Social defeat
Encyclopedia
Social defeat refers to losing a confrontation among conspecific
animals, or any kind of hostile dispute among humans, in either a dyadic or in a group-individual context, generating very significant consequences in terms of control over resources, access to mates and social positions.
has developed a variety of different approaches, developing a wealthy body of literature, providing a richness of perspectives. However, most of the theories developed have either a lack of ecological validity (similarity with natural conditions and stressors) or are not amenable to scientific investigation (difficult to test and verify).
On the one side, social psychological approaches to human aggression
have developed a multitude of perspectives, based on observations of human phenomena like bullying, mobbing, physical and verbal abuse, relational and indirect aggression, etc. Despite the richness of theories developed, the body of knowledge generated have not satisfied scientific requirements of testability
and verifiability
.
By the other side, 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, endocrine and neurological variables, but with the shortcoming of applying unnatural stressors (like food-shocks, confinement stress, etc) in unnatural conditions (the cage, a poor artificial environment); 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 (as well as humans) have to cope with stresses generated within their own species, during their interactions with conspecifics, especially due to recurrent struggles over the control of limited resources, mates and 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).
, 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.
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 different 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.
The social defeat model has been extended to include observations of human aggression
, bullying, relational aggression
, chronic subordination and humiliation
. The social defeat model attempts to extend animal studies to include human behaviour as well, in contrast to the 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).
and can lead to a variety of behavioral effects, like social withdrawal (reduced interactions with conspecifics), lethargy (reduced locomotor activity), reduced exploratory behavior (of both open field and novel objects), anhedonia (reduced reward-related behaviors), decreased socio-sexual behaviors (including decreased attempts to mate and copulate after defeat), various motivational deficits, decreased levels of testosterone (due to a decline in the functionality of the Laydig cells of the testes), increased tendencies to stereotyped behaviours and self-administration of drugs and alcohol
(Rygula et alli, 2005; Huhman, 2006).
Research also implicates that the referred behavioral effects are moderated by neuroendocrine phenomena involving serotonin
, dopamine
, epinephrine
, norepinephrine
, and in the hypothalamic-pituitary-adrenal axis
, locus ceruleus
and limbic system
s (Bjorkqvist, 2001; Rygula et alli, 2005; Selten & Cantor-Graae, 2005; Marinia et alli, 2006; Huhman, 2006).
Both animal and human studies suggest that the social environment has a strong influence on the consequences of stresses. This finding seems to be especially true in the case of social stresses, like social defeat (Bjorkqvist, 2001; Rygula et alli, 2005; de Jong et alli, 2005).
In animal studies, animals housed collectively showed reduced symptoms after defeat, in comparison with those housed alone; and animals that live in more stable groups (with stable hierarchies, less intra-group aggression) exhibit reduced effects after a defeat, in comparison with those housed in a more unstable group (de Jong et alli, 2005).
In human studies, individuals with greater support seem to be protected against excessive neuroendocrine activation, thereby reducing the adverse effects of stresses in general, and especially stresses of social origin.
This apparent confusion, in which social defeat generates behavioral and neuroendocrine effects, both of which depending on social contextual variables, raises the question of how to interpret this data. A useful concept is the concept of “causal chain”, in which recurrent evolutionary events, in this case intra-specific competition, generates selective pressures
that last for thousands of generations, influencing a whole species. This way physiological phenomena may evolve, in this case the referred neuro-endocrine phenomena, to facilitate adaptive patterns of action by individuals, in this case the referred behavioral effects. According to this framework, selective pressures generated by intra-specific competition can be considered as the ultimate cause, the neuroendocrine phenomena can be considered to be the proximate causes (sometimes also called mechanisms or moderators) and the observed behavioral alterations are considered the effects (the end events in the causal chain)(Gilbert et alli, 2002; Allen & Badcock, 2003; Rygula et alli, 2005).
Some authors, for example Randolph Nesse, warn us that patterns of behavior commonly considered inappropriate or even pathological may well have adaptive value. According to this view, several authors propose that behaviors considered abnormal may be in fact part of an adaptive response to stresses experienced in modern or at least in old environments, for example social stress from chronic subordination or interpersonal conflicts (Gilbert et alli, 2002; Allen & Badcock, 2003).
Conspecificity
Conspecificity is a concept in biology. Two or more individual organisms, populations, or taxa are conspecific if they belong to the same species....
animals, or any kind of hostile dispute among humans, in either a dyadic or in a group-individual context, generating very significant consequences in terms of control over resources, access to mates and social positions.
Background
Research on social stressSocial stress
Social Stress is stress that stems from one’s relationships with others and from his or her social environment. A person experiences stress when he or she does not have the ability or resources to cope when confronted with an external stimulus . When confronted with a stressor, people assess...
has developed a variety of different approaches, developing a wealthy body of literature, providing a richness of perspectives. However, most of the theories developed have either a lack of ecological validity (similarity with natural conditions and stressors) or are not amenable to scientific investigation (difficult to test and verify).
On the one side, social psychological approaches to human aggression
Aggression
In psychology, as well as other social and behavioral sciences, aggression refers to behavior between members of the same species that is intended to cause humiliation, pain, or harm. Ferguson and Beaver defined aggressive behavior as "Behavior which is intended to increase the social dominance of...
have developed a multitude of perspectives, based on observations of human phenomena like bullying, mobbing, physical and verbal abuse, relational and indirect aggression, etc. Despite the richness of theories developed, the body of knowledge generated have not satisfied scientific requirements of testability
Testability
Testability, a property applying to an empirical hypothesis, involves two components: the logical property that is variously described as contingency, defeasibility, or falsifiability, which means that counterexamples to the hypothesis are logically possible, and the practical feasibility of...
and verifiability
Falsifiability
Falsifiability or refutability of an assertion, hypothesis or theory is the logical possibility that it can be contradicted by an observation or the outcome of a physical experiment...
.
By the other side, 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, endocrine and neurological variables, but with the shortcoming of applying unnatural stressors (like food-shocks, confinement stress, etc) in unnatural conditions (the cage, a poor artificial environment); 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 (as well as humans) have to cope with stresses generated within their own species, during their interactions with conspecifics, especially due to recurrent struggles over the control of limited resources, mates and social positions (Bjorkqvist, 2001; Rohde, 2001; Allen & Badcock, 2003).
Social defeat is a source of chronic stress
Stress (medicine)
Stress is a term in psychology and biology, borrowed from physics and engineering and first used in the biological context in the 1930s, which has in more recent decades become commonly used in popular parlance...
in animals and humans, capable of causing significant changes in behaviour, brain
Brain
The brain is the center of the nervous system in all vertebrate and most invertebrate animals—only a few primitive invertebrates such as sponges, jellyfish, sea squirts and starfishes do not have one. It is located in the head, usually close to primary sensory apparatus such as vision, hearing,...
functioning, physiology
Physiology
Physiology is the science of the function of living systems. This includes how organisms, organ systems, organs, cells, and bio-molecules carry out the chemical or physical functions that exist in a living system. The highest honor awarded in physiology is the Nobel Prize in Physiology or...
, neurotransmitter and hormone levels, and health
Health
Health is the level of functional or metabolic efficiency of a living being. In humans, it is the general condition of a person's mind, body and spirit, usually meaning to be free from illness, injury or pain...
(Bjorkqvist, 2001; Rohde, 2001; Allen & Badcock, 2003).
History
The social defeat approach was originated from animal experiments, using the "resident-intruder" paradigmParadigm
The word paradigm has been used in science to describe distinct concepts. It comes from Greek "παράδειγμα" , "pattern, example, sample" from the verb "παραδείκνυμι" , "exhibit, represent, expose" and that from "παρά" , "beside, beyond" + "δείκνυμι" , "to show, to point out".The original Greek...
, 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.
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 different 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 psychiatric disorders, including major depression, generalized anxiety, post-traumatic stress disorder, drug abuse, aggressive psychopathologies, eating disorders and even schizophrenia (Bjorkqvist, 2001; Selten & Cantor-Graae, 2005; Rohde, 2001).The social defeat model has been extended to include observations of human aggression
Aggression
In psychology, as well as other social and behavioral sciences, aggression refers to behavior between members of the same species that is intended to cause humiliation, pain, or harm. Ferguson and Beaver defined aggressive behavior as "Behavior which is intended to increase the social dominance of...
, bullying, relational aggression
Relational aggression
Relational aggression, also known as covert aggression or covert bullying, is a type of aggression in which harm is caused through damage to relationships or social status within a group rather than by means of actual or threatened physical violence...
, chronic subordination and humiliation
Humiliation
Humiliation is the abasement of pride, which creates mortification or leads to a state of being humbled or reduced to lowliness or submission. It can be brought about through bullying, intimidation, physical or mental mistreatment or trickery, or by embarrassment if a person is revealed to have...
. The social defeat model attempts to extend animal studies to include human behaviour as well, in contrast to the 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).
Behavioral and Physiological effects
Social defeat is a very potent stressorStress (medicine)
Stress is a term in psychology and biology, borrowed from physics and engineering and first used in the biological context in the 1930s, which has in more recent decades become commonly used in popular parlance...
and can lead to a variety of behavioral effects, like social withdrawal (reduced interactions with conspecifics), lethargy (reduced locomotor activity), reduced exploratory behavior (of both open field and novel objects), anhedonia (reduced reward-related behaviors), decreased socio-sexual behaviors (including decreased attempts to mate and copulate after defeat), various motivational deficits, decreased levels of testosterone (due to a decline in the functionality of the Laydig cells of the testes), increased tendencies to stereotyped behaviours and self-administration of drugs and alcohol
Self Medication
Self Medication is an album by the New York City ska band The Slackers. It was released on Indication Records in 2008 .-Track listing:# "Every Day Is Sunday" – 2:35# "Don't You Want a Man" – 3:30...
(Rygula et alli, 2005; Huhman, 2006).
Research also implicates that the referred behavioral effects are moderated by neuroendocrine phenomena involving serotonin
Serotonin
Serotonin or 5-hydroxytryptamine is a monoamine neurotransmitter. Biochemically derived from tryptophan, serotonin is primarily found in the gastrointestinal tract, platelets, and in the central nervous system of animals including humans...
, dopamine
Dopamine
Dopamine is a catecholamine neurotransmitter present in a wide variety of animals, including both vertebrates and invertebrates. In the brain, this substituted phenethylamine functions as a neurotransmitter, activating the five known types of dopamine receptors—D1, D2, D3, D4, and D5—and their...
, epinephrine
Epinephrine
Epinephrine is a hormone and a neurotransmitter. It increases heart rate, constricts blood vessels, dilates air passages and participates in the fight-or-flight response of the sympathetic nervous system. In chemical terms, adrenaline is one of a group of monoamines called the catecholamines...
, norepinephrine
Norepinephrine
Norepinephrine is the US name for noradrenaline , a catecholamine with multiple roles including as a hormone and a neurotransmitter...
, and in the hypothalamic-pituitary-adrenal axis
Hypothalamic-pituitary-adrenal axis
The hypothalamic-pituitary-adrenal axis , also known as thelimbic-hypothalamic-pituitary-adrenal axis and, occasionally, as the hypothalamic-pituitary-adrenal-gonadotropic axis, is a complex set of direct influences and feedback interactions among the hypothalamus, the pituitary gland ,...
, locus ceruleus
Locus ceruleus
The locus coeruleus , is a nucleus in the brainstem involved with physiological responses to stress and panic. It was discovered in the 18th century by Félix Vicq-d'Azyr....
and limbic system
Limbic system
The limbic system is a set of brain structures including the hippocampus, amygdala, anterior thalamic nuclei, septum, limbic cortex and fornix, which seemingly support a variety of functions including emotion, behavior, long term memory, and olfaction. The term "limbic" comes from the Latin...
s (Bjorkqvist, 2001; Rygula et alli, 2005; Selten & Cantor-Graae, 2005; Marinia et alli, 2006; Huhman, 2006).
Both animal and human studies suggest that the social environment has a strong influence on the consequences of stresses. This finding seems to be especially true in the case of social stresses, like social defeat (Bjorkqvist, 2001; Rygula et alli, 2005; de Jong et alli, 2005).
In animal studies, animals housed collectively showed reduced symptoms after defeat, in comparison with those housed alone; and animals that live in more stable groups (with stable hierarchies, less intra-group aggression) exhibit reduced effects after a defeat, in comparison with those housed in a more unstable group (de Jong et alli, 2005).
In human studies, individuals with greater support seem to be protected against excessive neuroendocrine activation, thereby reducing the adverse effects of stresses in general, and especially stresses of social origin.
This apparent confusion, in which social defeat generates behavioral and neuroendocrine effects, both of which depending on social contextual variables, raises the question of how to interpret this data. A useful concept is the concept of “causal chain”, in which recurrent evolutionary events, in this case intra-specific competition, generates selective pressures
Evolutionary pressure
Any cause that reduces reproductive success in a proportion of a population, potentially exerts evolutionary pressure or selection pressure. With sufficient pressure, inherited traits that mitigate its effects - even if they would be deleterious in other circumstances - can become widely spread...
that last for thousands of generations, influencing a whole species. This way physiological phenomena may evolve, in this case the referred neuro-endocrine phenomena, to facilitate adaptive patterns of action by individuals, in this case the referred behavioral effects. According to this framework, selective pressures generated by intra-specific competition can be considered as the ultimate cause, the neuroendocrine phenomena can be considered to be the proximate causes (sometimes also called mechanisms or moderators) and the observed behavioral alterations are considered the effects (the end events in the causal chain)(Gilbert et alli, 2002; Allen & Badcock, 2003; Rygula et alli, 2005).
Some authors, for example Randolph Nesse, warn us that patterns of behavior commonly considered inappropriate or even pathological may well have adaptive value. According to this view, several authors propose that behaviors considered abnormal may be in fact part of an adaptive response to stresses experienced in modern or at least in old environments, for example social stress from chronic subordination or interpersonal conflicts (Gilbert et alli, 2002; Allen & Badcock, 2003).
See also
- Resource holding potentialResource holding potentialIn biology, resource holding potential is the ability of an animal to win an all-out fight if one were to take place.The term was coined by Geoff Parker to disambiguate physical fighting ability from the motivation to persevere in a fight . Originally the term used was 'Resource Holding Power',...
- DehumanizationDehumanizationDehumanization is to make somebody less human by taking away his or her individuality, the creative and interesting aspects of his or her personality, or his or her compassion and sensitivity towards others. Dehumanization may be directed by an organization or may be the composite of individual...
- HazingHazingHazing is a term used to describe various ritual and other activities involving harassment, abuse or humiliation used as a way of initiating a person into a group....
- Social rejectionSocial rejectionSocial rejection occurs when an individual is deliberately excluded from a social relationship or social interaction. The topic includes both interpersonal rejection and romantic rejection. A person can be rejected on an individual basis or by an entire group of people...
- Psychological traumaPsychological traumaPsychological trauma is a type of damage to the psyche that occurs as a result of a traumatic event...