sexual behaviors like copulation. Human victims typically experience symptoms like low self-esteem (due to low regard by the group), feelings of depression (due to unworthiness of efforts), social withdrawal (reduced investments in the social environment), anxiety (due to a threatening environment), and they can also be shown to experience a plethora of physiological effects, e.g. increased corticosterone levels, and also a shift towards sympathetic balance in the autonomic nervous system (Bjorkqvist, 2001).

Research about human aggression, usually conducted by psychologists or social psychologists, resembles to a great extent the research about social defeat and animal aggression, usually conducted by biologists or physiological psychologists. However, there is the problem of the use of different terminologies for similar concepts, which hinders communication between the two bodies of knowledge (Bjorkqvist, 2001).

Similarly, research on depression has employed similar constructs, such as learned helplessness, although that theory is focused on the perceived inability to escape any sort of negative stimuli rather than on social factors.

Behavioral and physiological effects