Evolutionary & Genetic Influences on Aggression Flashcards

Question

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

Answer 1

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

Answer 2

not all of them as these mostly come from the environment. Many come from both genetics and the environment e.g. height

Answer 3

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

Answer 4

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

Answer 5

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

Answer 6

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

Answer 7

vampire bats, ground squirrels and prairie dogs

Answer 8

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

Answer 9

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

Answer 10

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

Answer 11

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.

Answer 12

ants and bees

Answer 13

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

Answer 14

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

Answer 15

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

Answer 16

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

Answer 17

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.

Answer 18

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

Answer 19

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

Answer 20

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

Answer 21

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

Answer 22

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

Answer 23

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.

Answer 24

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

Answer 25

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

Answer 26

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

Answer 27

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

Answer 28

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.

Answer 29

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

Answer 30

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.

Answer 31

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

Answer 32

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

Answer 33

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

Answer 34

aggression where the aim is to hurt the target.

Answer 35

aggression that is used to achieve another aim.

Answer 36

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

Answer 37

the gradual change in the characteristics of a species over time

Answer 38

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

Answer 39

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

Answer 40

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).

Answer 41

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.

Answer 42

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

Answer 43

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)

Answer 44

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

Answer 45

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

Answer 46

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

Answer 47

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.

Answer 48

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.

Answer 49

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.

Answer 50

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

Answer 51

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.

Answer 52

twin studies

Answer 53

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.

Answer 54

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

Answer 55

Gottesman and Shield (1966)

Answer 56

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.

Answer 57

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

Answer 58

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.

Answer 59

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.

Answer 60

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

Answer 61

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

Answer 62

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.

Answer 63

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.

Answer 64

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

Answer 65

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.

Answer 66

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.

Answer 67

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

Answer 68

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)

Answer 69

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.

Answer 70

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.

Answer 71

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.

Answer 72

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

Answer 73

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

Answer 74

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.

Answer 75

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

Answer 76

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

Answer 77

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.

Answer 78

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.

Answer 79

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

Answer 80

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

Answer 81

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.

Answer 82

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.

Answer 83

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.

Answer 84

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.

Answer 85

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).

Answer 86

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.

Answer 87

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

Answer 88

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

Answer 89

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.

Answer 90

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

Answer 91

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.

Answer 92

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.

Answer 93

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.

Answer 94

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.

Answer 95

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.

Answer 96

Size of sample and focus on it being representative

Answer 97

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.

Answer 98

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

Answer 99

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.

Answer 100

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.

Answer 101

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.

Answer 102

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

Answer 103

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

Answer 104

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

Answer 105

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

Answer 106

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.

Answer 107

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

Answer 108

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

Answer 109

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.

Answer 110

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.

Answer 111

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

Answer 112

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.

Answer 113

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

Answer 114

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.

Answer 115

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.

Answer 116

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.

Answer 117

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)

Answer 118

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.

Answer 119

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

Answer 120

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.

Answer 121

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

Answer 122

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

Answer 123

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

Answer 124

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

Answer 125

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

Answer 126

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.

Answer 127

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

Answer 128

- 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.

Answer 129

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

Evolutionary & Genetic Influences on Aggression Flashcards

(153 cards)