Evolutionary & Genetic Influences on Aggression

Question 1

what is a widely accepted theory about the existence of humanity on Earth?

Answer 1

that we evolved to this stage through our ancestor’s need for survival

Question 2

what makes us who we are?

Answer 2

genes which are passed on through reproduction, with mutations

Question 3

what is evolution used for?

Answer 3

help scientists explain inherited characteristics

Question 4

how does evolution help scientists explain inherited characteristics?

Answer 4

In organisms, (sometimes right down to the DNA level), some inherited characteristic differentiation can help based on their region

Question 5

how can inherited characteristics be positive?

Answer 5

survival of the species

Question 6

how can inherited characteristics be negative?

Answer 6

extinction

Question 7

how did people pre=darwin try to explain the existence of humanity through science?

Answer 7

many notes the evolution of the species but put it down to different reasons e.g. degeneration of one species into another or organism modification down to the cellular level during reproduction

Question 8

what did Lamarck and others think about the evolution of humanity?

Answer 8

Lamarck thought parent’s chose their children’s characteristics for the children to become more environmentally suited.

Some thought evolution is impossible and the species were not related

Question 9

why did any of the alternate theories become known pre-darwin?

Answer 9

lack of hard evidence to gain the backing of the scientific community

Question 10

how did Darwin get his ideas about the survival of the fittest?

Answer 10

he considered the idea that not all of an organism’s traits survived in a particular environment or even during reproduction - the focus on specific traits led to the survival of the species and therefore must reproduction be the start and the end of the process

Question 11

did anyone have similar theories to Darwin at the time when he began to figure out ‘survival of the fittest’?

Answer 11

Wallace in 1858 send Darwin nearly the same idea, though both presented them differently

Question 12

what is natural selection?

Answer 12

the way some characteristics are better suited to a certain environment than others

Question 13

what are the important points of the natural selection process?

Answer 13

organisms have more offspring than required

some characteristics aid survival

characteristics are inherited

Question 14

what is the explanation behind natural selection?

Answer 14

characteristics aid the organism’s survival chance and therefore the organism’s reproduction, meaning that the trait will become more common later on.

Ill aiding traits would die out as the organism, most likely, will not be able to get to reproduction age.

In this way, our current inherited characteristics are what helped our ancestors survive and reproduce e.g. finches have their small beak due to the environment in which they live and the food they eat

Question 15

how else can organisms have inherited characteristics?

Answer 15

genetic mutation which can change species or lead to new ones

genetic drift - the random chances in passed out genes

Question 16

why does the explanation of natural selection only work if there’s variance?

Answer 16

it allows genes to be categorised. it comes from mutations e.g. genetic drift, but there is only a small amount of this

Question 17

why is there only a small amount of variance?

Answer 17

many organisms share most of the same characteristics e.g. fight or flight - little differences in genetic make-up lead to big differences in species

Question 18

what is the appearance of genetic mutations?

Answer 18

they can be visible, have no obvious effect or prevent proper gene function

Question 19

how is genetic mutation not beneficial?

Answer 19

prevent gene functions which is why there is a DNA mechanism that is present in the organism which could also lead to mutations

Question 20

how is genetic mutation beneficial?

Answer 20

can lead to mutations of large sections of DNA which could be beneficial - external sources e.g. carcinogens for cancer

Question 21

how does genetic mutation work in the context of natural selection?

Answer 21

only advantageous mutations will change the genetic pool as they’re the ones who’d survive until reproduction age

Question 22

why is genetic mutation only applicable to an extent?

Answer 22

survival of the fittest is dependant on genetic mutations but origin genes could also aid survival to their ‘fit’ characteristics

Question 23

what is genetic drift?

Answer 23

a reference to today - 100% of an offspring’s genes is 50/50 from either parent

Question 24

why is genetic drift considered to be a minor process in evolution (Fisher 1930)?

Answer 24

there is an element of chance which means some genes may be lost: this reduces genetic variation within the gene pool, narrowing it down

Question 25

Can genetic drift be seen as a factor in many genetic changes?

Answer 25

Kimura (1968) thought it has an important role to play in evolution and the factor to many genetic changes

Question 26

are all of our characteristics inheritable?

Answer 26

not all of them as these mostly come from the environment.

Many come from both genetics and the environment e.g. height

Question 27

define direct fitness

Answer 27

individual’s genes are passed on when it survives long enough to reproduce

Question 28

define inclusive fitness

Answer 28

individual’s genes are passed on through the relatives who survive long enough to reproduce

Question 29

what is the theory of evolution based on?

Answer 29

the idea that some advantageous characteristics are passed on from parents to offspring through reproduction

Question 30

how can natural selection be criticised?

Answer 30

on the basis of animal observations who also use altruistic behaviours e.g. animals calling out to warn of danger despite the risks this poses to their own lives. This type of risk contradicts natural selection, in that a group is more important than the individual such as meerkats

Question 31

what are some examples of altruistic animals?

Answer 31

vampire bats, ground squirrels and prairie dogs

Question 32

how can one negate the criticism of natural selection?

Answer 32

can claim it doesn’t go against natural selection as the animals warned are most likely relatives of the one ‘on the lookout’ and so genes of the individual can still be passed on through the offspring saved by the warning known as kin selection theory

Question 33

how is natural selection explained in the context of natural selection?

Answer 33

is genes adapting to survive the environment, rather than surviving through a single individual. In this way, disadvantageous genes may prove to be adaptive: the closer an animal is to those around it (through genetics), the more beneficial it is for that animal to use self-sacrificing behaviour, in terms of genetics

Question 34

what is direct fitness?

Answer 34

behaviour that protects the group thereby benefits the individuals within it as they might not survive otherwise

genes predispose them to be social as groups offer protection from predators or the stress of the protection of resources

Question 35

Why does ‘Wilson’ advocate for the group selection theory?

Answer 35

the entire idea is that a group will take care of the offspring as there will be a multi-generational society with some divisions in labour. As a community, they can cover all necessary works that are required. The success of living in a group leads to the survival of genes which promote group cooperation behaviour.

Question 36

what are some examples of ‘eu social’ behaviour within the group selection theory?

Answer 36

ants and bees

Question 37

what is interesting to note about eusocial animals which goes against natural selection?

Answer 37

not all eu-social organisms ‘evolved’ to be unable to reproduce, as this isn’t their function within the community, however their roles are passed on through behavioural traits within genetics. In a way, this can be seen to go against natural selection as it means that only reproductive organisms within the colony carry behavioural traits for all roles performed by those who cannot reproduce i.e. worker bees

Question 38

What are the strengths of the natural selection theory of human creation?

Answer 38

time resistant evidence such as Darwin’s Beagle Voyage and finch evidence; 1930s Kettlewell found more camouflaged moths lived until reproduction age than non camouflaged moths, suggesting inherited genes to be possible through reproduction

Darwin’s method was a good scientific method, and so can credibly reduce behaviour to genes so the focus can be on the genotype as well as allow for careful observation and evidence. → Learned and inherited characteristics can be observed

Question 39

What are the weaknesses of natural selection?

Answer 39

With reductionism, you cannot get an idea of the whole picture: Behaviour can be learned through observation and association. They didn’t consider all behaviours (such as kin selection theory) but you can state that he didn’t claim it covered everything

Wanted to confirm his theory rather than falsify it: to falsify something usually leads to evidence to prove the theory - Can only disprove theories by finding a piece of contradictory evidence

Creationism: beliefs are just as important as science - Can argue that natural selection has good scientific evidence

Question 40

why did humans evolve to have emotions?

Answer 40

helped aim survival e.g. living peacefully enables better chances of survival as it is easier to fight off predators and live a longer lifespan

Question 41

how can aggression aid survival?

Answer 41

Aggression may aid survival in order to protect their resources, their mates, as well as their offspring: this may have been an unplanned benefit to this trait.

Question 42

how is aggression in terms of mates logical?

Answer 42

jealousy is an evolutionary trait as a male needs to reproduce with a female but another male may threaten this and therefore should be dealt with - the males use aggression to defend/guard their females

Question 43

How does Blass and Shackleton (1977) help strengthen the idea of jealousy as a evolutionary trait?

Answer 43

Blass and Shackleton (1977) gathered evidence to see male responses to their threatened relationships. They found the male tended to give into the female (debasement) and threatening other males (intersexual threats). Blass and Shackleton also looked at the maintenance of relationships: women threatened to leave and used phrases such as ‘he is taken’. This experiment does not explain the individual decision making process but current inherited behaviours present in both sexes

Question 44

How does Dobash and Dobash (1984) help strengthen the idea of jealousy as a evolutionary trait?

Answer 44

Dobash and Dobash (1984) found violence against women usually stemmed from sexual jealousy as this lead to the eventual aggression

Question 45

what are some alternative explanations for the evolvement of aggression in humans?

Answer 45

limited resources as those who defended their resources successfully for longer would have longer lifespans and be able to reproduce

Question 46

How does Lorenz (1966) strengthen the idea of defending resources to be a explanation for aggression?

Answer 46

Lorenz (1966) through aggression to be an evolved trait (especially with males) in order to fight over resources.

Question 47

why is it more likely for more aggressive humans to pass on their genes?

Answer 47

More aggressive humans would be seen as stronger and if they are also ‘higher up’ within the social hierarchy, it is more likely that they are able to pass on their genes.

Question 48

what are the strengths of the aggression-evolution argument?

Answer 48

can be used to explain aggression with evidence

Used scientific methods e.g. careful observations of visible behaviour

scientific credibility is given as this is a widely accepted theory and is considered to be an important theory

Question 49

what are the weaknesses of the aggression-evolution argument?

Answer 49

Aggressive individuals protect their offspring, and therefore their genes but put themselves at risk - aggression wastes energy and therefore resources which can be seen as counterproductive

Can be used as a criticism of other theories explaining behaviour e.g, The frustration-aggression theory by Dollard (1987): if aggression cannot be used as a result of frustration within a scenario, it is taken out on another as a means of a reliever

inflexible

Question 50

what is some important evidence to consider when thinking about the aggression-evolution argument?

Answer 50

Gomez et al. 2016; Allen et al. 2016; and Buss et al. 2000

Question 51

How is Gomez et al. 2016 important to the aggression-evolution argument?

Answer 51

Gomez et al. (2016) found that humans, compared with other species, are unusually aggressive - they kill each other much more often than other species. This may suggest that the human species evolved aggression as an adaptive behavioural trait

Question 52

How is Allen et al. 2016 important to the aggression -evolution argument?

Answer 52

Allen et al. (2016) found that, over long periods of history, violence between humans becomes more common when times are hard (e.g. famine and drought). This supports the view that human aggression evolved as a way of securing resources like food and water.

Question 53

How is Buss et al. 2000 important to the aggression-evolution argument?

Answer 53

Buss et al. (2000) found that male violence towards their intimate partner is associated with a fear of infidelity. This is consistent with the idea that human aggression evolved to ensure that males only invested their resources (e.g. food, protection) into their own offspring, rather than another man’s

Question 54

what research methods are used within the aggression-evolution argument?

Answer 54

It is important to note that observational and correlational methods are usually used to study evolutionary influences. This includes making comparisons between different species i.e. scientists make comparisons between human behaviour and ape behaviour to try and find similarities and differences.

Question 55

what is descent with modification?

Answer 55

the idea that children and parents are slightly different to each other due to random modification

Question 56

what is common descent?

Answer 56

all things have a common ancestor and changed with descent with modification

Question 57

define aggression

Answer 57

behaviour intended to harm others (whether physical or psychological, and whether harm is actually caused or not).

Question 58

define hostile aggression

Answer 58

aggression where the aim is to hurt the target.

Question 59

define instrumental aggression

Answer 59

aggression that is used to achieve another aim.

Question 60

define species

Answer 60

a group of organisms that are sufficiently similar genetically to produce offspring through interbreeding.

Question 61

define evolution

Answer 61

the gradual change in the characteristics of a species over time

Question 62

define adaption

Answer 62

the process by which a species evolves to match the demands of its environment

Question 63

define gene

Answer 63

a sequence of DNA that codes for a particular characteristic in an organism

Question 64

define allele

Answer 64

a gene that can exist in two or more ‘versions’ which give rise to variations in a particular characteristic (e.g. coding for brown or blue eyes).

Question 65

define natural selection

Answer 65

an evolutionary process whereby adaptation occurs when individuals with traits that ‘fit’ the environment survive and reproduce more frequently than individuals with less ‘fit’ traits.

Question 66

How could a high level of openness be adaptive?

Answer 66

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

Question 67

How could a high level of openness be maladaptive?

Answer 67

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)

Question 68

How can a high level of conscientiousness be adaptive?

Answer 68

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

Question 69

How can a high level of conscientiousness be maladaptive?

Answer 69

refraining from impulsive behaviour and actions could put individuals in danger as that lifestyle relied heavily on spontaneous reactions.
Poor prioritising

Question 70

How could a high level of extraversion be adaptive?

Answer 70

A high extraversion is adaptive as people with high extraversion are outgoing and sociable so it will be easier for them to join a clan and find a mate.
Also, people who are highly extraverted get bored easily and in this environment there would constantly be things that needed doing - hunting, cooking, raising children etc. so it wouldn’t get boring for them

Question 71

How could a high level of extraversion be maladaptive?

Answer 71

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.

Question 72

How could a high level of agreeableness be adaptive?

Answer 72

A high level of agreeableness suggests that the person would be friendly and probably well liked by others so if they were in need, they would be more likely to be helped. 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.
Being likeable and friendly means they would find it easier to find a mate.

A high level of agreeableness means they would be more cooperative and because they used to travel in groups they would have to work with each other in order to survive therefore this is adaptive.

Question 73

How could a high level of agreeableness be maladaptive?

Answer 73

Individuals could have trusted the wrong person and that person could have taken advantage of this 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.

Question 74

How could a high level of neuroticism be adaptive?

Answer 74

Could keep the person safe due to the lack of trust that could possibly come with this trait (threat )
May make a person less likely to take careless risks so keeping them out of danger

Question 75

How could a high level of neuroticism be maladaptive?

Answer 75

Higher risk of anxiety,depression and anger which may cause problems within groups or ‘tribes’,may also decrease their time of survival due to these emotions being overwhelming especially in their ‘nordic’ and ‘hunter gatherer’ lifestyle.

Question 76

what is used to study genetic influences on behaviour?

Answer 76

twin studies

Question 77

why are twin studies used to study the influence of genes on aggression?

Answer 77

Although genes make up our bodies, our behaviour can also be influenced by the environment as well as genetics. As identical twins have the same genetic data (more so than non-identical twins), when examining a particular characteristic, it’s easier to see the genetic influence.

Question 78

what possible problems are there with the concept of twin studies?

Answer 78

most twins share the same environment, making genetic influences harder to ascertain therefore twin adoption studies are crucial as both are brought up in different environments

Question 79

what is one of the most famous twin studies?

Answer 79

Gottesman and Shield (1966)

Question 80

define epigenetic modification

Answer 80

how environmental influences can turn genes on and off: how some tend to display different traits over time, but some become more similar i.e. in terms of IQ or personality.

Question 81

what are monozygotic twins?

Answer 81

Identical twins (monozygotic MZ) come from one fertilised egg which is separated at a later stage so these twins carry the exact same genetics

Question 82

do MZ twins share the same environment?

Answer 82

However MZ twins don’t occupy the exact same environment even in the womb, so they tend to develop differently: this could be why they do have some slightly different physical traits i.e. fingerprints. Some of their genetics may also be environmentally induced, so they become different over time, despite having the exact same DNA.

Question 83

what are dizygotic twins?

Answer 83

Non-identical twins (dizygotic twins DZ) come from two separately fertilised eggs, meaning they don’t share the exact same replication of data and so are only as alike as every other sibling is, to a certain extent: they only share the same womb.

Question 84

how do twin studies use MZ and DZ twins?

Answer 84

Twin studies compare both sets of twins to analyse the differences displayed on certain characteristics. If there is said to be a strong difference, then that characteristic has a basis in genetics and vice versa. When both sets of twins share the same characteristics, it’s known as a concordance rate

Question 85

what are some examples of concordance rate characteristics?

Answer 85

IQ, anorexia, schizophrenia, alcoholism, depression and personality.

Question 86

what are the strengths of twin studies?

Answer 86

Both sets of twins are born at the same time with similar environments → the only difference is that MZ twins have an exact replication of data, which is the main way scientists can study the genetic effect on behaviour
Both are treated as twins (similar environment) and so there should, theoretically be no differences in this respect.

Question 87

what are the weaknesses of twin studies?

Answer 87

MZ twins may be treated more like twins than DZ twins, as they look physically similar,
Epigenetic modification has to be taken into account from conception → there will always be slight differences in environment: No study has found a characteristic that is 100% MZ twins - environment always plays a factor.

Question 88

What were the aims of Lacourse et al. (2014) twin study?

Answer 88

To look at genetic and environmental issues underlying the development of physical aggression from infancy to when the child is school age

To use twins to look at genetic and environmental factors to explain the change in physical aggression in individuals from infancy to 50 months

Question 89

What were the participants like for Lacourse et al.’s 2014 twin study?

Answer 89

The twins were born between 1995 and 1998 in Canada.

All parents of the twins born were invited to take part in the Quebec Newborn Twin Study.

In total, there are 254 MZ twins and 413 DZ twins (210 of the DZ twins were same-sex pairs).

Information about their physical aggression was collected by the Quebec Newborn Twin Study at around 19.6 months, 31.9 months and 50.2 months.

Question 90

What was the procedure like for Lacourse et al.’s 2014 twin study?

Answer 90

Using MZ and DZ twins, they looked at shared environment and non-shared environment → this was to get the genetic factors and environmental factors into their study.

Physical aggression was measured as part of a questionnaire given to mothers: The measure was how many times a child hits, bites, kicks (1st item); a child fights (2nd item); one attacks another (3rd item). The mothers answered ‘never (0), sometimes (1), often (2)’ for each item.

The analysis of genetic influences was done through a correlational statistical test (Pearsons), to look at the relationship between age and aggression score. It was based on MZ twins sharing 100% of their genes and DZ twins sharing 50%: From knowing whether they were MZ or DZ twins, this can show information for genes and environment can be looked at. The differences between MZ and DZ twins can show the genetic contribution.

Question 91

What are the findings of Lacourse et al.’s 2014 twin study?

Answer 91

The study measured the differences in scores between MZ and DZ twins at each age: The MZ twin pairs were more likely to both show the same scores for physical aggression than DZ twin pairs.

At 20 months - mean P.A 1.82 (1.49)
At 32 months - Mean P.A. 2.19 (1.46)
At 50 months - Mean P.A.
2.24 (1.50)

The rising slope in physical aggression showed MZ and DZ differences.

As MZ twins are found to be more similar than DZ twins both in their physical aggression scores and in the way they rise between the three age periods, this is taken as evidence that the genes contribute to physical aggression

Genetic, non-shared environment and shared environment differences were also looked at between MZ and DZ twins. It was found that both genes and non-shared environment contributed to the physical aggression levels.

Genetic factors were associated with physical aggression at all 3 ages

Question 92

What were the conclusions of Lacourse et al.’s 2014 twin study?

Answer 92

The early onset of physical aggression was explained by genetic factors and these declined over time

New genetic factors at each age contributed to physical aggression levels at each of the ages

They found an increase in frequency of physical aggression from 20 months to 50 months, though the speed of the increase did slow over time

Individual differences in physical aggression were large

Genetic factors always accounted for differences in physical aggression at 20 months (60% of the variance), 30 months (60% of the variance) and 50 months (50% of the variance)

Question 93

What are the strengths in generalisability in Lacourse et al.’s 2014 twin study?

Answer 93

The size of the sample and the access to both MZ and DZ twins have a lot of information → If there are any inaccuracies or anomalies in the sample, the large number should be able to take care of this.

Question 94

What are the weaknesses in generalisability for Lacourse et al.’s 2014 study?

Answer 94

Twins may differ from non-twins,in that there is socialisation between them that may not be present in single-birth children. Generalising from twin studies to state that these findings are generalisable to all children.

Question 95

What are the strengths in validity for Lacourse et al.’s 2014 study?

Answer 95

The analysis is thorough, using more than one process: the study uses a Cholesky decomposition and latent growth curve.

This is a repeated measures design, which means that the same child is measured at three different ages so that development trends are measured and compared → this means that there are no individual differences that will affect the same child, thrice.

Question 96

What are the weaknesses of validity for Lacourse et al.’s 2014 study?

Answer 96

Only the mother contributed to the data → One mother may emphasise the similarities in the family, which could lead to more emphasis being placed on the shared environment, when this may not actually be the case. It would be better if the data was gathered from more than one person and in more than one place to help strengthen its internal validity

Question 97

Why are adoption studies a thing?

Answer 97

They are carried out due to the nature of differences between biological and adoptive environments

Question 98

Give an example where adoption studies would be a good thing

Answer 98

Detecting whether an individual is more susceptible to contract a particular mental illness e.g. schizophrenia

If a gene relating to schizophrenia is being studied, researchers may wish to find out if a schizophrenia patient’s child would also contract the illness than those without a family history however kids usually have two sets of genes and a common environment therefore, if children with and without schizophrenia as well as adopted children, the environment is controlled.

Question 99

what are the strengths of adoption studies?

Answer 99

A way of separating genetics from their environment, they keep the genetic link (comparisons with biological parents), control for the environment (different environment away from biological) → removes possible influences so researchers can be certain that genes are the cause.

Can study developmental trends → longitudinal studies which can be used to find genetic influences

Environmental conditions are controlled

Unique research method controlling for genetic differences

Question 100

What are the weaknesses of adoption studies?

Answer 100

All adopted families are likely to be the same (have to be approved) thereby making the child’s environment somewhat unique.

Birth and adoptive families may be similar.

No large numbers to draw from

This may not be true, as up until the 2nd half of the twentieth century, when a unmarried young girl gave birth, their family would be the ones who reared the child so their environment would be shared and the theory behind the research method would have been lost

Twins can be excluded as it is not certain whether they are MZ or DZ so mistakes can be made

Question 101

Why would someone study MZ twins reared apart?

Answer 101

This is a way of controlling that characteristics have a genetic basis, and the environment would be completely different for each twin. If they were reared together, a shared environment may have caused the characteristics, rather than genetics.

Question 102

What did Bergeman et al. 1998 find in their MZ twins reared apart study?

Answer 102

Bergeman et al. (1998) carried out a study of identical twins with non-shared environments (separated all throughout their lives) and covered two characteristics: their personality traits and their impulsivity. The findings showed the way the environment affects individuals depends on their genetic make-up as well as the type of environment they were in. It is a mix of nature and nurture.

Question 103

What were the aims of Leve et al. 2010’s adoption study generally?

Answer 103

To look family relationships and the features in such relationships that affect genetic influences from infancy and find out what influences a genetic trait to manifest into an individual’s behaviour

Question 104

What were Leve et al. 2010’s aims broken down?

Answer 104

A1: To look at specific environmental issues relating to parenting and family processes that mediate (interact with) genetic factors on a child

A2: To look at specific environmental issues relating to parenting and family processes, with a focus on how the environment might moderate genetic behaviour

A3: To look at adopted child and adoptive parent to see how, when and why genes and environment interactions occur between them

Question 105

What were the participants like for Leve et al. 2010’s adoption study?

Answer 105

360 linked sets of adoptive triads recruited from 2003-2006 from at first recruiting (33 in ten states) adoption agencies, and then an adoption liaison from each agency to recruit the adoptive triads.

Each child had to be adopted within 3 months of birth in order to be accepted, with other conditions such as no known medical conditions, being necessary for acceptance.

360 adoptive parents, 360 adopted children (43% female), 359 birth mothers and 114 birth fathers.

Question 106

What was method like for Leve et al. 2010’s adoption study?

Answer 106

The study used an ‘adoptive triad’ which is the birth parents, the adoptive parents and the adopted child, so that they could see which genetic/ environmental influences affected each other and possibly how.

Question 107

What was Leve et al. interested to know about in his 2010 study?

Answer 107

He was interested in the second phase of the experiment, assessing the participants in the school entry periods as the infancy & toddler assessments had already taken place in other published studies within the EGDS.

Question 108

How was recruitment approached within Leve et al. 2010’s study?

Answer 108

Recruitment was a means of ‘opt-out’, with the birth mother being recruited first, and if agreed, then they approached the adoptive family. If they agreed, then they approached the biological father → once recruited, many did not decline to take part (2% of birth mothers, 17% of adoptive families and 8% of birth fathers); drop-out was usually as they could be found. Different staff members dealt with adoptive parents, birth mother and father in order to retain confidentiality.

Question 109

What did Leve et al.’s 2010 adoption study measure?

Answer 109

It measured executive function (a measure that can foretell externalising problems), early literacy skills (a measure that can foretell school performance), and cortisol reactivity (linked to internalising problems).

Question 110

How were people assessed in Leve et al.’s 2010 adoption study?

Answer 110

Assessment was done frequently, through:

Questionnaire and interviews for birth and adoptive parents

Observation for adoptive families

Standardised testing for both sets of parents and children

Salivary cortisol for birth parents and adoptive children

Salivary DNA for all participants.

Question 111

How were in person assessments conducted in Leve et al.’s 2010 adoption study?

Answer 111

In person assessments were done when convenient for the birth parents, involving interviews and questionnaires (including intelligence questions, antisocial personality and conduct disorder and functioning questions). For adoptive parents, this was done at home, with questionnaires completed before the interview, but they also had child-temperament tasks, parent-child interaction tasks and standardised tests

Question 112

How were telephone interviews conducted in Leve et al.’s 2010 adoption study?

Answer 112

Telephone interviews took place between the in-person assessments to help with building rapport, and aid retention → mostly about well-being and child’s daily behaviour as well as parenting

Question 113

How was cortisol collected for Leve et al.’s 2010 study?

Answer 113

Cortisol collected 30 minutes after waking up and before going to sleep, on 3 weekdays (6 in total), with participants taking their own samples after being shown how to do so and posted in a pre-paid envelope to the research team.

Question 114

Did anyone else complete data for Leve et al.’s 2010 adoption study?

Answer 114

Pre-school, nursery and school teachers completed questionnaires about child behaviour and peer relations using a website at 72 and 84 months.

Question 115

How was DNA collected for Leve et al.’s 2010 adoption study?

Answer 115

DNA Collection was during one of the at-home interviews so they could look at the genes associated with anti-social behaviour, depression, anxiety and attention problems.

Question 116

What did the findings of Leve et al. 2010 find in terms of sampling?

Answer 116

Found their sample to be representative and tested this to make sure. There were no significant differences in demographic and therefore concluded that generalisation of findings throughout the USA is possible.

Question 117

What did the findings of Leve et al. 2010 find in terms of adoptive placements?

Answer 117

If adoption placements include selective placements, then the idea that a child inherits genes from their birth parents and their environment from their adoptive parents is flawed. Openness can be a problem as this deals with contact between birth and adoptive parents, which produces a confounding variable. They used correlations to check out characteristics that may come from selective placements and found no effects; they also correlated the number of times of meeting between birth and adoptive families which found no statistical significance.

Question 118

What did the findings of Leve et al. 2010 find in terms of behaviour of birth parents?

Answer 118

Found that externalising behaviour of birth mothers could show a genetic risk for externalising problems and adoptive parents’ level of anxiety or depression could be an environmental issue that was associated with the child being unable to shift attention from a frustrating task or event.
This shows that a genetic issue around externalising behaviour and attention remaining on frustrated tasks is affected by the environment.

Question 119

What did Leve et al. 2010 conclude from his adoption study?

Answer 119

Genetic factors within an adoptive environment can interact with the environmental influences within the adoptive family to produce behaviour. If such things are known about beforehand, there can be a possible intervention to help alleviate the issue e.g. it would be helpful to know if an adoptive child whose focus is on frustrating events rather than moving on, making them more likely to exhibit aggressive behaviours, having the presence of their adoptive mother who is depressed/anxious would most likely alleviate/aggravate that behaviour than an adoptive mother without these disorders.

Question 120

What are the strengths of generalisability of Leve et al. 2010 (adoption study)?

Answer 120

Size of sample and focus on it being representative

Question 121

What are the weaknesses of generalisability of Leve et al. 2010 (adoption study)?

Answer 121

Participants who take part in these studies are gathered using volunteer samples. This introduces an element of bias in the sampling and may therefore not be generalisable.

Children tend to be placed in families like their own, meaning the adoptive and biological environments are likely to be similar.

It is likely that only certain types of family are accepted as adoption parents, so they are all likely to be similar to one another.

Question 122

What are the strengths of reliability of Leve et al. 2010?

Answer 122

Used a variety of methods to gather data, so they could use triangulation to check the reliability of said data e.g. collected cortisol samples six times and had questionnaire data before they conducted the interview so they could cross-reference

Question 123

What are the strengths of objectivity of Leve et al. 2010?

Answer 123

The longitudinal approach means that the same group of children are studied so trends can easily be noted. Trends can then be linked to genetic influences.

Developmental trends can be studied as they are longitudinal studies. The same child/ group of children can be followed as they develop, so characteristics that come about as genes are triggered can be studied.

Question 124

What are the weaknesses of objectivity of Leve et al. (2010)?

Answer 124

Inferring genetic influence from looking at the birth mother and child similarities is not the same as using DNA to find the genotype - although the researchers intended to collect DNA samples, this was not done at the point of which the research was reported and the findings not evidenced so their conclusions about the adoptive child’s genetic profile was limited.

Question 125

What are the strengths of validity of Leve et al. (2010)?

Answer 125

Adoption studies are a way of separating genes from the environment. They keep the genetic link, as they compare the child with their biological families, but as they do not have a shared environment, and differences are likely to be caused by genes.

Question 126

What are the weaknesses of validity of Leve et al. 2010?

Answer 126

Children are rarely adopted immediately from birth so they may have spent time living with their biological parents so the environment may well play a part. This is a confounding variable.

Difficult to show cause-and-effect relationships between variables e.g. it’s hard to measure attention and frustration and later link this to aggressive behaviour

Question 127

What are some important studies about twin studies?

Answer 127

Brendgen et al. (2005); Coccaro et al. 1997

Question 128

Why is Brendgen et al. 2005 important to twin studies?

Answer 128

Brendgen et al. (2005) found that identical twins were more similar in aggression than non-identical twins. This shows that genes contribute to individual differences in aggression but Brendgen et al. also found that environmental influences outside the home also influence aggression levels

Question 129

What are some important studies about adoption studies?

Answer 129

Van den Oord et al. 1994; Schulsinger 1972; Mednick et al. 1987

Question 130

Why is Van den Oord et al. 1994 important to adoption studies?

Answer 130

van den Oord et al. (1994) found that adopted Dutch children aged 10-15 years were more similar in aggression to their biological than their adoptive siblings, suggesting that genes contribute to individual differences in aggression.

Question 131

What research methods are used for genetic influences on aggression?

Answer 131

Most of what we know about the influence of genes on behaviours like aggression has been learned using twin and adoption studies, which are based on correlational analysis

Question 132

why is Shulsinger (1972) important to adoption studies?

Answer 132

Shulsinger (1972) had an adoption study (57 adopted individuals diagnosed with psychopathy), and took measures of psychopathic traits from both the adoptive and biological parents. Psychopathic traits were found at a higher concentration (3.9%) in the biological parents in comparison to the adoptive parents (1.4%). However this difference is small enough to be considered to be statistically insignificant (due to chance) and so it cannot be reliably said to be a genetic influence. It is hard to draw conclusions about the wider population’s aggression from this study, as most aggressive people are not psychopaths

Question 133

why is Mednick et al. 1987 important to adoption studies?

Answer 133

Mednick et al. (1987) analysed 14,000 male adoptees, comparing the proband’s rates of criminal convictions with that of their adoptive and biological fathers. Results found the probands had a conviction (13.5%) when neither the biological and adoptive fathers had criminal convictions. If the biological father had a conviction, this rose to 20% and if this was an adoptive father’s conviction, it would rise to 14.7%, whilst if both had prior convictions, this rose to 24.5%. These suggest both environmental and genetic influences influence criminality, with genetics playing a larger role. This is consistent with previous data, but these individuals had prior convictions, making it harder to isolate genetic influences.

Question 134

Why is Coccaro et al. 1997 important to twin studies?

Answer 134

Coccaro et al. (1997) conducted a twin study (182 MZ & 118 DZ), in which all participants completed a self report measure that assessed direct,indirect, verbal and physical aggression, with researchers looking for correlations between all. MZ correlations (.50) were higher than DZ twins (.19). This correlates with the view that genetics contribute to aggression (both sets of twins have similar environments). He concluded about 40% of variability in children’s aggression is due to genetics.

Question 135

What were the aims of Brendgen et al. 2005?

Answer 135

To investigate whether social aggression could be caused by genes or the environment and whether social aggression shared the same cause as physical aggression

To investigate whether a correlation between physical and social aggression is due to genetics or social situation

To investigate whether one type of aggression leads to another

Question 136

What is the background of Brendgen et al. 2005?

Answer 136

It begins from the view that aggression in children is seen as a risk factor for later development, not only from being perpetrators of crime but also victims → understanding the cause is important to society

There are two types of aggression: ‘indirect’ aggression which is more subtle and covert e.g. spreading rumours and ‘direct’ aggression which is more overt, and often physical. ‘Social aggression’ uses both overt and covert methods, as well as non-verbal aggression e.g. pulling faces.

Brendgan et al. consider child aggression by studying parental aggressive behaviours as it is hard to determine the cause (genes or environment) by separating behaviours as they are intertwined however twin studies can be used to overcome this problem.

Question 137

What are the participants like for Brendgen et al. 2005?

Answer 137

Quebec Newborn Twin study from the Montreal area of Canada, recruited from birth from November 1995 - July 1998. There were 322 twin pairs, 237 same-sex twin pairs; with physical resemblance used to allocate them to the category of identical or non-identical twins.

123 twin pairs had DNA obtained to compare the results with the decision based on physical resemblance with a 94% agreement rate

Question 138

How did they gain data in Brendgen et al. 2005?

Answer 138

They used teacher/peer ratings to get information about social and physical aggression, as other studies have shown such data to have reliability and construct/predictive validity however they do not have good correspondence to one another - he wanted to see if teacher and peer ratings would give the same pattern of results in regards to the research question.

Question 139

How did they obtain peer data in Brendgen et al. 2005?

Answer 139

Peers asked to circle photographs in answer to instructions (after photographs were circulated to make sure peers knew the children) with the data giving each individual child a social and physical aggression score. There was internal consistency between individual scores from peers.

Question 140

How did they obtain teacher data in Brendgen et al. 2005?

Answer 140

The teachers completed behaviour questionnaires for the twins, rating social and physical aggression for each child based on standardised scales. For a child with different teachers, the scores given did agree with one another - reliable.

Question 141

What was the rest of the procedure like for Brendgen et al. 2005?

Answer 141

A comparison was made between the twins and single children in regards to parental education, yearly income, age of parents when the children were born and marital status with the general consensus being that the twins were not different in these aspects.

They used the data gathered from birth until the age of 6 at fairly regular intervals with 324 twin pairs at this stage: 44 identical (male), 50 identical (female), 32 non-identical (female) and 67 non-identical (mixed gender).

Written consent was obtained from parents of all the children in the classroom, and research questions and questionnaires approved by the Institutional Review Board. 409 classrooms were used, with peer data collected from sociometric data (who is friends with whom)

Question 142

What did they find generally in Brendgen et al. 2005?

Answer 142

According to teachers, boys were rated more physically aggressive than girls and girls more socially aggressive; but this was not borne out of the data and so no gender difference was found.

There was overlap between physical and social aggression scores in teacher and peer ratings although this link was ‘moderate’.

Statistically, data was measured using a chi-squared test and found a close match between teacher and peer ratings as with regards to gender, neither the overlap of social and physical aggression nor the amount of genetic and environmental contributions differed between boys and girls.

Question 143

What did they find in terms of the role of genes and the environment in Brendgen et al. 2005?

Answer 143

MZ correlation twice as high as same-sex DZ correlations (physical aggression) which shows a big contribution from genetic towards physical aggression
MZ and same-sex DZ have similar correlations towards social aggression, suggesting this characteristic to be more defined by shared environments rather than genetics

Question 144

What was the conclusions of Brendgen et al. 2005 in terms of differences in aggression?

Answer 144

50%-60% of differences in physical aggression is down to genes, in 6 year olds, with the rest being a result of the environment . For social aggression, only 20% of differences were down to genetics, 20% down to shared environments and 60% down to non-shared environments → Social aggression is more as a result of the environment, whereas physical aggression is more of a result of genetics.

Question 145

What was the conclusion for Brendgen et al. 2005 in terms of overlap between types of aggression?

Answer 145

There was a moderate overlap between social and physical aggression, with some being genetically disposed to behave aggressively or socially as a result of parental psychological control e.g. love withdrawal.

Brendgen et al. (2005) found the higher levels of physical aggression in an individual would result in a higher level of social aggression as the two types of aggression were connected; however, higher social aggression cannot predict higher physical aggression

Question 146

What were the strengths and weaknesses of generalisability in terms of Brendgen et al. 2005?

Answer 146

Small sample sizes, as although 409 classrooms were studied, a larger sample size was not psychologically feasible.

Only 6 years olds were used, and therefore generalising beyond this year is unfeasible

Question 147

What were the strengths and weaknesses in terms of validity of Brendgen et al. 2005?

Answer 147

Teacher and peer ratings are used which showed many similarities

Longitudinal studies are better in terms of genetic influences on behaviour as cross-sectional studies just show one moment in time, and developmental issues cannot be followed through

Ratings are not direct observations so there could be a lack of validity - there may also be stereotypes or better/worse recall

Question 148

define evolutionary psychology

Answer 148

the view that genes are a significant influence on thinking, emotions and behaviour and have been shaped by evolutionary processes.

Question 149

define mendelian trait

Answer 149

a characteristic that is influenced by a single gene (e.g. eye colour).

Question 150

define polygenetic trait

Answer 150

a characteristic that is influenced by many genes all acting together (e.g. skin colour). Most psychological traits (e.g. IQ, personality and aggression level) are polygenetic.

Question 151

define family history study

Answer 151

a method for estimating the size of a genetic influence by seeing whether a trait runs in families.

Question 152

define adoption study

Answer 152

• a method for estimating the size of a genetic influence by seeing whether adopted individuals are more similar to their biological or adoptive parents/siblings.

Question 153

define twin study

Answer 153

a method for estimating the size of a genetic influence by seeing whether identical twins are more similar than non-identical twins on a particular trait