Aggression Flashcards
benefits of having a high rank for female competition/cooperation
Benefits of high rank: Better access to food Better feeding efficiency since they get interrupted less Receive more grooming Get harassed less More likely to receive agonistic support
how high rank has positive effects for female reproduction in geladas
Robin Dunbar studied Gelada baboons and compared rank to matriline size. Found that a large matriline meant higher rank. Higher rank means less harassment, which means less energy wasted fighting. Thus, higher rank increases the number of offspring that an individual has.
how high rank has a positive effect on female mortality in verbet monkeys
Richard Wrangham studied vervets. It was a severe drought. Vervets always sleep in trees at night, and some of the trees are closer to the rare water than others. Because it was such a drought, it became important to survival how close your tree was to the water, and he found that the higher-ranking individuals got the trees closer to the water.
During this drought, more lower-ranking vervets died than higher-ranking; Three out of four higher ranking survived, while only one out of four lower-ranking survived.
how high rank has a positive effect on Female Fertility
Fertility has been linked to higher rank in vervets, macaques, and mustached tamarins, to name a few. In all of these, high-ranking females gave birth more than low-ranking females.
What proximate factors affect patterns of female competition and cooperation?
Kinship: Kin engage in serious aggression less often than non-kin. Also, a substantial portion of cooperative acts are performed between kin.
Rank: High ranking females are more attractive social
partners.
Reproductive state: Lactating females are attractive social partners for both immature and adult females- they receive a lot more grooming than when they’re not lactating. This is probably mostly because the others are trying to get close to the newborn so they’re being nice to the mom.
Also, sexually receptive females receive more grooming and give less, and are also more likely to receive agonistic support from males against other females.
Immigration status: Resident females harass and attack immigrant females in both gorillas and chimps, for example.
gelada vs hamadryans baboon
The gelada baboon:
is a typical old world monkey in that males disperse and females stay.
In these groups, the male is supposed to be the central guy, but he doesn’t have a lot of strong social bonds with the females, who all like each other and groom each other frequently. If the male disappears, the females will usually stay together.
In hamadryas baboons, females disperse and so they have weak bonds with each other.
Most of the strong social bonds in the group are between the male and his females. If the male disappears, the whole group will usually disintegrate.
So while their social organization is pretty much the same, because the dispersal pattern is different, their kinship and social stuff are different.
classic instinct theory
all organisms are born with innate biological tendencies that help them survive. This theory suggests that instincts drive all behaviors.
hence aggression is an ‘instinct’
history of nature : culture developments
- nature: culture dichotomy
2, judeocrhstianism (cain and able; agrictulrusts vs pastoralists/ adam and eve bring sin to world)
- hobbes: nature pessimisim
- roussea; culture pessisms
- goodall; nature optimisim
- lorenz/ebelsfeld; nature optism and group selection
issues with lorenzian aggression
- not supoported by evidence
- aggresion is REACTIVE not spontenanous
- infanticide occurs among non-human animals
- killing of adult consepecifs also occurs among non0human animals like chimps
baby schema
cute babies are protected from aggression due to their cuteness (bigger eyes, bulging craniu,)
hydraulic model
elaborates instinct theory; aggression is the endogenous production of DRIVE-specific eneryg build up that is released by AUTOMATISM
evidence for infanticide/intergroup warefare (2 primatologists)
sara hrdy; infanticide in langurs in abu
jane goodall; the chimps of gombe and intergroup ware fare
role of the olympics/games
ritualized aggression techniques to promote peace
cute traits in babies
large eyes
retreating chins
bulging cranium
non-cute traits in adults
small eyes
long snouts
prominent chins
issues with baby scheme idea
(infanticide; babies are still killed)
when might conspecific killings occur and why in males
- kill neighbours for access to teerritory/food/females
- kill older demales to destroy mother/datughter bond
- kill foreign babies for canniablism
- kill babies of own group for paternity certainity (infanticide)
- kill former tyrants to resolve power struggles/revenge
when might conspecific killings occur and why in females
- reduce competitoin anf food by killing babies
2. grandmothers kill infants to keep daughtesr loyal (female philopatries)
why does infanticide occur in callitrichids
in polyandrous/polygyandrous communal breeding systems; grandmas canniablism/kill grandchildren to ensure that the beta daughter keeps helping the grandma reproduce and not have her own kids
why does infanticide occur in meercats
alpha males give birht to multiple pups= its an allomother system= system evolves to social contracts between older siblings and mom
lorenz in ‘on aggression’
1963; animsl are beter than humans
group selection
traits selected for for good of species; which is why there is no intrapsective killings among animals that are not INSTINCT led (wrong theory)
nazi times and lorenz
group selection promotes nationalistic/purist ideologist whereas ‘cancerous individuals are driven out from the organism of the body’ (jews from german christian societ)
aggression: unproblematic vs problematic (in classic instinct theory)
unprobelmatic= interspecies aggression (predator and prety)
unproblematic; intra specific aggression (male to male competition is godo for the sepcies as it promotes the selection of strong/health dominant individuals)
inhibition to kill consepcics due to….
instinct model= aggression is an instinct and group selection states that animals dont kill actively
lorenz + cultural pessimisim theory
humans= are perverted because we use ‘distance weapons’ (spears, guns) so inihibition to kick in
hence our ‘natural behaviour’ is corrupted
pseudospeciation
when enemies are ‘dehumanized’ or seen as another species to justify aggresive/murderous behaviour towards them
revision of animal agression
- intraspecifc competition leads to killings (e.g. 2 magaques will fight; if one macaque pulls teeth from loser winner kills loser as a secuiry meature as loser would be a higher threat)
- infanticide occurs (problematic animal aggression= goes against protective baby schema)
individual selection theory thinkgers
ronald fisher (runaway sexual selection) jbs haldane (synthethic theory of evolution) gerorge c williams (fitness traidoffs) william d hamilton (kin selection) rovert trivers (reciprocal altruism)
three popularizers of individual selection
richard dawkins adn selfish gene
christian vogel
wolfgang wickler
evidence for infanticide/intergroup warefare (2 primatologists)
sara hrdy; infanticide in langurs in abu
jane goodall; the chimps of gombe and intergroup ware fare
examples of DEADLY aggression in chimps
- leathal rading
- predation
- cannibalism
- revenge killing
- infanticie
genocide in chimp example
1970s gombe; kasakela community wiped out by kahoma community=
intense lethal raides with flattened vegetaiton, corpses, ripped out testicles
predation in chimps
kill colobus monkeys
revenge killing example
senegal chimps kill the former alpha male
sexual selection hypoethesis
own offspring shoudl NOT be killed in infanticide situations like in india
grandma hypothesis
menopausal females protect grandchildrendue to inclusive fitness gain
bruce effect
females kill infants when foreign males take over and comes in
why is there more aggression among males
as there are higher stakes to gain access to females (so are more violent) and greater consequences than just accessing a food resource
stategy and risks of uni male group
- evict other males
- have other males try to evict you
(low intra, high inter-group aggression)
altlernate forms of aggression
not just violent
