Have you ever witnessed someone in a rage? It was probably a scary experience. People experiencing fierce anger may turn red in the face, scream or shout, throw things, say mean things, or hurt others. Not all aggression happens during a rage, but it is one common cause of it. So, what comprises aggression? How does aggression manifest? And what theories explore the origins of aggression?
- We are going to explore aggression. First, we will look at aggression in psychology.
- Then we will briefly discuss the different types of aggression.
- After, we will explore the causes of aggression, including hormonal mechanisms, genetics, and ethological and evolutionary explanations.
- Next, we will examine the social learning theory of aggression, including media influence on aggression.
- Finally, we briefly look at the frustration-aggression theory.
Aggression: Psychology
Aggression in psychology refers to behaviours that could harm yourself and others or could affect objects in the environment. This harm can be physical or psychological.
Aggression includes harming others or destroying the environment, such as breaking a door by punching it or throwing something.
How do we, then, measure aggression in psychology? This can be done in several ways, mainly by counting how many times a person is aggressive in response to a stimulus or trigger and the intensity of the aggression on a scale/ratio.
It is important to understand where aggression stems from and why it occurs, as, according to the World Health Organisation, in 2002, almost twice as many people died from interpersonal altercations than from being victims of war (World Health Organization & Krug, E., 2002, as cited in Popova, 2008).
Types of Aggression
What kind of behaviour do scientists count as aggressive? There are a few ways aggression can be observed to be studied. To generalise, there are three types of aggression:
- Reactive-expressive (being verbally and physically aggressive).
- Reactive-inexpressive (being hostile and displaying antipathy).
- Proactive-relational aggression (being vicious towards others, impacting relationships).
Several theories on the types of aggression causes are explored using biological, social and psychological explanations.
Causes of Aggression in Psychology
According to psychology, potential reasons implicated in the causes of aggression include neuronal and hormonal mechanisms, genetic, ethological, and evolutionary explanations, and social learning theory explanations. Psychology also explores the influence of institutions on aggression and media influences.
Neural and Hormonal Mechanisms
Here, we consider the limbic system and the effects serotonin, testosterone, and cortisol have on aggression.
The Limbic System
The limbic system plays an important role in regulating emotional behaviours and includes structures such as the hypothalamus, the hippocampus, and the amygdala. The amygdala is particularly important in aggression. When stimulated in animal studies, animals show more aggressive behaviours. When removed, however, they showed less or no aggressive behaviours.
Fig. 1 - The limbic system comprises the amygdala, the hippocampus, and other notable structures.¹
Serotonin Research
Serotonin is a neurotransmitter. It has widespread inhibitory effects on the brain. When considering aggression, normal serotonin levels in the orbitofrontal cortex (OFC) correlate with greater self-control (inhibiting impulsive behaviour). Decreased levels of serotonin reduce self-control and may increase impulsivity.
This is the serotonin deficiency hypothesis: decreased serotonin levels cause a reduced inhibitory effect, affecting the OFC and causing more impulsive and aggressive behaviours.
Testosterone and Cortisol Research
Testosterone is an androgen, a hormone controlling the development of male characteristics. It is produced in the gonads (male testes and female ovaries) and the adrenal cortex. It is suggested that testosterone is linked to aggression due to the correlation between men having higher testosterone levels and committing more aggressive acts than women.
Cortisol is a stress hormone. Nearly every cell in the body has receptors for cortisol, so its effects vary. Usually, it aids in the body’s response to chronic stress, affecting the immune system, muscles, and so on. The Fearlessness Theory suggests stress induced by cortisol can inhibit aggression through fear.
Overall, the link between neural and hormonal mechanisms and aggression is correlational, not causal. It’s not completely clear whether hormones affect aggression, or if aggression causes stimulation in hormone production.
Genetic, Ethological, and Evolutionary Explanations
Aggression is affected by hormones and neurotransmitters. So, where genetics are concerned, genes play an important role in affecting the production of these components, which, in turn, affects aggression.
Genetic Explanations for Aggression
According to Popova (2008), behaviours such as attacking, defending, and other aggressive traits that apply to animals and humans are specifically related to serotonin as it modulates these behaviours. Namely, the functioning of a serotonin system relies on:
- Synthesis (making) and appropriate degradation (scrubbing away) of serotonin. Serotonin uptake.
- Serotonin 5-HT receptors/degradation.
- Genes such as the PET-1 gene (covered in more detail elsewhere).
Monoamine oxidase A (MAOA; the warrior gene) gained notoriety in a 2006 study by Dr Rod Lea on New Zealand Māori men. It was suggested that those with the warrior gene exhibit higher levels of aggressive behaviours in response to provocation.
The MAOA gene codes for the production of the enzyme involved in breaking down neurotransmitters in the synapses between neurones. This is especially true for serotonin. When variants of this gene occur, it can result in lower enzyme production, causing neurotransmitters to remain in the synapse for longer, resulting in brain and behaviour dysfunction.
The warrior gene has been highly criticised for its unethical phrasing.
Gender and Aggression
Considering the association certain hormones have on aggression, Gender may play a role in aggressive behaviour tendencies. The super-male hypothesis, established by Sandberg (1961) suggests the mutation of the XYY chromosome in males would lead to more aggression. Multiple studies indicate that gender does have some role in aggression.
Rissman et al. (2006) found the Sry gene was associated with high levels of aggression in mice. This gene leads to the development of the gonads and high androgen levels in males. Lagerspetz et al. (1992) found that girls tended to be indirectly aggressive, and boys were equally as indirectly aggressive but more directly aggressive.
Fig. 2 - Aggression can come down to a person's DNA.
Ethological Explanations of Aggression
Aggression can be studied and explained by analysing non-human animal behaviours and comparing them to humans. This kind of study is known as ethology.
Konrad Lorenz suggested that aggression in animals is innate, an instinctual process to help species maximise their resources (food, space, and other necessities). Fights within species occur till one backs down, not to death, to avoid killing off their own species. This is why some animals growl or snarl as a warning first, known as an innate releasing mechanism (IRM).
Innate releasing mechanisms (IRMs) are where animals have evolved to have a specific response to certain stimuli.
IRMs lead to Fixed Action Patterns (FAPs), which are an ethological term used to describe instinctive behaviours in a species, usually an action in response to a stressor.
The animals have a fixed action pattern when faced with a particular releasor. In effect, an IRM is where a neural sensorimotor interface links and creates a response between a stimulus and the fixed action pattern (Ewert, 2013). Once the IRM occurs, the FAP will occur after and cannot be stopped.
The hydraulic model of instinctive behaviour suggested by Lorenz states that all animals create a reservoir of pent-up energy, known as Action Specific Energy. IRMs trigger FAPs, which release this energy, and as a result, aggression levels lower until this reservoir is filled up again.
Lorenz claims that this reservoir builds up in humans because present-day man cannot discharge his aggression.
Evolutionary Explanations of Aggression
Evolutionary explanations of aggression cite natural selection as a large part of why aggression has developed the way it has in humans. Therefore, aggression is an adaptive response that serves a purpose in both survival and reproduction. If an animal's last piece of meat is being fought for by a competing animal, an aggressive act to secure it will increase each animal’s chance of survival if they choose to fight for it and win.
Inter-group aggression is where aggression occurs between two groups of the same species, known as 'ingroup' and ‘outgroup’ based on where the individuals identify themselves.
It is essentially us vs them.
For example, a pride of lions sees another pride of lions, or in gangs in human behaviours.
The behaviour the outgroup exhibits is undesirable to the ingroup.
Intra-group aggression occurs when members of an ingroup show aggression toward each other, usually forming due to jealousy/rivalry; for instance, in a group of competing males, the need to be the sexually dominant one.
Social Learning Theory of Aggression
Social-psychological explanation of aggression includes social learning theory, including reference to Bandura's study, the Bobo Doll Experiment, deindividuation and the influence of media. Social-psychological explanations of aggression suggest children learn by observing others.
Bandura and the Bobo Doll Experiment
The social learning theory of aggression claims aggression is learned through observation, imitation, and reinforcement (positive or negative, direct or vicarious). The Bobo Doll experiment supported Bandura’s claims, showing that children can learn behaviours through observation alone.
In this experiment, in contrast to the control group, the children exposed to aggressive behaviours tended to exhibit aggressive behaviours themselves as a result.
The deindividuation theory, proposed by Festinger et al. (1952), states that if humans believe they can get away with doing aggressive behaviours, they will do so. Anonymity will increase this phenomenon. The contagion theory is suggested to be the start of deindividuation.
You can read about Bandura's Bobo Doll Experiment in other StudySmarter articles!
Institutional Theories of Aggression in the Context of Prisons
Institutional theories of aggression in the context of prisons involve the situational approach and the dispositional approach.
The situational approach (Sykes, 1958) is that prisons make people more aggressive due to the deprivation of their liberties, rather than the prisoners being at that level of aggression before sentencing (the pains of imprisonment). This is where the manifestation of aggression is placed on the institution and organisation, focused on the hierarchy in place.
The environment is the cause, in a sense.
Milgram believed people were loyal to such hierarchies and would obey if necessary. Similar to this is the Stanford Prison Experiment, where Zimbardo (1971) found that those who were given the authoritative title of ‘Prison Guard’ became more aggressive towards those given the title of ‘Prisoner’, despite neither side earning the title officially.
This is a dysfunctional power system in an institution inducing aggression in people.
The dispositional approach uses the importation model and focuses on the behaviour and beliefs of prisoners before they enter prison. Irwin and Cressey (1962) argued that prisoners were often violent and aggressive before prison and, therefore, naturally inclined to behave this way inside prison.
A prison is an aggressive place because the people there are aggressive.
Fig. 3 - Aggression was high in the Stanford Prisoner Experiment.
Media Influences on Aggression
Media use has risen considerably in recent years. As a result, some have hypothesised that this increase has caused issues with aggression. The blame for aggression has often been pinned on different media sources. The common trend today is to target computer games that use violence.
Different theories support and disprove this idea. Learning Theories are referenced (i.e., Skinner, Anderson and Drill, Bandura), alongside the general aggression model and the neurological effects of media influences on aggression.
Media influences consider:
Each suggests that prolonged exposure to violent media influences people's reactions to feeling angry and seeing aggressive behaviour in real life, normalising aggression.
Frustration-Aggression Theory
The frustration-aggression theory states that frustration leads to aggressive behaviours resulting from an inability to do a certain action or reach a certain goal. Due to this, a need to release this energy occurs and the frustration is released as aggression, sometimes to a source that isn’t the main cause of the frustration.
How does one reduce aggression in psychology? Reducing aggression involves a person understanding the causes of their aggression and learning new responses and appropriate behaviours rather than allowing the frustration to build and then explode into aggression.
Therapies, talking it out, and self-control will help reduce aggression.
Aggression - Key takeaways
- Aggression in psychology refers to behaviours that could harm yourself or others or could affect objects in the environment.
- Genetics considers the role of neurotransmitters, hormones, and the warrior gene.
- Social-psychological explanations consider social learning theories and the frustration-aggression theory.
- Institutional theories consider the situational approach and the dysfunctional approach, as well as the importation model.
- Media influences in aggression include computer games, cognitive priming, desensitisation, and disinhibition.
References
- Fig. 1 - 1511 The Limbic Lobe-vi (https://commons.wikimedia.org/wiki/File:1511_The_Limbic_Lobe-vi.jpg) by OpenStax College (https://openstax.org/books/anatomy-and-physiology/pages/1-introduction) is licensed by CC BY 3.0 (https://creativecommons.org/licenses/by/3.0/deed.en)
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