aggression Flashcards
how is aggression a primary role in natural environments?
Adequate supply of scarce resources
Obtain food
Access to mate
Social hierarchy
true or false: aggression is a unitary phenomenon
false
when can aggression be desirable
Social or Dominance related
Fighting to establish dominance hierarchy to minimize serious combat
what do you see in an established hierarchy
subtle threats vs physical violence
what happens when you pen together novel animals?
intense aggressive encounters
several days to establish pecking order
true or false: Alpha animal rarely challenged by subordinates
true
who is the only one challenged by alpha?
beta
what happens when the pecking order is established?
stare or threat
what is ritualized aggression?
Assertion of dominance in absence of physical combat
Social dominance expressed over:
Food
Mate
Resting place
Action by one animal perceived as threat by another
what is the purpose for territorial aggression
Keeps others out of particular area
what does pain-induced aggression develop directly out of?
pain or fear of pain
what is the function of pain-induced aggression?
Reduce pain by eliminating the source
what happens in terms of pain-induced aggression with a cat with a broken leg?
Won’t discriminate between pain from break & pain induced by vet
what does stoic mean
less likely to react
if pain is severe, what will more stoic breeds/species do?
bite or kick
define pain and examples
animal faces more sensory receptors per unit surface area
ears, rectum, bone fracture, surgery
what are some irritating fluids that induces pain
ketamine
true/false: fear induced aggression can be related to pain
true
define neophobia
fear of unknown
what is fear induced aggression usually accompanied by?
physiological and visceral signs
what is the purpose of maternal aggression?
protection of young
true/false: maternal aggression cannot equal ferocity of male attack
false
what is predatory aggression?
directed towards another species to obtain food
what happens with fully satiated cats and predatory aggression
will often hunt and not eat the catch, not entirely governed by hunger
what are genetic factors of aggression and especially in what animals?
Dominance influenced by heredity
Dogs, horses, cattle
Dogs have short generation interval
which dog breeds have short generation interval
Truculent breeds
what are two factors that can lead to aggression
crowded and hunger
what are environmental controls of aggression
Hunger & crowding
Decreasing enclosure size ◼ Feeding time
Unpredictability of feeding time
define SSRI
selective serotonin reuptake inhibitor
should have a calming effect on animal and reduce aggression
more serotonin hanging around in neurochemical junction so effect will be longer lasting
how is serotonin a neurochemical control?
may inhibit aggression in cats
how is prozac a neurochemical control
serotonin enhancing
how is tryptophan a neurochemical control
precursor to serotonin
true/false: serotonin levels are lower in CSF (cerebral spinal fluid) in nonaggressive dogs
false, in aggressive dogs
describe rationale of low protein diets
Allow more tryptophan to cross BBB & thereby increase brain serotonin levels
why are males more aggressive than females
testosterone
name and describe the 2 roles in aggression
- Very early development
Establishes heightened potential for aggression - Activational effects of androgens
Exposure of androgens in adulthood increases probability that male will show aggression
what is delayed & reduced aggression?
Long-lasting social tolerance & preference for particular individuals
what is an example of delayed & reduced aggression
Twin calves maintain close bond
Calves reared together
◼ Form strong preference for one another
◼ 12 months
- Strong affiliative acts, 1⁄2 agonistic acts
describe aggression in animals that are raised together
exhibit much less aggressive behavior
toward one another when feeding
list the things that happen when group living animals mature
Social tolerance ↓
Agonistic behavior begins
Social hierarchies form
when do calves that are raised together from birth establish a pecking order?
9 months
list what happens with aggression during early and continuous association
Greater social tolerance
Delayed onset of aggressive behavior
Relatively slow formation of social hierarchies
what is testosterone
physiologic agent responsible for masculinization & ↑tendency for aggression
what are some characteristics of secondary sexual dimorphism in terms of male sex hormones
Larger, more powerful males
Presence of functional testes
Testosterone
what is a peck right
one individual of a pair constantly avoids or behaves submissively when threatened or attacked by the other
40 cockerels were subdivided into 4 groups
3 groups castrated at 9 days
Injection of androgen into 2 groups
Observed groups for mean age when peck-rights established
what was the result with the untreated capons?
Pecks of low frequency & intensity
Peck right formation 4 weeks later than intact males
Capons injected w/ testosterone developed peck rights earlier than intact males
what can the genetically produced differences in levels of aggression on male sexual activity be caused by?
differences in physiological responsiveness to androgen stimulation
what was the result from the research from ortman and craig that selected for high and low social dominance ability? 5 generations were selected that differed in strains of aggression dominance and subdivided, androgen injection at different levels, and pair contests between males of high and low social dominance
- Androgen injection ↑ agonistic activity in males deprived of endogenous hormone
- Males of aggressive strains more likely to win pair contests when matched with low aggression strains (receiving same amount of androgen)
what is the take away from the research from ortman and craig injecting androgen at different levels and pair contests?
changes produced by genetic selection primarily caused by changes in physiological responsiveness vs. androgen secreted by testes
what is an example of aversive stimuli?
pain
animals show _______ aggression from pain
reflexive
why would animals be more likely to attack another animal if face to face and receiving shock to feet
they perceive pain as being caused by other animal
castrated male rats decreased fight over time, what does this suggest about testosterone?
plays part in reflexive aggression
what happens if you were to remove the outer cerebral cortex of cats?
Excessive defensive reactions
“sham” rage
Resembling fear & anger
Minor stimulation by touching the cat
what is the function of the cerebral cortex in terms of aggression?
Inhibitory effect on such aggressive behavior
what happens if you remove the amygdala or damage to parts of hypothalamus of a cat
Cats were sleepy or docile
Difficult to arouse to aggressive behavior
what is the amygdala
Part of limbic system
Complex of nuclei beneath cortex
Abundant bilateral connections with hypothalamus
what part of the brain is associated with olfaction in lower animals
amygdala
list what happens when the amygdala is stimulated
Changes in arterial pressure Changes in HR Defecation/micturition Piloerection Involuntary movements Licking, chewing Rage Excessive sexual activity
what disorder is caused by the removal or destroying of the amygdala?
kluver-bucy syndrome
- “bilateral temporal lobe disorder”
what are the characteristics of Kluver-Bucy syndrome
Excessive tendency to examine objects orally Loss of fear Decreased aggressiveness Tameness Changes in dietary habits ◼Herbivores become carnivores Excessive sex drive
◼ Animal not afraid of anything ◼ Extreme curiosity about everything ◼ Forgets very rapidly ◼ Tendency to put everything in its mouth ◼ May try to eat solid objects
what may the animal try to copulate if it has kluver-bucy syndrome?
immature animals
animals of wrong sex
animals of different species
what is the overall function of the amygdala?
◼ Behavioral awareness area that operates at a semi- conscious level
◼ Seems to project one’s present status in relation to both surroundings and thoughts
◼ Help pattern animal’s behavioral response s that it is appropriate for each occasion
what is used to experimentally stimulate the brain
electrodes
what parts of the brain are stimulated when stimulated via threat, attack, escape?
amygdala and hypothalamus
when do dominant animals tend to be very aggressive?
when hungry & competing for food or frustrated in feeding attempts
What causes aggression when animals frustrated?
Excitement & moving around
Individuals encounter each other at higher
frequency than usual
when will the personal space of dominant animals may be invaded by subordinates?
animals attracted to the same scarce resource
