THE ETHOLOGICAL EXPLANATION OF AGGRESSION

SPECIFICATION: The ethological explanation of aggression, including reference to innate releasing mechanisms and fixed action patterns

KEY TERMS

ALTRICIAL SPECIES

Animals are born helpless and need much parental care before surviving independently. They usually have closed eyes, little fur or feathers, and weak muscles at birth. Examples include humans, puppies, and baby birds like robins.

APOSEMATIC

Bright colours or patterns on an animal warn predators that it is toxic or dangerous. For example, poison dart frogs have bright colours to signal their toxicity.

ASSOCIATIVE LEARNING

A type of learning where an animal links two things, such as a stimulus and a response. For example, Pavlov’s dogs learned to associate a bell with food, making them salivate when they heard the bell.

CRITICAL PERIOD

A short, specific time in development when behaviour must be learned, or it won’t develop properly. For example, baby birds must imprint on a caregiver shortly after hatching.

EUSOCIAL

A high level of social organization where individuals live in groups, divide labour and have cooperative care of the young. Bees, ants, and termites are examples of eusocial species.

ETHOLOGY

The scientific study of animal behaviour focuses on natural environments and instinctive actions. Ethologists study behaviours like imprinting, mating, and survival strategies in different species.

FILIAL ATTACHMENT

The strong bond that young animals form with their parents or caregivers shortly after birth. This helps ensure survival by keeping the young close to their caregivers for protection and learning.

FIXED ACTION PATTERNS (FAPs)

Innate, automatic behaviours triggered by a specific stimulus follow a set sequence. Once started, they continue to completion, even if the trigger is removed. For example, a goose rolling an egg back into its nest will complete the action even if it is taken away.

IMPRINTING

A rapid, irreversible form of learning that happens shortly after birth. Young animals attach to and follow the first moving object they see. Lorenz (1935) showed that geese imprinted on him as if he were the first thing they saw.

INNATE BEHAVIOUR

A behaviour an animal is born with rather than one it learns. Examples include fixed action patterns, imprinting, and social releasers. These behaviours have evolved because they help animals survive and reproduce.

INNATE RELEASING MECHANISMS (IRM)

A built-in system in the brain that detects a specific stimulus and triggers an instinctive response. For example, a baby’s cry (stimulus) triggers a mother’s caregiving response.

INSTINCT

It is an automatic, natural behaviour that happens without thinking or learning. Instincts are hardwired into an animal’s brain and help with survival. For example, newborn babies instinctively suckle for milk.

MONOTROPY

Bowlby’s idea is that babies form one special attachment (usually to their mother), which is more important than all other attachments. This bond shapes future relationships and emotional development.

PHYLOGENY

The evolutionary history of a species shows how it has changed over time and how it is related to other species. Scientists study phylogeny by looking at fossils and DNA.

PRECOCIAL SPECIES

Animals born in a more developed state can move, see, or feed themselves shortly after birth. They usually have open eyes, fur, or feathers and can follow their parents immediately. Examples include ducks, horses, and giraffes.

RELEASER; RELEASING MECHANISM (RM)

A specific stimulus that triggers an automatic response. For example, a mother bird feeding a chick is triggered by the chick’s open beak, which acts as a release.

RITUALISED AGGRESSION

SEXUAL IMPRINTING

When early attachment influences later mate preferences. Lorenz found that birds imprinted on humans sometimes preferred humans as mates, showing how early experiences shape attraction.

SOCIAL RELEASERS

Innate behaviours that encourage caregiving from parents. Human babies cry, smile, and cling to get attention and care. These behaviours help form attachments and ensure survival.

THE ETHOLOGICAL APPROACH

Ethology, the study of animal behaviour in natural settings, examines aggression as part of evolutionary processes. Ethologists explore aggression as an adaptive mechanism that helps animals secure resources, establish dominance, and ensure reproductive success.

In his influential book On Aggression, Konrad Lorenz (1966) argued that humans, like other animals, possess innate aggressive behaviours that have evolved to serve specific survival and reproductive functions. He suggested that human aggression is not merely a product of social or environmental influences but is deeply rooted in biological and evolutionary mechanisms.

Lorenz’s research falls within ethology, a branch of biology that studies behaviour in the natural environment. It focuses on innate, instinctive behaviours that have evolved through natural selection. According to Lorenz, aggression is a biological drive, much like hunger, thirst, and reproduction, and it is critical for the survival and reproductive success of individuals and species.

AGGRESSION BETWEEN SPECIES AND GROUPS

Aggression in animals occurs not only within a species but also between species.

PREDATION AND AGGRESSION

The relationship between predators and their prey is often viewed as interspecific aggression. However, whether predatory behaviour should be classified as actual aggression remains a debate among researchers.

Some ethnologists argue that predation fundamentally differs from aggression, as it is motivated by hunger and survival rather than hostility or dominance. Unlike conspecific (same-species) aggression, which is often accompanied by threat displays, intimidation, and ritualised behaviour, predatory behaviour lacks these social signals. For example, a cat hunting a rat does not exhibit aggressive posturing such as hissing or arched-back displays. Instead, its actions are stealthy, calculated, and goal-directed, suggesting a functional distinction between aggression and predation.

However, other researchers propose that predation can be classified as "predatory aggression", particularly when the behaviours involved mimic those seen in aggressive encounters. An example is mouse-killing by rats, where the attack behaviour closely resembles violent aggression rather than typical hunting patterns.

A related concept is aggressive mimicry, where a predator deceptively presents itself as harmless or appealing to its prey before launching an attack. This strategy allows predators to reach their target without triggering a defensive response, increasing their hunting success.

DEFENSIVE AGGRESSION

Defensive aggression is a critical survival response exhibited by many animal species when they perceive a threat from a predator or an external danger. Unlike predatory aggression, which is proactive and goal-directed, defensive aggression is reactive, triggered by an immediate threat. The fight-or-flight mechanism often dictates the decision to engage in defensive aggression, where an animal must assess whether it has the strength to fight off the danger or if escaping would be the safer option. This type of aggression is particularly evident in social animals, where cooperative defence strategies play a key role in ensuring survival.

Communication is a significant component of defensive aggression, as many species have developed sophisticated ways to warn others of an approaching predator. Alarm signals, which can be chemical, auditory, or visual, allow individuals to prepare for an attack by taking a defensive stance or fleeing to safety. Some species, mainly insects and social mammals, use chemical signals to alert others to danger. For example, when under threat, the stingless bee Trigona fulviventris releases a chemical known as Nerol. This pheromone has a dual function: it reduces the number of bees leaving the nest, thereby lowering their exposure to danger, while simultaneously heightening the aggressive response of those that remain, increasing the likelihood that they will bite and attack intruders.

Auditory alarm signals are shared among mammals and birds, where distinct vocalisations serve as warnings of threats. Vervet monkeys, for instance, have developed a sophisticated alarm system with specific calls for different predators. If a leopard is nearby, they emit a distinct call that prompts others to climb trees for safety. In contrast, when they detect an eagle, they produce a different alarm that sends the group running for cover in dense vegetation. Such responses increase the likelihood of survival by allowing animals to react appropriately based on the threat they face. In addition to chemical and auditory signals, some species rely on visual warning displays, such as the tail-flagging behaviour in deer or the stotting (high-energy jumping) seen in gazelles, which serve both as warnings to others and as deterrents to predators by showcasing agility and awareness.

Defensive aggression is not always an individual reaction; in many species, it involves collective action, where group members cooperate to drive away a predator. Some animals release distress signals to warn others and summon reinforcements, triggering a coordinated response against a threat. Meerkats, for example, post sentinels that scan for danger, emitting specific alarm calls to prompt an immediate reaction from the group. Ants and termites engage in swarming defensive behaviour, where a single distress signal can mobilise an entire colony to attack an intruder. Elephants also exhibit a powerful form of collective defence, encircling their young and aggressively confronting potential threats as a unit. This cooperative form of defensive aggression is highly adaptive, ensuring that most of the group survives even if some individuals are lost in an attack.

Defensive aggression serves several evolutionary functions, each contributing to an individual or a group's survival. Many species have evolved intimidating displays to discourage predators before a physical attack becomes necessary. Pufferfish inflate their bodies, cobras spread their hoods, and certain lizards use elaborate threat postures to appear more formidable. For some species, defensive aggression is most pronounced when protecting offspring, as seen in mother bears, who will charge at any perceived threat to their cubs with extreme ferocity. In social animals, defensive aggression is often about more than individual survival; it is crucial in protecting kin and maintaining the group's stability.

Although defensive aggression in animals is primarily instinctive, humans also respond similarly when feeling threatened. However, unlike animals, human aggression is influenced by complex social, psychological, and cultural factors, making it far more variable.

COALITIONAL AGGRESSION

Coalitional aggression refers to group-based aggression, where individuals coordinate attacks against rivals. This behaviour is rare in the animal kingdom but is observed in species with complex social structures, including chimpanzees, dolphins, and humans. While the motivations behind human conflicts may appear different, they ultimately revolve around the same evolutionary pressures seen in other species—competition for resources, territory, and reproductive opportunities.

Several factors influence the likelihood of coalitional aggression. Numerical advantage plays a key role, as groups with more members are more likely to initiate attacks, reducing the risk for individuals while increasing the chance of success. Territorial proximity is another important factor, with conflicts most likely to occur near home ranges, where competition over food, shelter, and mates is most intense. Social structures also determine patterns of aggression, with species that form long-term alliances more likely to coordinate attacks.

Chimpanzees display some of the most striking examples of coalitional aggression. Males within a community patrol their territory and attack rival groups, often targeting isolated individuals in ambush-style assaults. These attacks can escalate into prolonged conflicts, with entire communities wiped out over time. Goodall (2010) documented systematic killings in chimpanzees, showing that such aggression is not random but serves clear evolutionary purposes—securing resources and reducing competition for food and mates.

Dolphins also exhibit coalitional aggression, particularly in mating competition. Male bottlenose dolphins form alliances to control access to females, sometimes attacking rival groups to assert dominance. These alliances can shift over time, but the ultimate goal remains a reproductive success. Unlike chimpanzees, whose coalitions focus more on territory, dolphins’ aggression is often centred around controlling mating opportunities.

Humans engage in coalitional aggression on a much larger scale, but the fundamental motivations remain the same—access to resources, territory, and reproductive success. Although human conflicts are often framed in terms of nationalism, ideology, or religion, these are ultimately extensions of the same underlying evolutionary pressures. Wars are fought over land, wealth, and power, translating into resources and increased social or reproductive advantage for the victors. Like other species, human coalitions form based on mutual benefit, ensuring survival, dominance, and genetic legacy.

While humans may justify war and large-scale aggression with complex ideologies, the evolutionary basis remains consistent with other social species. Coalitional aggression continues to serve the same fundamental function: securing resources and ensuring reproductive success, making it a deeply ingrained part of social and biological competition.

LORENZ’S THEORY OF AGGRESSION: INSTINCT OR RITUAL?

Konrad Lorenz (1966) argued that aggression is an innate biological drive that has evolved to serve important survival functions. However, his work contains an apparent contradiction: while he described aggression as a natural and instinctual force, he also insisted that aggression in animals is rarely destructive. Instead, he claimed that most animal aggression is ritualised, acting as a means of establishing dominance and preventing lethal conflict.

Lorenz believed that aggression, like hunger or thirst, builds up over time and must eventually be released. This idea, the hydraulic model of aggression, suggests that aggression accumulates inside an organism until it finds an appropriate outlet. If aggression is not discharged through controlled or ritualised behaviour, it may erupt in uncontrolled violence. However, in most animals, this instinctive aggression is regulated by built-in inhibitions that prevent unnecessary harm. For instance, many species engage in ritualised combat rather than fatal fights. Wolves rarely fight to the death when involved in dominance disputes; instead, a losing wolf will roll onto its back and expose its throat in submission, at which point the dominant wolf instinctively ceases its attack. Similarly, stags use their antlers in pushing contests to determine hierarchy, yet serious injuries are rare. Birds often use vocal and visual displays to threaten rivals rather than resort to confrontation. Similarly, stags lock antlers and push against each other to establish dominance rather than using their antlers as weapons. Gorillas engage in chest-beating displays, which intimidate and prevent physical fights.

Lorenz’s idea of ritualised aggression was supported by Craig (1921), who noted that aggressive encounters in many animals consist of displays rather than actual combat. These displays allow individuals to establish dominance while avoiding the risks associated with physical fighting. Ritualised aggression is significant in species that live in social groups, as it enables individuals to assert dominance and maintain stability within the group.

Lorenz also suggested ritualised aggression may have evolved in humans through symbolic displays of dominance. Sporting events, military parades, and political demonstrations can all be seen as ritualised aggression that allows individuals or groups to assert their strength without engaging in direct violence. However, unlike animals, humans do not always respond to aggression ritualistically, and violence often escalates beyond mere displays of dominance.

The real danger, he suggested, lies in humans. Unlike other species, humans lack the same innate inhibitions that prevent aggression from escalating to lethal violence. Moreover, modern technology and weaponry allow for long-range attacks where appeasement signals—such as submissive postures or distress cues—are ineffective. This, according to Lorenz, explains why human aggression can result in large-scale warfare, terrorism, and unprovoked killings, phenomena rarely seen in the animal kingdom. By studying aggression in animals, Lorenz believed we could better understand human aggression as an evolved survival mechanism.

Despite this emphasis on restraint, Lorenz also suggested that aggression serves essential adaptive functions. Many later interpretations of his work categorised aggression into four broad motivations: fear, hunger, reproduction, and aggression. These are often mistakenly attributed directly to Lorenz, but they align with his broader arguments about the biological basis of aggression.

FEAR

Aggression is frequently a defensive response to perceived threats, helping animals protect themselves from predators or rivals. Many species exhibit defensive aggression, which involves growling, biting, or attacking when cornered. This response increases an animal's chances of survival by deterring threats or eliminating danger. In some cases, defensive aggression extends to group defence, where social animals, such as wolves or primates, collectively repel intruders to safeguard their territory and offspring.

HUNGER

Predatory aggression is essential for survival in carnivorous species. Unlike other forms of aggression within a species, predatory aggression is directed towards prey and is primarily motivated by hunger rather than competition. This instinctual behaviour is seen in predators such as lions, wolves, and birds of prey, who rely on their ability to hunt and kill for sustenance. Unlike defensive or dominance-related aggression, predatory aggression is calculated and lacks emotional hostility—it is a necessary mechanism for obtaining food.

REPRODUCTION

Aggression is critical in securing mating opportunities, particularly among males who compete to access fertile females. Sexual selection aggression is common in many species, where males engage in displays of strength or direct combat to establish dominance and increase their chances of reproduction. For example, in species such as deer, gorillas, and lions, the most vigorous and aggressive males often secure exclusive mating rights, ensuring their genetic legacy.

AGGRESSION ITSELF

Finally, aggression as an innate drive was central to Lorenz’s theory. He suggested that aggression is not always a direct response to external threats but can build up internally, requiring periodic release. He introduced the hydraulic aggression model, suggesting that aggressive energy accumulates within an organism and must eventually be discharged. If aggression is not released through natural triggers such as territorial disputes or mate competition, it may spill over unexpectedly or inappropriately. Lorenz’s hydraulic model implies that aggression is a biological necessity, like hunger or thirst, requiring periodic release. However, later research has challenged this idea, suggesting that aggression is more flexible and influenced by environmental and social factors rather than an inevitable pressure that must be relieved.

TERRITORIAL DISTRIBUTION

One crucial function often discussed alongside these motivations is territorial aggression, although Lorenz did not explicitly separate it as a category. Many species defend their territories aggressively to secure resources, food, and mating opportunities. This territorial behaviour overlaps with dominance and reproductive aggression, ensuring that individuals maintain control over essential survival assets. Many animals establish and defend territories, providing access to adequate resources such as food, shelter, and mates. This territorial behaviour prevents excessive competition and allows populations to remain balanced within an environment.

Examples include wolves defending pack territory, birds using their song to warn rivals away, and big cats such as tigers marking and patrolling their land to prevent intrusion. By distributing individuals across a more expansive space, territorial aggression reduces the risk of conflict over limited resources.

In conclusion, Lorenz’s work presents a paradox: while he viewed aggression as an instinctual drive, he also emphasised that animals have evolved natural restraints to prevent unnecessary violence. The extent to which his ideas apply to human behaviour remains controversial. While his research highlights critical biological underpinnings of aggression, critics argue that human aggression is shaped by social, cultural, and cognitive factors that go far beyond the instinctual mechanisms observed in animals.

EVALUATION OF RITUALISED AGGRESSION

Marsh et al. (1978) examined football hooliganism, one key study supporting ritualised human aggression. Marsh and his colleagues observed that what may appear to be chaotic, undisciplined mob behaviour among football supporters consists of structured groups with distinct status hierarchies. Young supporters undergo a form of apprenticeship, learning the norms of ritualised aggression over time. As they gain experience, they may be promoted to higher-status groups, continuing a "career" in football-related violence.

However, Marsh noted that despite the outwardly aggressive nature of these groups, physical violence is often avoided. Instead, much of the aggression remains symbolic or verbal. A typical example occurs after matches, where rival supporters engage in choreographed pursuits, shouting threats about what will happen if they catch their opponents. In most cases, however, these threats are not acted upon, illustrating how aggression can be ritualised rather than physically harmful.

COUNTER-ARGUMENT: HUMAN AGGRESSION IS NOT ALWAYS RITUALISED

While Marsh et al. (1978) provide evidence that some forms of human aggression are ritualised, there is substantial evidence that human violence frequently escalates beyond symbolic displays, resulting in severe harm, injury, and death. Unlike many animals, which use ritualised aggression to establish dominance without unnecessary violence, humans often engage in extreme, unprovoked, and premeditated aggression, contradicting the notion that all human aggression follows the same patterns as animal ritualised aggression.

HUMAN VIOLENCE OFTEN ESCALATES BEYOND RITUAL

In contrast to Marsh’s findings on football hooliganism, many real-world instances of aggression do not remain symbolic or structured. Human conflict is often impulsive, emotionally driven, or premeditated rather than restricted to ritualistic exchanges.

• War and Genocide – Unlike territorial disputes in animals, human warfare is not a brief display of strength but often involves mass violence, strategic planning, and extermination of rivals over ideological or economic reasons. Genocides, such as those in Rwanda or the Holocaust, demonstrate aggression that is systematically planned, far exceeding any form of ritualised violence seen in other species.

• Gang Violence – While football hooliganism may contain ritual elements, urban gang conflicts frequently escalate into genuine physical violence, stabbings, and shootings. Unlike ritualistic animal aggression, which usually ends when dominance is established, gang violence often spirals into retaliatory killings.

• Domestic and Criminal Violence – Many forms of human aggression, such as domestic abuse, sexual violence, and murder, do not fit into a ritualised framework. These acts are often motivated by psychological, social, or economic factors rather than following a predictable pattern aimed at resolving competition without harm.

HUMAN ATTACK AND DEFENCE BEHAVIOURS

Morris (1977) observed that human aggression differs significantly from animal aggression in attack and defence strategies.

In attack behaviours, humans instinctively deliver rapid, overarm blows to an opponent’s head despite lacking the specialised anatomical adaptations seen in other aggressive species, such as claws, sharp teeth, or powerful limbs. This suggests that while aggression is innate, human physiology is not optimised for inflicting damage efficiently, and as a result, humans have resorted to using weapons, which in themselves may inhibit empathy.. Tinbergen argued that modern weaponry distances the attacker from their victim, making it easier to ignore distress signals. For example, a terrorist dropping bombs on a distant target might feel less psychological resistance than someone who must engage in direct physical violence.

SUBMISSIVE BEHAVIOURS DO NOT ALWAYS PREVENT ATTACKS

Morris (1977) noted that human aggression differs from animal aggression in both attack and defence behaviours:

• Human attack behaviours: Humans instinctively deliver rapid, overarm blows to an opponent’s head despite lacking specialised anatomical features (e.g., claws, sharp teeth, or powerful limbs) to cause damage efficiently.

• Human defence behaviours: When attempting to appear non-threatening, humans slump their shoulders, grimace, spread their hands, and adopt high-pitched, pleading vocal tones. Morris described this behaviour as "bowing and scraping", an instinctive display of submissiveness.

Submissive gestures are highly effective in halting aggression among animals. For instance, a wolf will cease attacking if its rival rolls onto its back and exposes its throat, signalling complete surrender. Thus, a key feature of ritualised aggression in animals is that submission signals effectively stop further violence. However, in human aggression, submissive behaviours are often ignored, and violence continues even when the victim poses no additional threat, so instinctive displays seem far less effective in humans.

• Prison violence studies show that weaker individuals are often targeted repeatedly rather than being spared after displaying submission, contradicting the idea that ritualised dominance behaviours regulate human aggression.

• CCTV footage of violent assaults frequently shows attackers continuing to strike their victims, even after they have assumed a foetal position, a well-recognised posture of submission and helplessness.

.This suggests that, unlike in most animal species, human aggression is less influenced by instinctive cues to stop attacking, making it more unpredictable and potentially dangerous.

ALCOHOL, DRUGS, AND COGNITIVE FACTORS CONTRIBUTE TO HUMAN AGGRESSION

Unlike animals, human aggression is influenced by external substances, cognitive biases, and social structures that can override ritualistic control mechanisms.

• Alcohol and drug use impair judgment and lower inhibition, increasing the likelihood that verbal confrontations will escalate into physical violence rather than remaining ritualistic. Moreover, Intoxication can impair cognitive processing, reducing an individual’s ability to recognise submission signals and increasing the likelihood of continued violence.

• Social and economic deprivation can create environments where individuals resort to extreme violence for survival rather than engaging in symbolic confrontations.

• Cognitive biases and ideology allow humans to justify unnecessary violence, making them more prone to premeditated and ideologically driven acts of aggression.

• Lorenz argued that ritualised aggression prevents lethal violence, but modern weaponry and technology allow humans to kill from a distance, bypassing natural restraint mechanisms. As societies have evolved, humans have become desensitised to distress cues due to technological and cultural changes, such as living in larger cities.

• Weapons and Technology Remove Instinctive Inhibition: Tinbergen noted that a terrorist might be comfortable dropping bombs from a plane but would struggle to kill a person face-to-face, highlighting the role of technological detachment in human violence.

CONCLUSION: HUMAN AGGRESSION OFTEN TRANSCENDS RITUALISTIC CONFINES

While some socially accepted forms of human aggression, such as sports rivalries and symbolic threats, may mirror ritualised aggression in animals, human violence is frequently uncontrolled, prolonged, and premeditated. Unlike animals, humans have weapons, ideologies, and social structures that enable mass violence, persistent aggression, and destruction on scales far beyond anything seen in the natural world.

Thus, while ritualised aggression can be observed in some human behaviours, it is far from a universal model for explaining human violence.

CHALLENGES TO RITUALISED AGGRESSION: GOODALL'S CHIMPANZEE WARFARE

While Lorenz's concept of ritualised aggression finds some support, it is not universally applicable to all forms of aggression in the animal kingdom. Research by Jane Goodall (2010) contradicts the notion that aggression among animals is always ritualised.

Goodall spent over 50 years studying chimpanzees and documented cases of organised intergroup violence that strongly resembled human warfare. She observed a sustained conflict in which one chimpanzee group systematically attacked and exterminated a neighbouring group over time. This behaviour, which she described as "the systematic slaughtering of one group by another", does not align with Lorenz's idea that aggression is primarily a regulatory or ritualised behaviour to establish dominance. Instead, it suggests that some forms of aggression in the animal world are premeditated and lethal rather than symbolic.

From an ethological perspective, this raises questions about the adaptive function of extreme violence. Unlike simple dominance battles, these attacks posed significant risks to the aggressors, increasing the likelihood of injury or death. Such prolonged warfare challenges the assumption that aggression always serves an evolutionary purpose, as it does not always appear to provide an immediate survival advantage.

DIFFERENCES BETWEEN HUMAN AND ANIMAL AGGRESSION

Despite Jane Goodall's work, ethologists often highlight that most animal disputes are resolved through threat and appeasement displays rather than actual violence. This restraint is less evident in humans, where aggressive encounters frequently escalate into serious physical violence.

CRITICISMS OF THE HYDRAULIC MODEL OF AGGRESSION

Lorenz's hydraulic model of aggression proposes that aggression is an innate drive that accumulates over time and must eventually be released, much like pressure building in a valve. However, this theory has been widely criticised for oversimplifying human and animal aggression and failing to account for key psychological and environmental influences.

IGNORES LEARNING AND SOCIAL FACTORS
One of the most significant criticisms of Lorenz's model is that it fails to consider learned behaviour. Unlike in animals, where instinct is dominant, human aggression is highly influenced by social, cultural, and environmental factors. Bandura's Social Learning Theory (1977) proves that aggression is often learned through observation and reinforcement rather than an inevitable biological drive that builds up and needs to be discharged.

LACK OF EMPIRICAL SUPPORT
Lorenz's idea that aggression accumulates until it is released lacks direct scientific evidence. Research suggests that aggression does not necessarily "build up" over time, as Lorenz described. Instead, it is often situationally triggered, depending on external factors such as provocation, frustration, or environmental cues.

CATHARSIS HYPOTHESIS DEBUNKED
The hydraulic model aligns with the idea of catharsis, which suggests that engaging in aggressive acts reduces aggressive impulses. However, research contradicts this view. Bushman (2002) found that venting aggression, such as punching a bag, actually increases aggressive thoughts and behaviours rather than reducing them. This challenges the notion that aggression must be "released" to prevent it from escalating. Moreover, Unfortunately, such predictions [of catharsis] turn out to be wrong. Couples who argue the most are those who are the most likely to become violent. Husbands who push their wives are those most likely to move on to slapping and punching. The best predictor of an individual's likelihood of criminal violence this year is his criminal violence last year. Violence seems to beget violence rather than decrease it.

VARIABILITY IN HUMAN AGGRESSION
The model assumes that aggression is inevitable and biologically pre-programmed, but studies have shown considerable variations in aggression levels across different cultures and individuals. Some societies, such as the!Kung San of the Kalahari shows very low levels of aggression, indicating that social norms and upbringing play a significant role in aggression control. This contradicts the idea of an automatic build-up.

DOES NOT EXPLAIN NON-AGGRESSIVE RESPONSES
If aggression were instinctual and driven by biological pressure, all individuals should exhibit aggressive behaviour regularly. However, many people experience provocation without responding aggressively. The cognitive and emotional regulation of aggression suggests that it is not an unavoidable force that builds up but rather a response shaped by individual differences, situational factors, and social conditioning.

LACK OF FLEXIBILITY IN HUMAN BEHAVIOUR
Unlike in animals, where instinct governs behaviour more rigidly, humans can override aggressive urges through rational thinking, empathy, and societal rules. The prefrontal cortex significantly inhibits aggression, contradicting the idea that aggression must be released through an aggressive act. Instead, people can redirect aggressive impulses into socially acceptable behaviours, such as sports, problem-solving, or creative expression.

CONCLUSION

While Lorenz’s hydraulic model contributed to understanding aggression as an innate behaviour, modern research indicates that aggression is far more complex than a simple build-up and release mechanism. Psychological, social, and environmental influences are crucial in shaping aggressive behaviour, making situational factors more important than innate drives. As a result, the hydraulic model is primarily considered outdated in explaining human aggression.

INSTINCTIVE BEHAVIOUR SEQUENCES

Ethologists argue that aggression in animals follows innate, pre-programmed sequences of behaviour known as fixed action patterns (FAPs). These instinctive behaviours, triggered by specific stimuli, suggest that aggression has evolved as an adaptive response to environmental challenges such as securing territory, defending resources, or establishing dominance.

Konrad Lorenz and Nikolaas Tinbergen proposed that, like animals, humans may also exhibit innate aggressive behaviours, though human aggression is more complex, flexible, and influenced by social and cognitive factors. While human aggression often involves conscious decision-making, specific automatic responses to threats or territorial disputes may still be rooted in fixed action patterns.

By studying animal aggression, researchers understand whether human aggression is biologically predetermined or shaped by environmental and cultural factors. Some forms of human aggression—such as fight-or-flight responses, territorial disputes, and dominance hierarchies—may share similarities with animal aggression. Still, human violence is often more strategic and premeditated.

INNATE RELEASING MECHANISM (IRM)

Animals often exhibit instinctive behaviours in response to specific environmental cues, known as sign stimuli. These stimuli trigger pre-programmed behavioural reactions, ensuring that animals react swiftly and appropriately to biologically significant events.

One well-documented example of a sign stimulus is observed in male sticklebacks during the breeding season. Male sticklebacks develop a red belly, which signals territorial aggression to other males. When another stickleback sees this red marking, it automatically initiates an attack response, even if the "opponent" is an artificial model. This automatic recognition and response to key stimuli suggest that animals possess an Innate Releasing Mechanism (IRM). This biological system detects sign stimuli and triggers the corresponding fixed action pattern (FAP).

KEY CHARACTERISTICS OF IRMS:

• Instinctive – Animals do not need to learn them; they are born with these mechanisms.

• Automatic – The response occurs without deliberate decision-making.

• Sign stimulus-dependent – The specific trigger activates the response.

EXAMPLES OF IRMS IN AGGRESSION AND DEFENCE:

• Mother birds feeding chicks – When a baby bird opens its mouth wide, showing a bright red interior, the mother is automatically triggered to feed it. The red colour acts as a sign stimulus, and the feeding behaviour is completed even if the chick is removed mid-action.

• Male sticklebacks attacking rivals – The red underbelly of another stickleback acts as a releaser, leading to immediate territorial aggression.

• Dogs responding to prey movements – Many dogs have an instinctual prey drive triggered by rapid movements. This is seen when some dogs instinctively chase cats or other small animals while others do not due to selective breeding or training.

RELEASERS OR SIGN STIMULI

A releaser (or sign stimulus) is an external cue that activates a fixed action pattern (FAP) or stereotyped behaviour in animals. These stimuli are reliable signals for essential survival activities such as mating, defence, feeding, and social interaction.

Animals are susceptible to particular environmental cues, responding instinctively without requiring prior learning. Certain visual, auditory, or chemical signals trigger specific responses essential for survival.

The term Releaser was first introduced by Konrad Lorenz in 1935, who described it as a biological mechanism that elicits instinctive behaviour patterns within members of the same species.

MIMETIC RELEASERS

Some species have evolved strategies to exploit the relationship between a sign stimulus and an automatic response in another species. These deceptive signals are known as mimetic releasers.

A striking example is observed in parrotfish and cleaner fish:

• Actual cleaner fish remove parasites and fungi from the bodies of larger fish, such as the parrotfish.

• When approaching a parrotfish, the cleaner fish performs a distinctive undulating dance, which acts as a sign stimulus. This triggers the parrotfish to assume a tilted cleaning position, allowing the cleaner fish to access its body safely.

• False cleaner fish, however, mimic the appearance and behaviour of true cleaner fish, deceiving the parrotfish into adopting the same submissive posture.

• Instead of removing parasites, the false cleaner fish takes advantage of the moment to attack the parrotfish, biting off small pieces of flesh before escaping.

This mimicry demonstrates how some species exploit innate releasing mechanisms to manipulate the responses of other animals.

SUPERNORMAL RELEASERS

In some cases, artificially exaggerated stimuli can produce a stronger-than-normal response in animals. These exaggerated cues are supernormal releasers and demonstrate how extreme versions of natural stimuli can hijack animals' innate responses.

Examples include:

• Infant gulls and parental feeding: Chicks of various gull species instinctively peck at a red spot on the parent’s beak to stimulate feeding. However, experiments show that chicks will peck even more vigorously at an artificial bill with an exaggerated red spot, demonstrating an increased response to a supernormal stimulus.

• Oystercatchers and egg incubation: Oystercatchers, a shorebird species, typically incubate their eggs. However, when presented with an artificially large egg, they prefer to incubate the oversized model instead of their natural eggs. This suggests that larger eggs provide a more potent stimulus for the bird’s instinctive incubation behaviour.

The existence of supernormal releasers suggests that natural selection has shaped these instinctive responses to specific environmental cues. Still, in some cases, animals cannot regulate their response to exaggerated stimuli.

CONCLUSION

Releasers (sign stimuli) and innate releasing mechanisms (IRMs) are fundamental to understanding fixed action patterns and instinctive behaviour. Animals rely on these hardwired responses to react automatically to crucial environmental cues.

However, the presence of mimetic releasers and supernormal stimuli highlights that these mechanisms can be exploited by deceptive species (as seen in false cleaner fish) or artificial exaggeration (as in supernormal stimuli experiments).

These findings demonstrate how evolution has shaped instinctive behaviours to enhance survival but also reveal potential vulnerabilities in an animal’s ability to regulate its automatic responses.

One of the most significant discoveries in ethology and aggression is the concept of fixed action patterns (FAPs), first identified by Oskar Heinroth and later developed by Konrad Lorenz. Fixed action patterns are innate, automatic sequences of behaviour triggered by a specific sign stimulus (releaser). Once initiated, they proceed to completion without interruption, regardless of whether the original stimulus remains present.

FIXED ACTION PATTERNS: INSTINCTIVE BEHAVIOURAL SEQUENCES

Fixed Action Patterns (FAPs) are instinctive, highly stereotyped behavioural sequences that are characteristic of a species. These behaviours are triggered by a specific sign stimulus (also called a key stimulus or releaser) and, once initiated, run to completion without interruption, even if the original stimulus is removed.

Oskar Heinroth introduced the concept of Fixed Action Patterns, Which Konrad Lorenz, one of the founding figures of ethology, later developed. Lorenz proposed that these behaviours are controlled by Innate Releasing Mechanisms (IRMs), neural circuits that detect specific stimuli and activate the corresponding behavioural response.

Fixed Action Patterns have been extensively studied in animals, particularly in fish and birds, where they serve critical functions related to survival, reproduction, and territorial defence. The classic research of Lorenz and Nikolaas Tinbergen demonstrated that these instinctive behaviours are not learned but are instead hardwired responses that enhance evolutionary fitness.

CHARACTERISTICS OF FIXED ACTION PATTERNS

Lorenz identified six key characteristics of Fixed Action Patterns:

• Stereotyped – The behaviour follows a rigid and predictable sequence, occurring in the same way every time.

• Complex – Unlike simple reflexes, FAPs involve a sequence of movements rather than a single response.

• Species-characteristic—Fixed Action Patterns are specific to a species and occur in all members of that species, usually of a certain age or sex.

• Released by a sign stimulus – A specific environmental cue (such as colour, shape, sound, or movement) triggers the behaviour.

• Triggered and runs to completion – Once started, a FAP continues to completion, even if the original stimulus disappears.

• Independent of experience – The behaviour is not learned but genetically programmed, meaning it occurs without prior exposure or practice.

SIGN STIMULI AND SUPERNORMAL STIMULI

A sign stimulus (or key stimulus) is the specific environmental cue that triggers a Fixed Action Pattern. Depending on the species and the behaviour's function, these stimuli can be visual, auditory, chemical, or tactile.

A supernormal stimulus is an exaggerated version of a sign stimulus that produces a stronger-than-normal response. This occurs when an artificial or exaggerated stimulus triggers a FAP more effectively than the natural stimulus.

For example, Tinbergen’s research on geese showed that greylag geese preferred to roll a giant artificial egg back to their nest over a real egg, suggesting that larger eggs provided a more potent stimulus than the normal-sized eggs they naturally lay.

EXAMPLES OF FIXED ACTION PATTERNS IN AGGRESSION

Fixed Action Patterns are commonly observed in aggressive behaviours, particularly in species that engage in territorial defence or mating competition.

TINBERGEN’S STICKLEBACK STUDY (1951): AGGRESSION TRIGGERED BY COLOUR

One of the most famous examples of a Fixed Action Pattern in aggression comes from Nikolaas Tinbergen’s study of three-spined sticklebacks, a species of fish known for its territorial aggression during mating season.

• During the breeding season, male sticklebacks develop a red patch on their underside, which is a secondary sexual characteristic.

• Male sticklebacks aggressively attack any rival males that enter their territory. However, Tinbergen discovered that they did not respond to the fish itself but to the presence of the red patch.

• To test this, Tinbergen introduced wooden models of sticklebacks—some with a red patch and some without.

• The male sticklebacks attacked the red-patched models, even if they were crude and unrealistic, but they ignored realistic models without a red patch.

This study demonstrated that:

• Aggression was triggered by a simple visual cue (the red patch) rather than a complex recognition of a rival fish.

• The aggressive response was automatic and followed a fixed pattern, continuing until completion regardless of further environmental changes.

• Supernormal stimuli (exaggerated red patches) intensified the response, proving that aggression was hardwired rather than learned.

SURPLUS KILLING IN FOXES

Another example of Fixed Action Patterns in aggression is surplus killing in foxes. When introduced into a chicken coop, foxes often kill all available chickens, even though they only need one for food. This behaviour suggests that:

• The rapid movement of multiple prey triggers an automatic attack sequence.

• The behaviour continues to completion, meaning the fox does not stop killing once it has secured enough food.

This demonstrates how predatory aggression can be instinctive rather than controlled or calculated.

PREDATORY AGGRESSION IN CATS

Domestic and wild cats display instinctive chase-and-attack behaviours that resemble FAPs.

• Fast movement is the key sign stimulus that triggers predatory aggression. Even if the object is not prey, a cat will instinctively chase and pounce on it.

• This behaviour is observed in kittens, who stalk and pounce on moving objects, demonstrating that prey-chasing is innate rather than learned.

These behaviours enhance survival skills by ensuring that hunting instincts are developed early.

OTHER CLASSIC FIXED ACTION PATTERNS

Fixed Action Patterns extend beyond aggression and are observed in a wide range of instinctive behaviours:

EGG-RETRIEVAL IN GREYLAG GEESE

• When a greylag goose sees an egg outside its nest, it automatically rolls it back with its beak.

• If the egg is removed mid-action, the goose continues the retrieval motion, demonstrating that the behaviour runs to completion.

• Supernormal stimuli (e.g., artificial giant eggs) trigger even stronger retrieval responses than real eggs.

BROOD PARASITISM: EXPLOITATION OF FIXED ACTION PATTERNS

Other species can sometimes exploit fixed Action Patterns. Brood parasites, such as the cuckoo bird, exploit the feeding FAPs of other birds:

• Cuckoo chicks hatch in the nest of a host bird, such as a warbler.

• The cuckoo displays an exaggerated begging response (a supernormal stimulus).

• The host bird feeds the cuckoo chick at the expense of its own offspring.

This demonstrates that FAPs can be manipulated if another species mimics the correct sign stimulus.

CONCLUSION

Fixed Action Patterns are hardwired sequences of instinctive behaviour triggered by specific sign stimuli and regulated by Innate Releasing Mechanisms. They have been observed in a wide range of species and play crucial roles in aggression, territoriality, reproduction, and survival.

Studies by Lorenz, Tinbergen, and other ethologists have shown that animal aggressive behaviours often follow fixed patterns, ensuring efficient territorial defence and mating competition. Tinbergen’s stickleback experiment remains one of the most famous demonstrations of instinctive aggression, proving that simple environmental cues can automatically trigger aggressive responses.

While FAPs increase an animal’s fitness by ensuring rapid responses to environmental challenges, they can also be exploited, as seen in brood parasitism. Moreover, supernormal stimuli show that exaggerated versions of natural stimuli can intensify responses, further proving the automatic nature of these behaviours.

Fixed Action Patterns provide valuable insight into the biological basis of aggression and instinctive behaviour across species, illustrating how evolution has shaped automatic responses to survival challenges.

PROBLEMS WITH INNATE RELEASING MECHANISMS (IRMs)

While the theory of Innate Releasing Mechanisms (IRMs) and Fixed Action Patterns (FAPs) has provided valuable insights into instinctive behaviour in animals, several criticisms challenge its validity, mainly when applied to human aggression.

REDUCTIONISM

One of the main criticisms of IRMs and FAPs is that they oversimplify complex behaviours. Innate-releasing mechanisms reduce aggression to a purely biological response, ignoring the influence of environmental, social, and cognitive factors. Human aggression, for example, is not merely a reflexive action triggered by a stimulus but is shaped by emotions, reasoning, cultural norms, and learned experiences.

DIFFICULTY IN MEASURING INTENTION

Another issue with IRMs is the problem of intention. It is difficult to determine whether an animal is acting out of instinct or making a deliberate decision. Since animals cannot verbally communicate their intentions, interpreting their behaviour solely through IRMs and FAPs may lead to inaccurate conclusions.

For instance, when a male stickleback attacks a model fish with a red underbelly, it is assumed that its aggression is purely instinctive. However, other external factors (such as prior experiences, hormonal levels, or environmental conditions) could also influence its response, making it hard to isolate the IRM as the sole cause of the behaviour.

LIMITED APPLICABILITY TO HUMANS

A significant limitation of IRMs is their lack of generalisability to human behaviour. While IRMs may explain animal instinct-driven responses, human behaviour is far more complex, influenced by social structures, cultural norms, emotions, and personal experiences.

Research has struggled to find clear examples of IRMs and FAPs in humans, as human aggression is often regulated by conscious thought, moral reasoning, and societal expectations. Unlike animals, humans can override instinctive reactions through self-control and decision-making, meaning aggression is not an automatic, unavoidable response to a stimulus.

For example, in modern societies, individuals do not always react aggressively when confronted with territorial invasions or threats—instead, they may use negotiation, diplomacy, or legal systems to resolve conflicts. This contrasts with animals, where territorial aggression is often an instinctive and immediate response.

FREE WILL AND HUMAN BEHAVIOUR

Unlike animals, humans possess greater free will, allowing them to regulate their actions based on social expectations and rational thought. While aggression may be partially innate, humans can choose whether or not to act aggressively in response to stimuli. For example:

• A wolf encountering a rival will instinctively display aggression or submission.

• When faced with an opponent, humans may consider multiple options—fighting, walking away, or negotiating—before responding.

This suggests that while some automatic responses exist in humans, they are not as rigid or deterministic as IRMs and FAPs in animals.

CRITICISM OF FIXED ACTION PATTERNS: FLEXIBILITY AND CULTURAL DIFFERENCES

Although ethologists originally proposed that Fixed Action Patterns (FAPs) are universal and rigidly programmed into a species, research suggests that aggression is far more flexible and influenced by environmental and social factors than previously thought. This challenges the idea that aggression is purely instinctive and occurs in a predictable, fixed manner across all individuals of a species.

CULTURAL VARIATION IN AGGRESSION

One of the strongest criticisms of the ethological perspective on aggression is that it does not adequately account for cultural differences. If aggression were innate and governed by fixed action patterns, it should be uniform across all human populations. However, research has demonstrated that cultural and social factors shape aggressive behaviour.

For example, Nisbett (1996) conducted a laboratory experiment that examined how cultural background influences aggressive responses to insults. His findings revealed a stark contrast: South American white males were significantly more likely to respond aggressively when insulted compared to white North American males. This contradicts the etiological assumption that aggression is an automatic response and instead highlights the role of social learning, upbringing, and cultural conditioning in shaping aggressive behaviour.

LEARNING AND ENVIRONMENTAL INFLUENCE

Another key issue with the Fixed Action Pattern model is that it fails to consider the impact of learning and environmental variation on aggression. While ethologists initially believed that FAPs were inflexible, evidence suggests that experiences and environmental exposure modify aggressive responses, making them far less predictable than the etiological model implies.

For example:

• Dogs and prey drive – While some dogs instinctively chase small animals, others do not. This variation is due to training, experience, and selective breeding, showing that environmental influences can modify a supposedly innate behaviour.

• Human aggression and social learning – Unlike animals, human aggression is heavily shaped by cultural norms, upbringing, and learning experiences. A child raised in a violent environment may develop aggressive tendencies. In contrast, another child in a peaceful setting may not exhibit aggression despite having the same biological capacity for aggression.

Because aggression is not entirely fixed, ethologists now acknowledge the limitations of FAPs and instead refer to Modal Action Patterns (MAPs), which allow for greater flexibility and individual differences in aggressive behaviour.

MODAL ACTION PATTERNS (MAPs): A MORE FLEXIBLE APPROACH

A Modal Action Pattern (MAP) is similar to a Fixed Action Pattern but differs in one key way—it allows for variation based on individual experience and environmental influences. Instead of assuming that all members of a species will exhibit an identical aggressive response, MAPs suggest that instinctive behaviours can be shaped and modified depending on the circumstances.

For example:

• Dogs and prey drive – While the instinct to chase may exist in all dogs, training and selective breeding influence how strongly it is expressed. Some dogs will chase aggressively, while others may have been conditioned to suppress the behaviour.

• Human aggression in response to insults – Cultural background, personal experiences, and social expectations influence a person’s reaction to provocation. Two individuals may react very differently to the same insult—one might retaliate aggressively, while another might ignore it or respond diplomatically.

This flexibility in behaviour contradicts the original ethological view that innate biological mechanisms strictly determine aggression. Instead, it supports the idea that aggression is a complex interaction between innate tendencies and learned experiences.

CONCLUSION: LIMITATIONS OF THE ETHOLOGICAL EXPLANATION

While Fixed Action Patterns and Innate Releasing Mechanisms provide valuable insights into animal instinctive aggression, they do not fully explain human aggression. Unlike most animals, humans demonstrate significant variability in their aggressive responses, which are influenced by cultural, social, and learned factors.

The key criticisms of the ethological explanation of aggression include:

• Human aggression is more flexible than animal aggression and is influenced by social learning and cultural norms.

• Ethological explanations assume universality, but research such as Nisbett (1996) highlights apparent cultural differences in aggression.

• Fixed Action Patterns are not permanently fixed—evidence suggests that learning and environmental influences modify aggressive behaviour over time.

Although ethology remains a valuable framework for understanding biological influences on aggression, it fails to fully explain the complexity and variability of human aggression, which is shaped by innate mechanisms and social conditioning. The shift from FAPs to MAPs acknowledges that aggression is not purely instinctive but can be adapted and altered through experience.

EVOLUTIONARY DISADVANTAGES OF FIXED ACTION PATTERNS

Although Fixed Action Patterns (FAPs) provide evolutionary advantages by ensuring rapid and effective responses to environmental stimuli, they also come with significant disadvantages. Because these behaviours are rigid and predictable, other species can exploit them, leading to maladaptive consequences in specific evolutionary contexts.

BROOD PARASITISM: EXPLOITING FIXED ACTION PATTERNS

One of the most well-documented evolutionary disadvantages of FAPs is brood parasitism, where one species manipulates the parental instincts of another species by exploiting their innate releasing mechanisms (IRMs).

A prime example is the European cuckoo (Cuculus canorus), which has evolved to lay its eggs in the nests of other bird species, such as the common reed warbler. The host bird, unable to distinguish the foreign egg from its own, follows its instinctive parental FAPs and incubates the cuckoo's egg as if it were its own. Once hatched, the young cuckoo instinctively pushes other eggs or hatchlings out of the nest, ensuring it receives all parental care and resources.

This phenomenon is an example of a supernormal stimulus, where the cuckoo chick's exaggerated begging behaviour (such as louder calls and a broader, more colourful gape) triggers an even stronger parental response from the host bird. The host parent works tirelessly to feed the parasitic chick, often to the detriment of its biological offspring, which are either killed by the cuckoo chick or outcompeted for food.

CODE-BREAKING: HOW SPECIES EXPLOIT FIXED ACTION PATTERNS

The predictability of FAPs makes them vulnerable to exploitation through a process known as code-breaking. Certain species have evolved to mimic the releaser stimuli that trigger FAPs in their hosts, allowing them to manipulate the automatic responses of other animals for their benefit.

An example of this can be seen in the North American cowbird (Molothrus ater), another brood parasite. Once hatched, the cowbird chick provides a supernormal stimulus by being larger and begging more intensely than the host species' own offspring. This triggers an exaggerated parental response, forcing the unwitting foster parent to prioritise feeding the parasite chick over its own young.

THE MALADAPTIVE CONSEQUENCES OF FIXED ACTION PATTERNS

While FAPs are generally beneficial for survival, they can also become maladaptive when they fail to adjust to new environmental challenges. This is particularly evident when animals rely on innate behaviours rather than learned experiences, making them less adaptable to changing environments.

For instance:

• Nesting birds may feed artificial objects that mimic the appearance of their chicks' beaks if they display exaggerated sign stimuli.

• Insects may attempt to mate with artificial structures if they resemble natural mating cues, as seen in beetles trying to copulate with glossy beer bottles, mistaking them for mates.

• Predators may attack artificial prey if it triggers their hunting instincts, even if the prey is not accurate or beneficial for survival.

CRITIQUE OF THE ETHOLOGICAL EXPLANATION OF AGGRESSION

Ethological explanations of aggression suggest that human aggression is biologically programmed, similar to animal aggression. Konrad Lorenz proposed that aggression is an innate, adaptive behaviour that evolved to aid survival and reproduction. While ethology provides valuable insights into territoriality, dominance, and ritualised aggression, it has been widely criticised for failing to explain the complexity and variability of human aggression.

LIMITATIONS OF THE ETHOLOGICAL PERSPECTIVE

INTERSEXUAL SELECTION AND AGGRESSION FOR MATES

Ethological explanations argue that male aggression in animals primarily arises from intersexual selection, where males compete for mate access. This is often expressed through physical combat or ritualised displays, such as:

• Antlers battle with deer, whereas males fight to secure access to females.

• Vocal confrontations in birds help establish dominance without direct physical contact.

• Chest-beating in gorillas, a display of strength designed to intimidate rivals.

While this theory partially applies to human mate competition, human aggression is not solely based on physical dominance. Unlike animals, humans employ psychological, emotional, and social aggression to compete for mates, including:

• Reputation destruction through gossip, slander, or social exclusion.

• Financial dominance, where status-driven aggression influences mate selection.

• Sexual coercion and premeditated violence are rare in the animal kingdom but present in human societies.

Although rape and sexual coercion have been documented in some animal species (e.g., dolphins, chimpanzees), human sexual aggression is often calculated, premeditated, and shaped by societal norms and power dynamics. The ethological approach fails to account for the role of culture, social structures, and learned behaviours in human mate competition.

KILLING FOR FOOD: PREDATORS VS HERBIVORES

Ethological perspectives suggest that animal aggression is goal-directed and instinctual, primarily seen in predatory species.

• Lions, wolves, and sharks exhibit aggression when hunting and killing for food, driven purely by survival needs.

• Herbivores like deer and elephants show defensive aggression, typically in response to threats or during mating season.

However, in humans, killing is rarely linked to survival. Modern human violence is often:

• It is unrelated to basic needs, such as murder, terrorism, and genocide.

• It is driven by ideology, revenge, or psychological factors, which are not observed in the animal kingdom.

• Highly premeditated, unlike the instinct-driven aggression seen in predators.

While early hunter-gatherers were killed for food, modern human aggression extends far beyond biological necessity, undermining the ethological assumption that human violence is primarily an adaptive survival strategy.

PREMEDITATED VIOLENCE: HUMANS VS ANIMALS

The ethological perspective assumes aggression is instinctive and triggered by immediate environmental stimuli. However, humans engage in deliberate, long-term, and ideologically motivated aggression that far surpasses anything seen in the animal kingdom.

Some animals exhibit strategic aggression, such as:

• Chimpanzees form alliances to attack rival groups.

• Dolphins engage in targeted social violence against weaker individuals.

However, no species other than humans premeditates violence for ideological, religious, or political reasons. Human aggression extends to:

• Revenge killings are often planned and carried out after long periods.

• Terrorism and political assassinations require complex strategies.

• Organised genocide and warfare involving deception, propaganda, and sustained violence.

The ethological approach cannot adequately explain these uniquely human forms of aggression, as animals rarely exhibit calculated, socially constructed violence.

INFANTICIDE IN ANIMALS VS HUMANS

Infanticide is observed in various animal species and is generally adaptive, serving reproductive and survival functions.

WHY DO LIONS, CHIMPANZEES, AND DOLPHINS KILL INFANTS?

• Eliminating Genetic Competition – Male lions kill cubs from previous dominant males to increase their own reproductive success.

• Inducing Estrus in Females – Killing offspring accelerates female fertility cycles, allowing new males to reproduce sooner.

• Ensuring Stronger Offspring – Some female mammals kill weak or sickly infants to prioritise resources for healthier offspring.

However, human infanticide is rarely adaptive or biologically driven. Unlike animals, humans do not kill their offspring for reproductive advantage. Instead, human infanticide is often:

• Linked to mental illness, extreme poverty, or societal pressures rather than biological necessity.

• Socially condemned and legally punishable, whereas, in animals, it is a natural survival strategy.

The ethological perspective struggles to account for human moral reasoning and legal systems, differentiating biologically driven animal behaviours from socially constructed human violence.

MURDERING ONE’S SPECIES: HUMANS VS OTHER ANIMALS

Ethological theories argue that intraspecific killing (killing members of the same species) occurs in animals, but only in specific contexts:

• Territorial disputes (e.g., wolves, tigers, and primates).

• Hierarchical conflicts, where dominant animals kill weaker rivals.

• Reproductive competition, where males kill the offspring of competitors.

However, human homicide, war, and genocide go beyond mere territorial and survival needs.

HOW IS HUMAN KILLING DIFFERENT?

• Murder for ideology or revenge – Humans kill based on abstract concepts, such as religion, nationalism, and personal grievances.

• Genocide – While animals engage in inter-group violence (e.g., chimpanzees attacking rival groups), systematic extermination of an entire population for ideological reasons is uniquely human.

• Organised warfare – Unlike animals, humans develop long-term military strategies, deception, and political systems to sustain violence.

The ethological approach does not explain the psychological complexity and planning behind human aggression.

FAILURE OF ETHOLOGICAL EXPLANATIONS IN HUMAN AGGRESSION

CULTURAL VARIATION IN AGGRESSION

Ethological theories assume aggression is universal, but research suggests cultural and social influences shape aggression differently.

• Nisbett (1996) found that South American males were significantly more likely to respond aggressively to insults than North American males, demonstrating that social norms influence aggression.

This contradicts the ethological assumption that aggression is purely biological and suggests that culture significantly shapes human aggression.

LEARNING AND ENVIRONMENTAL INFLUENCE

Human aggression is more flexible than animal aggression, influenced by education, socialisation, and legal consequences.

Unlike fixed action patterns (FAPs), human aggression is context-dependent and adaptable, meaning that people can learn to suppress or express aggression based on their environment, upbringing, and experiences.

CONCLUSION: THE ETHOLOGICAL PERSPECTIVE IS INCOMPLETE

While ethology provides insights into the biological roots of aggression, it fails to account for the psychological, cultural, and ideological complexities of human violence. Unlike animals, humans plan, justify, and institutionalise aggression in ways that innate releasing mechanisms or fixed action patterns cannot explain.

Key limitations of the ethological approach include:

✔ Human aggression is shaped by social and cultural influences, not just biology.
✔ Premeditated violence, genocide, and terrorism have no direct equivalent in the animal kingdom.
✔ Technological advancements allow aggression to bypass instinctive inhibitions, contradicting Lorenz’s theory of ritualised aggression.
✔ The effectiveness of appeasement behaviours varies between species, making human aggression less predictable than ethology suggests.

Ultimately, while ethology contributes to our understanding of aggression, it cannot fully explain modern human violence, which is far more complex, strategic, and socially influenced than the aggression observed in animals.

TYPES OF RESEARCH ON ANIMALS

OTHER FORMS OF AGGRESSION: STUDIED BUT SOMETIMES ABANDONED FOR ETHICAL REASONS

Scientific studies have explored various types of aggression across species, but some experiments were abandoned due to ethical concerns.

1. Muricide (Mouse-Killing) by Cats – Studies on domestic cats killing mice were halted for ethical reasons.

2. Shock-Elicited Fighting – Inducing aggression through electric shocks was abandoned due to cruelty concerns.

3. Isolation-Induced Aggression – Long-term animal social isolation led to severe aggression, prompting ethical objections.

4. Resident-Intruder Aggression – Studies in rats and primates examined how established individuals react to newcomers, often leading to violent confrontations.

5. Maternal Aggression—Many mammals exhibit aggression when protecting their offspring, a phenomenon that has been studied but is challenging to manipulate ethically.

6. Brain-Stimulation-Induced Aggression (Hypothalamus) – Electrical stimulation of the hypothalamus in animals could trigger aggressive behaviours, though such research was later restricted.

7. Dominance-Related Behaviours in Primates – Studies on social hierarchies in monkeys and apes have shown that dominance-related aggression is crucial to group dynamics.

Discuss ethological research as part of the evolutionary explanation of human aggression.

In his influential book On Aggression, Lorenz (1966) stressed that humans are animals and, therefore, show similar behaviour to other animals. His ethological research could be generalised to humans as part of the evolutionary approach to explaining human aggression.

How: defeated animals find new environments

Or rituals allow animals to know their place in a hierarchy. Top dogs get the girls.

Lorenz proposed four main driving forces behind any animal's behaviour: fear, hunger, reproduction, and aggression. He said that aggression could only occur within a species and not between separate species and that its functions were to ensure sexual selection of the fittest and strongest, ensure the survival of the young, and distribute species evenly into territories. 

Perhaps most notably, Lorenz formulated the idea of ritualised aggression – showing aggression as an assertion of power and maintenance of status. He agreed with the earlier work of Craig (1921), who said that ritualised aggression usually meant the display of aggression but not actual violence.

Morris (1990) declared that animals exhibit a high level of restraint, and Gross (1988) proposed an “appeasement tactic” based on his research on the behaviour of jackdaws.

A01 it

Innate releasing mechanisms

Exam hint: An evaluation point would be to discuss whether animal research can be extrapolated to humans. However, it is important not to dismiss animal research entirely but to advise that caution is required when making comparisons between animal and human behaviour

. Ethology, when applied to human behaviour, is a controversial area of psychology, accused of determinism and reductionism. Lorenz, in particular, has been criticised heavily for his research. In a scathing attack on his work, Barnet (1973) dismissed Lorenz’s research on aggression as outdated, saying it doesn’t “represent the methods or opinions current in ethology.” It has also been said to over-simplify the complex differences between humans and the animals he researched. The robustness of generalisations and the lack of scientific evidence to make such claims were questioned (Lehrman, 1953). 

Lorenz met opposition from Fromm (1973), who believed human aggression could be benign or malignant. In his application of animal behaviour to humans, Lorenz could not explain the malignant aggression that undeniably occurs worldwide. His disregard for malignant, pointless acts of aggression is fascinating for a person who was a signed-up member of the Nazi Party and whose work has been said to support Nazi ideas of “racial hygiene”.

Nelson (1974) believed there were essential factors behind aggression, different to Lorenz’s four: the process of learning, structural causes, and psychological causes. These factors go much deeper into the complex cognitive processes behind aggression than any of Lorenz’s work. 

The main problem with applying ethological research to human behaviour is that there are so many differences between all animals. It seems a big leap to generalise the behaviour of jackdaws, for instance, onto humans because of such obvious dissimilarity. Tinbergen (1968) confirmed the dissimilarity of humans from any other animal, claiming that humans are the only species in which aggression is not part of an elaborate ritual system but instead a desire to harm one another.

Despite its many criticisms, Lorenz's ethological research remains a key part of the evolutionary explanation of human aggression and has considerably influenced popular thought.

Aggression" 

Aggression is a familiar term in common parlance and a key concept in studying human behaviour. In conversation, we may use the word "aggressive" to define a person assaulting another, a carnivorous animal seeking prey, or even a storm wreaking havoc on the earth it passes. The more narrow definition used in psychology is most appropriate for our purposes. Aggression is behaviour whose intent is to harm another. More specifically, aggression is defined as "any sequence of behaviour, the goal response to which is the injury of the person toward whom it is directed. You may notice that this definition, even on the surface, poses a conceptual challenge: How do we know the actor's intent?

While the definition of aggression varies somewhat from author to author, I find it helpful to look at theories of aggression by dividing them into three schools: those that consider aggression as an instinct, those that see it as a predictable reaction to defined stimuli, and those that consider it learned behaviour. The three schools form a continuum along which, at one end, aggression is seen as a consequence of purely innate factors and, at the other end, of external factors. Much of the debate on aggression might be framed as a more general "nature vs. nurture" debate.

Aggression-as-Instinct

Sigmund Freud is a prominent psychologist associated with the aggression-as-instinct school. He considered aggression a consequence of a more primary instinct he called...

Thanatos, an innate drive toward disintegration that Freud believed was directed against the self. If he was right, how is it that we all don't commit suicide? In part, it is because of a struggle between Thanatos and Eros [our innate drive toward life], which, luckily for us, Eros usually wins. But it is also because displacement redirects our self-destructive energies outward; we aggress against others to avoid aggressing against ourselves.

How, then, do people manage to avoid wreaking terrible violence upon one another? The answer, according to Freud, is catharsis: Watching violent events or engaging in mild displays of anger diminishes the aggressive urge and leaves us emotionally purified and calmed.

A great many people think of aggression as instinctual. This is the case even though the public has not read Freud on the subject and probably would not accept his notion of a death instinct, even if they were to become familiar with it. On a popular level, aggression is not seen so much as an outward displacement of an innate internally-directed destructive drive but rather as a universal externally directed drive, possibly connected to a survival instinct, which unites humankind with the animal world. Many go further in assuming that we can look to the non-human animal world to gain a clearer understanding of human aggression.

And that is what several scientists have done, particularly ethologists and socio-biologists. Chief among them is Konrad Lorenz, whose 1966 book On Aggression made a major impact. Its cover offers quotations that are suggestive of this impact. The New York Times heralded it as "one of the most important works of our age," expressing hope that it "be read not only by natural scientists but by Rand Corporation thinkers, members of the Pentagon, pacifists, and presidents...."

Lorenz defines aggression as "the fighting instinct in beast and man directed against members of the same species."[3] He relates it to Darwin's notion of the "struggle for existence": "The struggle Darwin was thinking of and which drives evolution forward is the competition between near relations. At least it does so under "natural -- or rather pre-cultural -- conditions... [because] it is always favourable for the species if the stronger of two rivals take possession of the territory or of the desired female.

Lorenz's study is based largely on his careful research of various animal species, particularly fish and birds and, to a lesser extent, non-primate mammals. In these varied species, he notes a shared instinct to defend territory from encroachment by an animal of the same species, to defeat a rival for a desired female and to protect the young and defenceless of the species. He finds that such aggression serves the animal kingdom well in that it brings about a "balanced distribution of animals of the same species over the available environment"[6], assures that the gene pool is continually modified toward strength, and enhances the likelihood of the young of a species growing to adulthood. In these three ways, aggression helps to preserve the species, regularly improving it to make it more adaptive to the environment. Beyond this, Lorenz attributes aggression to a role in developing the social structure due to its critical role in clarifying the rank ordering of the members of a group. Lorenz sees this as a necessity for developing an advanced social life. Lorenz also attributes to the aggressive drive a range of other functions under the general rubric of "motivation."

The presumption is that the primary functions of aggression accrued to humankind in its pre-cultural state. The problem is that cultural and technological advances have outstripped the inhibitory capacities of the human aggressive instinct. To illustrate this in an extreme form, two male mammals fighting over territory or a female do not fight to the death; the stronger backs off when, the weaker acknowledges his loss by exposing a vulnerable body part. Humankind, however, has produced and perfected lethal weapons delivered far from those being attacked. Sometimes, the attacked do not even know of the attack until the fatal blow has already been struck. Thus, they are unable to capitulate and stave off destruction. The babies in the daycare centre at the federal building in Oklahoma City could hardly have had the opportunity to display their defenselessness to the bomber. Our inhibitory mechanisms were presumably sufficient to allay intra-specific killing when our weapons were limited to our hands and feet. Still, they were not designed to offset the utilization of something even so low-tech as a handgun.

Aggression-as-instinct theorists tend to ascribe a cathartic effect to expressions of aggression. Empirical research, however, tends to cast doubt on this function:

Unfortunately, such predictions [of catharsis] turn out to be wrong. Couples who argue the most are those who are the most likely to become violent. Husbands who push their wives are those most likely to move on to slapping and punching. The best predictor of an individual's likelihood of criminal violence this year is his criminal violence last year. Violence seems to beget violence rather than decrease it