lecture 12- social behaviors studyguide.pdf

1 1.What is Aggression? 1. Aggression is defined as an unprovoked attack or hostile, injurious, or destructive behavior, often stemming from frustration. It can also refer to combative readiness. 2. The provided link further elaborates on aggression in horses, highlighting how it manifests in equine...

1 1.What is Aggression? 1. Aggression is defined as an unprovoked attack or hostile, injurious, or destructive behavior, often stemming from frustration. It can also refer to combative readiness. 2. The provided link further elaborates on aggression in horses, highlighting how it manifests in equine behavior. 2 n General - Aggression Aggression can have both beneficial and costly outcomes for animals. Benefits include obtaining mates, food, or territory, while costs may include energy expenditure, injury, or even death. 3 1.Types of Aggression 1. Various types of aggression exist, including social, territorial, predatory, pain-induced, fear-induced, irritable, maternal, and sexual aggression. 2. Each type serves different purposes and may occur in different contexts, such as defending territory or protecting offspring. 4 1.Aggression Within or Between Species 1. Aggression can occur within a species (social aggression) due to conflicts over resources like mates or territory. 2. It can also occur between species, such as in predator-prey relationships or territorial conflicts. 5 1.In General - Aggression and Selection 1. Aggression and associated fighting among animals within the same species can be damaging but serve as a means of selection. 2. Strong, healthy individuals are more likely to succeed in aggressive encounters and pass on their genes to the next generation, contributing to natural selection. 6 7 1.Konrad Lorenz's Theory on Aggression 1. Lorenz proposed a theory in his book "On Aggression" (1966) that aggression arises from an accumulated drive, similar to hunger or thirst. 2. According to this theory, aggression builds up over time and is then discharged through fighting. 8 1.How Does an Individual Resolve an Aggressive Challenge? 1. When faced with an aggressive challenge, individuals may resolve the conflict through various means, such as submission, avoidance, or escalation of aggression. 2. These strategies depend on factors like the individual's dominance status, resource availability, and the potential costs and benefits of fighting. 9 1. 2. 3. 4. Animals kept in isolation may display aggression due to fear and lack of social interaction, highlighting the importance of socialization. Animals can be trained to exhibit either aggressive or passive behaviors, emphasizing the influence of environmental factors on behavior. Early experiences, such as rearing by the mother or conspecific group, can significantly impact aggressive tendencies in adulthood. The slide raises the question of whether aggression, such as "road rage," is primarily influenced by genetic factors or environmental situations, suggesting that both play a role. 10 1. 2. 3. Roosters have been selectively bred for fighting ability for thousands of years, demonstrating the heritability of aggressive traits. However, selection against submissiveness may be more intense and effective than selection for aggressiveness, leading to the culling of submissive individuals and their progeny. The slide raises questions about the effectiveness of selection processes in shaping aggressive behaviors within populations. 11 Chickens raised together in stable social groups from a young age may develop "social inertia," which allows them to live together peacefully. However, fights within allmale flocks can escalate until only one survivor remains, illustrating the complex dynamics of social behavior in animals. 12 Animals selected for aggression may also exhibit physiological adaptations, such as increased stamina and specific anatomical features, which contribute to their fighting ability. These adaptations, such as thicker blood vessel walls, enhance endurance and resilience during combat, highlighting the multifaceted nature of aggression. 13 Research on mice demonstrates that aggressive behavior can be learned through training methods, such as exposing mice to dominant individuals or helpless mice. Fighting mice develop dominance hierarchies based on previous combat experiences, indicating the importance of social interactions in shaping behavior. 14 15 16 1. 2. Dominant mice exhibit stronger excitatory synapses in the medial prefrontal cortex compared to subordinates, suggesting a neural basis for social dominance and aggression in mice. This research provides insights into the neurological mechanisms underlying aggressive behavior and social hierarchy formation in animals. 17 18 Images and videos depict various animal species engaging in aggressive behaviors, such as giraffes sparing and gemsboks fighting for access to mates and territory. These examples highlight the diversity of aggressive behaviors observed in nature and their importance in social interactions, resource acquisition, and territory defense. 19 20 21 22 chimpanzee Aggression: Videos and images illustrate violent attacks and territorial battles among chimpanzees, emphasizing the evolutionary significance of aggression in primate societies. The slide underscores the adaptive nature of territorial conflicts and the role of aggression in maintaining social structure and dominance hierarchies among chimpanzees. 23 24 25 26 27 28 29 30 31 32 33 1. 2. Mating in chickens often begins with an aggressive act, where a rooster approaches another bird, either male or female, in an aggressive manner. The response of the approached individual determines whether the encounter escalates into a fight, a sexual encounter, or ends without further conflict. 34 If a rooster approaches another rooster in a challenging or waltzing manner, the second rooster may respond by signaling submissiveness, remaining neutral, or initiating a conflict. 35 When a rooster approaches a hen, he exhibits aggression similar to his behavior towards another rooster. The encounter's direction depends on the hen's response, which may involve escaping, moving aside, or crouching to invite sexual activities. 36 1. 2. Encounters between two hens follow similar possibilities as those between two roosters, with avoidance, neutrality, or challenge being potential responses. Within stable social groups, dominance hierarchies may minimize actual fighting among individuals. 37 38 Various behaviors exhibited by male and female chickens, including crowing by males, preening by females, displacement behaviors, wing-flapping, and face-offs between males. 39 40 41 42 1. 2. The mating sequence in chickens involves courtship behaviors by the rooster, followed by responses from the female, such as escaping, avoiding, or inviting mating by crouching. The rooster often grasps the hen's neck prior to mounting, followed by mounting, treading, and completion of mating. 43 44 Aggression is a complex behavior exhibited by animals, including humans, characterized by hostile, injurious, or destructive actions towards others. It can manifest in various forms and contexts, influenced by genetic, environmental, and social factors. Here's an overview of aggression, its types, characteristics, heritability, and its role in mating among primates: 1.What is Aggression?: 1. Aggression refers to unprovoked attacks or hostile behaviors directed towards others, often arising from frustration, competition for resources, or territorial disputes. 2. It can include physical attacks, verbal threats, displays of dominance, or other aggressive behaviors aimed at asserting control or causing harm to others. 2.Types of Aggression: 1. Social Aggression: Intraspecific aggression occurring within the same species, often related to competition for mates, resources, or social status. 2. Territorial Aggression: Defense of territory against intruders or rivals to secure access to resources or mates. 3. Predatory Aggression: Aggressive behavior aimed at capturing or killing 45 prey for food. 4. Pain-induced Aggression: Aggression triggered by pain or discomfort, such as defensive behavior in response to injury. 5. Fear-induced Aggression: Aggression elicited by fear or threat perception, aimed at self-defense or deterring potential threats. 6. Irritable Aggression: Aggression resulting from frustration or irritability, often triggered by stressors or perceived obstacles. 7. Maternal Aggression: Protective behavior displayed by mothers to defend offspring from perceived threats. 8. Sexual Aggression: Aggressive behavior associated with mating rituals, competition for mates, or mate guarding. 1.General Characteristics of Aggression: 1. Aggression can be influenced by factors such as genetics, hormones, early experiences, socialization, and environmental cues. 2. It serves various adaptive functions, including resource acquisition, defense, establishing dominance hierarchies, and securing reproductive opportunities. 3. Aggressive behaviors can range from subtle displays of dominance to overt acts of violence, depending on the species, context, and individual characteristics. 2.Is Aggression Heritable?: 1. Aggression can have a heritable component, as evidenced by selective breeding experiments in animals like roosters, where fighting ability has been bred for over generations. 2. Physiological adaptations associated with aggression, such as increased stamina and specific anatomical features, can also be heritable traits. 3. Studies on mice have shown that aggressive behavior can be learned and modified through training, indicating a complex interaction between genetic predisposition and environmental influences. 3.Aggression in Primates: 1. Aggression is common in primate societies and serves various functions, including establishing social hierarchies, defending territory, and securing access to mates. 2. In species with complex social structures like chimpanzees, aggression plays a crucial role in maintaining social order, resolving conflicts, and negotiating dominance relationships. 3. Aggression in primates can be influenced by factors such as sex, age, reproductive status, social rank, and availability of resources. 4.Mating and Aggression: 1. Aggression can be intertwined with mating behaviors in many species, where competition for mates leads to displays of dominance, territorial defense, or ritualized combat. 45 2. Mating strategies may involve aggressive displays to intimidate rivals, attract mates, or establish reproductive access. 3. In some cases, mating may occur through forced copulation or coercive behaviors, highlighting the complex interplay between aggression and sexual selection in animal mating systems. Overall, aggression is a multifaceted behavior with diverse forms and functions across different species. Its expression is influenced by a combination of genetic, environmental, and social factors, and it plays a significant role in shaping social dynamics, resource allocation, and reproductive success in animal populations. 45