Evolutionary and Genetic Influences on Aggression Flashcards
(96 cards)
1
Q
What is evolution?
A
An scientific explanation of inherited characteristics in organisms (cellular level). These help distinguish species and can be positive (survival) or negative (extinction).
2
Q
What are some pre-Darwin solutions to evolution?
A
Degeneration of species into each other
Organism modifications down to the cellular level
Lamarck - Parents chose their children’s characteristics for better environmentally survival
God’s Will
3
Q
Why weren’t pre-Darwin solutions accepted by the wider world?
A
No hard evidence
4
Q
What lead to Darwin’s “the survival of the fittest” theory?
A
He considered not all of he same organism would survive in a particular environment or even til reproduction - pivotal point.
5
Q
Was Darwin the only one with this theory?
A
Wallace -1958- sent Darwin his ideas about the same theory though they came up with them separately
6
Q
What is natural selection?
A
Some characteristics are better suited to a particular environment and therefore those organisms with those characteristics are more likely to reproduce.
7
Q
What are some of Darwin’s key points about organisms?
A
They have more offspring than required.
Some characteristics aid survival
Some characteristics are inherited.
8
Q
What did Darwin say about characteristics?
A
They aided survival chances until reproduction meaning that particular characteristic would be more prominent within the gene pool and become more common later on in the genetic line. The opposite would happen to ill-aiding characteristics and therefore those characteristics would die out.
9
Q
What is an example of Darwin’s explanation of characteristics?
A
Finches with their beaks and environment - Suitable beaks become more prominent in order to aid survival
10
Q
What are some other explanations of how organisms adapt in terms of inherited characteristics?
A
Genetic mutation - changing species or leading to new species
Random changes in passed on genes - genetic drift
11
Q
How does genetic drift work?
A
If there is variance of genes within the species, genes become categorized. Variation comes form mutations but this is always small as many organism share most of the same genetics and characteristics ie. fight or flight.
12
Q
What is genetic mutation?
A
Can be visible, have no obvious effect or prevent proper genetic function.
May not always be beneficial or visible: reason for DNA repair mechanism but this could also cause mutations
13
Q
Why are mutations beneficial?
A
Advantageous mutations will change the genetic pool and could, in the long term, lead to a new species.
14
Q
Where do you get mutations from?
A
Internal source or external sources ie. carcinogens (cancer)
15
Q
Why is mutations only partially applicable to survival of the fittest?
A
Origin genes could also aid survival due to their “fit” characteristics.
16
Q
What do we already know about an offspring’s genes?
A
They are 50/50 to each parent
17
Q
What is the element of chance?
A
Some genes are lost - this reduces genetic variation and therefore by association, the gene pool
18
Q
What did Fisher and Kimura think of the element of chance?
A
Fisher (1930) believed the element of chance was a minor setback in terms of evolution, in comparison to genetic mutation and natural selection.
Kimura (1968) on the other hand, believed it had a important role and is a factor in genetic changes in species.
19
Q
Where do our characteristics come from?
A
Contrary to popular opinion, they mostly come from the environment rather than your genetics. Many are a combination of the two ie. height which can be affected by nutrition (nurture)
20
Q
What forms the basis of natural selection?
A
Some advantageous characteristics are passed down from parent to offspring through reproduction.
21
Q
Why has natural selection theory been criticized?
A
On the basis of animal observations, they also use altruistic behaviour such as warning others of danger. This contradicts natural selection in that a group is more important than a single individual.
22
Q
How can you contradict the critics of natural selection?
A
Their critic doesn’t go against natural selection as animals warned are most likely family. In this way, genes of the individual are still passed on.
23
Q
What is the critics of the critics know as?
A
Kin selection Theory
24
Q
Define direct fitness
A
individual’s genes are passed on when it survives long enough to reproduce
25
Define inclusive fitness
Individual's genes are passed on through relatives who survive long enough to reproduce
26
How is natural selection an example of adapting genetics?
They aim to survive the environment, rather than through a single individual. Disadvantaged genes may become advantageous in this way.
27
How can disadvantaged genes be advantageous in a group setting?
The closer an animal is to those around it, the more beneficial it is for it to use self-sacrificing behaviour to ensure the survival of the genetics
28
What are some examples of altruistic animals?
Vampire bats, ground squirrels and dogs
29
What is group selection?
Behaviour that protects the group thereby benefits the individuals within it as they may not otherwise survive individually ie. by gaining protection from predators or protecting resources
30
What did Wilson advocate?
A group can take care of offspring (multi- generational society) as they will have divisions in labour. As a community, they could take care of all necessary work
31
What is Eu-social?
The success of living within a group leads to survival of genes which promote co-operational behaviour.
32
What are some examples of eusocial behaviour?
Ants and bees
33
What is an interesting fact about eusocial behaviour?
Some species have evolved to not reproduce as this isn't their function within the community but their roles are passed on via behavioural traits within genes - this goes against natural selection in a way
34
What are some problems with group selection theory?
The survival of any group using normal living conditions rather than eusocial cannot be explained using group selection theory - Human social behaviour is better explained as an individual who finds a group in order to gain better survival opportunities rather than survival of an individual's gene.
It is an over generalised theory.
35
What does group selection theory suggest?
Social organisms are better within a group which they support by inserting themselves within a role but this goes against the idea of equality
36
What are the strengths of natural selection as a theory? (2)
Time resistant with evidence suggesting inherited characteristics to be possible through reproduction ie. Darwin's Beagle Voyage (finches) and Kettlewell (1950s) found more camouflaged moths lived until reproduction age in comparison to non-camouflaged moths
Darwin used a good scientific method and reduces behaviour to genes and so we can focus on the genotype - learned and inherited characteristics can be observed
37
What are the weaknesses of natural selection as a theory? (3)
With reductionism, you cannot get the bigger picture - though behaviour can be observed and learned by associated, it doesn't account for all behaviour ie. kin selection theory but you can also say he didn't mean for it to cover everything
Wanted to confirm his theory rather than falsify it - falsifying it could lead to more proof
Creationism - beliefs are just as important as science
38
What does natural selection about human emotion?
Aggression and peace are human traits are have evolved, as much of our emotions, in order to survive ie. peace allows better chances of survival as its easier to fight off predators and live a longer life span
39
How does aggression allow for survival?
In order to protect mates, offspring, resources and fight off rivals
40
Why is mates' aggression logical?
Jealousy is evolutionary as another male would threaten the need for reproduction and therefore needs to be dealt with.
41
What is a research study in jealousy in males?
Blass and Shackleton (1977) gathered evidence of male response to threatened relationships - male gives into female (debasement) and threatens other males (inter-sexual threats).
In terms of relationship maintenance, women threatened leaving and "taken" vocabulary.
42
What does Blass and Shackleton 1977's study not explain?
individual decision making but instead explains current inherent behaviours present in both sexes.
43
What did Dobash and Dobash's 1984 study find out?
violence against women usually stemmed from sexual jealousy, leading to aggression
44
What is a reason for aggression?
Limited resources to defend successfully for longer would have longer life spans and be able to reproduce.
45
Why are aggressive individuals more likely to pass on their genes?
They are seen as "stronger" especially when within a social hierarchy
46
What are the strengths of seeing aggressive evolution as a theory? (3)
Can explain aggression with evidence
Used scientific methods - careful observations (visible behaviour only)
Scientific credibility - widely accepted and considered an important theory
47
What are the weaknesses of seeing aggressive evolution as a theory? (3)
They protect their offspring but by putting themselves at risk - it wastes energy and resources (counterproductive)
Can be used as a criticism of other theories explaining behaviour
Unflexible
48
How could high openness be seen as an adaptive trait? (3)
People moved around and exploited the resources available so had to be creative.
Could help the clan find better places to stay or better resources due to their curiosity and willingness to find and try new things.
Being creative about creating new tools such spears, bows and arrows.
49
How could high openness be seen as a maladaptive trait? (1)
Each family had a certain set of traditions and customs so openness to experience may not have helped them in those situations
(doing something different and being open will expose them to more harm)
50
How could high consciousness be seen as an adaptive trait? (3)
Very efficient in tasks they do like hunting so it would help them survive.
Take on responsibilities within the clan such as food distribution which makes them a good leader.
Everyone is doing their own role well.
51
How could high consciousness be seen as a maladaptive trait? (2)
Refraining from impulsive behaviour and actions could put individuals in danger as that lifestyle relied heavily on spontaneous reactions.
Poor Prioritisation
52
How could high extroversion be seen as an adaptive trait? (2)
Outgoing and sociable so it will be easier for them to join a clan and find a mate.
May get bored easily but will have constant tasks to complete ie. hunting, cooking, raising children etc.
53
How could high extroversion be seen as a maladaptive trait? (1)
Individuals were careless when exploring, searching for stimulation and therefore putting themselves and others in potentially dangerous situations, particularly as humans would frequently move to new and unfamiliar places.
54
How could high agreeableness be seen as an adaptive trait? (3)
friendly and well liked by others so if they were in need, they would be more likely to be helped and find a mate.
Seeing as people lived in groups with their family or their ‘clan’ then being highly agreeable would mean they would be able to nurture children well and raise them.
More cooperative people, suitable for group work needed for survival
55
How could high agreeableness be seen as a maladaptive trait? (3)
Trusting wrong individuals who'd take advantage of friendship to steal the other clan’s food and resources.
May find it harder to deal with conflict, such as fights between clans
Being selfish and an individualist would have benefited the primitives more, they would have more food to themselves and their hostility would keep them alive. The people with an agreeable personality would not be like this and therefore were less likely to survive and reproduce
56
How could high neuroticism be seen as an adaptive trait?
Could keep the person safe due to the lack of trust that could possibly come with this trait against possible threats
May make a person less likely to take careless risks so keeping them out of danger
57
How could high neuroticism be seen as a maladaptive trait?
Higher risk of anxiety,depression and anger which may cause problems within groups or ‘tribes’
Decrease their time of survival due to these emotions possibly being overwhelming especially in their ‘nordic’ and ‘hunter gatherer’ lifestyle.
58
Which pieces of research help verify the claim that aggression evolved because it helps individuals to compete for resources like food? - Lorenz 1966
Lorenz (1966) observed that when food supplies are reduced, many species become more active in marking and defending territory and become more ready to attack con-specifics (members of the same species).
59
Which pieces of research help verify the claim that aggression evolved because it helps individuals to compete for resources like food? - Allen 2016
Allen et al. (2016) correlated environmental conditions over long periods with archaeological evidence from prehistoric graves. They found that in times of famine or drought there was more evidence of violent death (e.g. sharp force trauma on bones).
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How does the aggression evolution theory with an explanation of limited resources' evidence help prove this? - Lorenz 1966
Lorenz (1966) says reduction of food leads to hostility and therefore aggression: this is important as resources are key to a species’ survival chances. Competition is a result of aggression over entitlement of resources to individuals: those with resources become more territorial and defensive, showing that aggression is advantageous in this method of survival. Natural selection and descent with modification, means that over time, this gene is more common within the gene pool and therefore more present in future individuals of that same species. Through descent with modification, offspring gain parent’s successful survival genes and thereby the circle goes on. Lorenz saw species become readier to attack over scarce resources – survival genetics’ traits are then implemented.
61
How does the aggression evolution theory with an explanation of limited resources' evidence help prove this? - Allen 2016
There is more competition for food in prehistoric times, and therefore aggression is used as a means of survival. This explains why it is still a trait in today’s society, as aggressive individuals were more likely to survive and pass on genetics as proved by Allen (2016): there were more violent deaths during famine (aggression fighting for food). He suggests when in competition for limited resources, there is aggression (shown by deaths). It’s a god example supporting aggression evolution theory as it helps individuals win the competition for resources needed by survival – those with better resources have a higher chance to reproduce and pass on their genetics.
62
Which pieces of research help verify the claim that aggression evolved because it helps individuals to protect their offspring? (2)
Puts et al. (2016) observes that human males are larger and more aggressive than females, suggesting that human males evolved to use aggression to compete with other males.
Buss (2000) found that men are more bothered by sexual infidelity than women and that intimate partner violence is often precipitated by a man’s fear of infidelity or of losing his partner.
63
How does the aggression evolution theory with an explanation of protection of offspring evidence help prove this? - Buss 2000
Buss (2000) suggests that males need to be certain of the paternity of their offspring and not waster resources on another male’s child however he also explains that male aggression could also be due to the innate yearning to reproduce and pass on genes. This trait is passed on through genes as it allows a male to successfully find a female mate hence when a male is threatened in a relationship, his aggression is vented to the male who poses a threat. On the other hand, females may not choose overtly aggressive males, as it may prove to be a detriment to the offspring and will have to compete for her hand.
64
How does the aggression evolution theory with an explanation of protection of offspring evidence help prove this? - Putts 2016
Putts (2016) makes it factually accurate as well as seeing it a noticeably visible trait of most males. Men have evolved with aggression for effective survival. World wars could be linked to this as those who were successful and won battles, were rewarded which led to aggression as a positive, adaptive trait which is then proliferated through genes by parents that reproduce and genes their offspring have through descent with modification or assortative mating. However, women aren’t given the same opportunities to fight and compete and so cannot form a sturdy conclusion – society and the environment also have an influence on aggression.
65
Which pieces of research help verify the claim that aggression is a behavioural trait that is learned? (2)
Bandura et al. (1962) found that children would readily imitate aggressive acts they had seen an adult perform against an inflatable doll, if given the opportunity to do so.The evidence in support of evolutionary theories is correlational, and therefore does not show a causal relationship. For example, there is a correlation between droughts/famines and evidence of violent death in the historical record. This does not tell us the direction of causality.
Much of the evidence that supports the view that aggression is an evolved response comes from studies that compare the human brain and behaviour with those of other species. Feminists have suggested that evolutionary theories justify male violence against women by presenting it as natural and inevitable.
66
How does the aggression evolution theory with an explanation of behavioural trait evidence help prove this?
Bandura (1962) found children exposed to aggressive behaviour becomes more aggressive in nature themselves through imitative acts they’ve seen a role model perform. Their evidence is correlational and therefore has no causal relationship ie. correlation between droughts and famine and aggression levels. Feminists suggest evolutionary theories justify male aggressive behaviour as natural and inevitable which is detrimental to society and life in general.
Evidence suggests the organism’s aggression is environmentally inherited, rather than genetically inherited. Bandura (1962) suggests human aggression’s main reason is its levels within our environment. Evolutional theories ie. Natural selection are correlational and doesn’t explain the causes of aggression (theory based rather than actual statistics and facts). Studies support this aggression ideology based on conclusion of information on comparison of brains (humans vs other ) though this may into be as valid as they have different survival threats.
67
Which pieces of research help verify the claim that aggression is a physical aspect, conducted in certain areas of the brain ie. the amydala? (2)
Raine et al. (1997) found that activity in specific brain areas, such as the amygdala, is associated with aggressive and violent behaviour. The same correlation has been found in many other mammals, including primates (apes and monkeys), cats, dogs and rodents.
Kennedy et al. (2008) found that male mice found it rewarding to engage in aggressive behaviour against other males. These confrontations triggered the release of dopamine in the animals’ reward pathways.
68
How does the aggression evolution theory with an explanation of physical aspects of brain involvement (amydala) help prove this?
Raine (1997) conducted study and found association with aggression and specific areas of the brain. This supports the idea of evolutionary aggression as humans had evolutionary aggression through parts of their brain through generations in order to help them survive the EEA.
Kennedy (2008) conducted an experiment on male mice with the conclusions that male mice’s aggressive confrontations released dopamine in the reward pathway, making it a rewarding behaviour which has been evolved. This could be a reason due to limited resources to survive the EEA or the search for a mate, therefore their indirect or direct aggression made it more likely for them to survive. If we find something to be rewarding, we continue to do it!
69
Why do we use twin adoption studies?
They are used to study genetic influences on behaviour as identical (MZ) twins have the exact same DNA whereas fraternal (DZ) twins have the same as any other sibling. This way, we can study genetic and environmental influences on behaviour.
70
What was one of the most famous studies conducted?
Gottesmann and Shields (1966)
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What are the differences between MZ and DZ twins?
MZ come from one fertilised egg separated at a later stage whereas DZ twins come from two separate fertilised eggs.
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What are some difficulties when using MZ twins?
They don't occupy the exact same environment, even within the womb (different development) and can have slightly different physical attributes such as fingerprint. Some of their genetics could be environmentally induced - change over time despite the same DNA.
73
Define epigenetic modification
how environmental influences can turn genes on and off - some have more different or similar traits over time
74
How do twin studies compare both twins' sets' of data?
Analyse differences displayed with certain characteristics: strong differences means it has a genetic base and vice versa. If there is no differences between data sets, then it is known as a concordance rate (including IQ, anorexia, schizophrenia, alcoholism, depression and personality)
75
What are the strengths of twin studies? (2)
Born at the same time, with similar environments with only a genetic difference (MZ have a near 100% genetic similarity)
Both are treated as twins with no differences
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What are the weaknesses of twin studies? (2)
MZ may be treated more like twins than DZ due to physical similarity
Epi-genetic modifications need to be acknowledged from conception - always will have slightly differences (No study found a MZ 100% characteristic - environment always plays a role)
77
What are the aims of LaCourse et al (2014) twin study? (3)
Tests all three models
Gain insights into the genetics and environmental issues underlying aggression from infancy to school age
Use twins to show differences as it's easier to get acknowledgement and less bias
78
What are some of the general information of LaCourse (2014) twin study? (5)
Test was based on three models: Their own responsibility (both factors present in both intervals), Single Genetic Factor Responsibility (stronger genetic links to the model), New Influences (start with a weaker genetic influences that gains strength throughout)
254 MZ and 413 DZ twins were used (210 DZ same-sex twins) born between 1995 and 1998 in Canada
Sample not chosen by LaCourse
Focused on physical aggression via the mom's report at 20, 32 and 50 months old
Longitudinal study (Quebec Newborn Twin Study) with a shared and non-shared environmental factor - they obtained all genetic and environmental factors beforehand
79
What is the procedure for LaCourse (2014) twin study?
Genetic influence based on 100% MZ and 50% DZ twins
Differentiation = difference between genetics and environment as well as genetic contribution
Physical appearance taken by Quebec at 19.6, 31,9 and 50.2 months old - some didn’t have physical aggression data and soused the 588 twin pair where at least one twin had the data required
Physical aggression measured using a questionnaire with 3 items:
How much the child hits, kicks, punches, fights, attacks from a scale of 0-2 (never/ sometimes/ often)
Analysis of results was using the Pearson Correlational Statistical Test to find out the relationship between aggression and age
80
What were the results of LaCourse (2014) study? (3)
Steady growth with early aggression levels as predicted
Was a statistical significance between MZ / DZ data
All intervals did contribute to the shared environment
81
What conclusions were drawn from LaCourse (2014) twin study? (4)
Increase individual differences from 20 -50 months: Genetic maturation occurs
Genetic factors did contribute but their contribution declined over time
New genetic variables meant there was an innovation effect
Genetics was ½ the variant aggression
82
What were the strengths of LaCourse’s 2014 study? (3)
Repeated measures with no individual differences affecting all 3 measures
Thorough analysis with more than one process
Large sample size
83
What were the weaknesses of LaCourse’s 2014 study? (3)
Physical aggression measurement – should have gotten from more than one source
Unfair assumption of shared environment between twins
Twinetic socialisation differs from normal children – may lead to unfair generalisations
84
Why are adoption studies a thing?
Due to the nature of difference between the adoptive and biological environments despite having some genetics in common
85
In what situation is an adoption study helpful?
If studying genes linked to schizophrenia, researchers may wish to find out if offspring may also contract the same illness than those without family history of said illness however kids have to sets of genes and common environment therefore need all possible environments included within the study, in order to have the environment as a control variable.
86
What are the strengths of adoption studies? (2)
Way of separating genetics from environment whilst keeping genetic links (comparisons with biological parents) and a controlled environment (different than biological so can be certain is a genetic cause)
Study developmental trends through longitudinal studies to find genetic influences
87
What are the weaknesses of adoption studies? (2)
All adoptive families likely have same environment (approval from Children’s Services) and thereby not unique
Birth and Adoptive families may be similar
88
What is another type of adoption study?
Looking at MZ twins reared apart for a clearer genetic claim - way of controlling environment as MZ twins have 100% same DNA
89
What are the strengths of studying MZ twins reared apart? (2)
Controlled environmental conditions – similarities are solely due to genetics
Unique method for genetic differences – adoptive studies don’t carry same effect (not 100% same DNA)
90
What are the weaknesses of studying MZ twins reared apart? (3)
Not a large number due to insufficient data (unwilling families)
Not 100% different environments – until the second half of the 20th century, grandmother would raise the child as “mom” whilst biological acted as “sister”; with twins, one would have gone to an aunt thereby still sharing the same family and even school environment
Unclear if MZ / DZ twins and are rejected – lower sample sizes
91
What was the background for Leve et al (2010) study? (3)
Focused on genes and the environment with the influence of inherited characteristics on adoptive parents towards their children
Adoption = natural experiment with assumed genetic influences (similarities between the birth and adoptive environments) however genes were separated from the environment and assumed environmental influence in terms of the adoptive parents and children’s behaviour
Early Growth and Developmental Study (EGDS) is an adoptive study
92
What were the aims of Leve’s 2010 study?
```
Environmental moderation (genetics)
Family relationships and features affecting genetic influence from infancy in terms of gene manifestation from birth - in terms of environmental influences, problematic areas of upbringing (genetically or environmentally controlled)
Environmental issues: parenting and family guidance (genetic influence?), the externalisation or internalisation of problems, behaviour and school performance
Where genetics and environmental factors interact with the adoptive family: is child sensitive to familial environments (genetics?)? or evokes change?
```
93
What is the procedure for Leve’s 2010 study? (12)
Used the ‘adoptive triad’ with 360 linked sets of participants of both adoptive and biological parents with the child in order to effectively see all possible outcomes
The sample was 360 adoptive parents, 360 adoptive children, 359 biological males and 114 biological females (did do some further recruitment in 2003-2006 but the main focus was on the 360)
2% of biological males, 17% of adoptive females and 18% of biological females opted out of the study
Sample of children was, through 33 adoption agencies in 10 states, dependant on whether the baby was adopted within three months of birth with no major medical conditions
Phase 1 was done by EGDS in the toddler and infancy stage
Study looked at Phase 2 (school entry period), measuring executive function (could foretell externalising problems), literacy skills (foretell school performance) and cortisol reactivity (foretell internalisation of problems)
Assessments (frequent) were done by questionnaire and interviews (by phone and in real life), also used teacher and school data collections
Telephone interviews were in between real-life assessments to build rapport and aid retention, check on parenting wellbeing and daily behaviour (adoptive have questionnaires before their interviews), child temperament, interaction and standardised tests
In person assessments were at convenience (home) talking about intelligence, anti-social personalities and conduct, as well as functioning questions. Allowed for DNA collection – genes associated with anti-social behaviour lead to depression, anxiety and attention problems
Questionnaires were about behaviour and peer relations
Observation, standardised teaching and salivary cortisol collection (30 mins before and after sleep for 3 weekdays – collected by self and sent to team)
Reading was measured at 72 and 84 months
94
What results were concluded from Leve’s 2010 study? (4)
Bias from openness (confused with environment) and selective placements using correlations - affected environmental factors – had though openness was a significant problem as neither has significant impact on the results
Genes and Environment Interaction had many findings: complexity of interactions, attention level and frustration lead to a link to externalisation of problems, the environment can decide whether genes manifest (ie. Externalisation is an environmental factor and a genetic risk)
Adoptive mothers had impact on child’s emotions, rather than the adoptive fathers’ – could be due to their level of involvement with the child
Generalisability (Samples) is possible and is representative with no significant demographic differences
95
What were the strengths of Leve’s 2010 study? (2)
Size and representative sample (no generalizability issue)
| Data gathered through various methods – used triangulation to check reliability
96
What were the weaknesses of Leve’s 2010 study? (2)
Cause and effect hard to determine between variables
| Inference about genetic influence isn’t the same as looking at genes and phenotypes – limited child profiles
