Module 4: Behavioural Genetics and Physiology

Question 1

Skin conductance can be a correlate for studying anxiety and neuroticism. Why?

Answer 1

Because skin conductance increases with elevated activity of the sympathetic nervous system

Question 2

EEG enables scientists to study brain activity with high temporal resolution. What does this mean?

Answer 2

Means that electrical activity produced by neutrons is picked up by electrodes as soon as they are produced

Question 3

What are the 3 major limitations of EEG?

Answer 3

1. Can only be used to study brain regions that are close to the scalp
2. Low spatial resolution (cannot tell where the source of the electrical activity is coming from)
3. Low signal to noise ration (data is spatially imprecise, picks up other data like muscle movements)

Question 4

Psychologists use fMRI to observe…

Answer 4

how presenting stimuli produce increased activity in different brain regions

Question 5

What reasons may explain the replication crisis in fMRI personality studies?

Answer 5

1. Situational influences may be more responsible for the variability in brain responses rather than personality differences
2. Individual differences in personality may not be visible in an experimental circumstance using an fMRI machine

Question 6

What is one of the central goals of genetic research?

Answer 6

To determine the percentage of an individual difference than can be attributed to genetic differences and the percentage due to environmental differences as well as how genes and environment interact

Question 7

Heritability

Answer 7

The proportion of observed variance in a group of individuals that can be accounted for by genetic variance

Question 8

Can heritability be applied to a single individual? Why or why not?

Answer 8

No it cannot.

Heritability refers only to differences in a sample or population not to an individual

Question 9

Is heritability constant? Why or why not?

Answer 9

No it is not.

Heritability applies only to a population at one point in time.

Question 10

Is heritability an absolute precise statistic?

Answer 10

No it is not.

Error or unreliability of measurement for example can distort heritability statistics. So, heritability is best regarded as an estimate.

Question 11

At the level of the individual is there a nature-nurture debate?

Answer 11

No.

Every individual contains a unique set of genes that require environments to produce a recognizable individual. Both genes and the environment are necessary and we cannot logically disentail them to see which is more important for one particular individual.

Question 12

What level of analysis (individual or population) do behavioural geneticists operate?

Answer 12

Population

This is the level we can disentangle the influence of genes and environments

Question 13

What 4 methods are used to disentangle the contributions of genes and environments as causes of individual differences?

Answer 13

1. Selective breeding with animals
2. Family studies
3. Twin studies
4. Adoption studies

Question 14

Results from family studies alone can never be definitive. Why?

Answer 14

Because family members who share the same genes, especially those with greater genetic relatedness, also typically share the same environment

Question 15

What is an important assumption of the twin method?

Answer 15

Equal environments assumption

Assumes that the environments experienced by identical twins are no more similar to each other than are the environments experienced by fraternal twins

Question 16

Adoption studies allow researchers to get around the equal environments assumption. However, there are 2 particular limitations of adoption studies:

Answer 16

1. Assumption of representativeness
   - assume that adopted children, their birth parents, and their adoptive parents are representative of the general population
2. Selective placement
   - if adopted children are placed with adoptive parents who are similar to their birth parents this may inflate the correlations between the adopted children and their adoptive parents
   - does not seem to be a problem though

Question 17

What are the 2 most commonly studied traits in behavioural genetic research?

Answer 17

Extraversion and neuroticism

Question 18

Summarizes of the behavioural genetic data for many of the major personality traits (extraversion, agreeableness, conscientiousness, neuroticism, and openness) yield heritability estimates of approx….

Answer 18

50 percent

Question 19

Some attitudes have been shown to demonstrate moderate heritability (i.e., conservative values) and some have not (i.e., belief in God). Why might this be the case according to a study by researchers from the University of Western and University of BC?

Answer 19

For some attitudes, it is the heritability of personality traits that actually mediated the heritability of related attitudes

Question 20

Drinking and smoking are often regarded as ________________ ________________ of personality dispositions such as sensation-seeking, extraversion, and neuroticism

Answer 20

behavioural manifestations

Question 21

Do genes influence the propensity to marry or not and do they play a role in marital satisfaction? Why or why not?

Answer 21

Yes they do. The heritability estimate is above 50%

This may work through certain personality characteristics

Question 22

The personality traits most consistently associated with nonspecific electrodermal responding are…

Answer 22

anxiety and neuroticism

Question 23

Some people show much larger increases in heart rate and blood pressure than others. This phenomenon has been called ___________ ___________ and has been associated with…

Answer 23

cardiac reactivity

Type A personality (i.e., impatience, competitiveness, hostility)

Question 24

One study using fMRI found that personality correlated with the degree of brain activation in response to the positive and negative images. What did they find?

Answer 24

Neuroticism correlated with increased frontal brain activation to negative images and extroversion correlated with increased frontal brain activation to positive images

Question 25

What hormone has been linked to uninhibited, aggressive, and risk-taking behaviour patterns.

Answer 25

Testosterone

Question 26

From biochemical analyses of saliva, researchers found that shy children have high levels of __________ in their systems suggesting that they experience more stress than less hay children.

Answer 26

cortisol

Question 27

From biochemical analyses of blood, _________ may be a causal factor in the personality trait of sensation seeking

Answer 27

MAO

Question 28

Extraversion-Introversion is a theory put forth by Eysenck which proposes that…

Answer 28

introverts are characterized by higher levels of activity in the brain’s ascending reticular activating system (ARAS) than are extraverts

Question 29

According to Eysenck’s extraversion-introversion theory, introverts have higher resting levels of _________ arousal because their ARAS lets in too much stimulation. Conversely extraverts need to increase their arousal.

Answer 29

corticol

Question 30

Explain how Eysenck incorporated Hebb’s notion of “optimal level of arousal” into his extraversion-introversion theory.

Answer 30

Since introverts have higher baseline levels of arousal than extraverts, they are above their optimal level of arousal more often than extraverts.

So, the generally over-aroused condition of introverts leads them to be more restrained and inhibited.

Question 31

Studies looking at nervous system responsiveness found that in response to moderate levels of stimulation introverts showed larger or faster responses than extroverts. However there was no difference in nervous system activity when people were presented with no stimulation or mild stimulation. Explain.

Answer 31

Suggests that introverts and extraverts are not different at resting levels but ARE different under moderate levels of stimulation. This suggests that the real difference between introverts and extraverts lies in their arousal RESPONSE not in their baseline arousal level.

Question 32

Jeffrey Gray has proposed the reinforcement sensitivity theory which is based on what 2 hypothesized biological systems in the brain?

Answer 32

The behavioural activation system (BAS) and the behavioural inhibition system (BIS)

Question 33

Describe a person with a reactive BIS

Answer 33

Sensitive to cues of punishment, frustration or novelty.

Vulnerable to unpleasant emotions like anxiety, fear, and sadness

Question 34

Describe a person with a reactive BAS

Answer 34

Especially sensitive to reward.

Vulnerable to positive emotions and tends to approach stimuli.

Inability to inhibit a behaviour when approaching a goal (impulsive)

Question 35

According to Gray’s theory, those who are impulsive (that is, those with a reactive BAS) seem to learn better from _________ compared to _________

Answer 35

reward; punishment

Question 36

Gray’s theory does well in describing the biological basis of what traits?

Answer 36

Impulsivity/extraversion and anxiety/neuroticism

Question 37

How does Hebb’s theory of optimal level of arousal explain sensation seeking?

Answer 37

If someone is under-aroused relative to their optimal level of arousal an increase in arousal is rewarding and thus they will seek it out

Question 38

How does Zuckerman’s research on neurotransmitters explain sensation-seeking?

Answer 38

Low MAO = too much nervous transmission taking place

Sensation seekers have low levels of MAO and thus high levels of neurotransmitters in the nervous system

Thus, sensation seekers have less inhibition in their nervous systems and thus less control over behaviour, thoughts, and emotions

Question 39

What does the tridimensional personality model suggest?

Answer 39

It suggests that 3 personality traits are tied to levels of 3 neurotransmitters.

Question 40

According to the tridimensional personality model, what personality trait is related to low levels of dopamine?

Answer 40

Novelty seeking

Question 41

According to the tridimensional personality model, what personality trait is associated with abnormalities in serotonin metabolism.

Answer 41

Harm avoidance

Question 42

According to the tridimensional personality model what personality trait is related to low levels of norepinephrine?

Answer 42

Reward dependence

Question 43

Not all alcoholics become addicted for the same reason. What does Cloninger argue?

Answer 43

Some alcoholics may begin drinking due to high novelty seeking - they drink to make up for low levels of dopamine

Some alcoholics may begin drinking because they are high in harm avoidance - they drink to relieve chronic stress and anxiety

Question 44

Assessment of differences in circadian rhythms in temporal-isolation studies have demonstrated…

Answer 44

that differences between morning and evening types of individuals appear to be due to differences in underlying biological rhythms

Question 45

It appears that differences in morningness-eveningness are especially related to what type of problems?

Answer 45

interpersonal compatibility

Question 46

Does a person with a shorter biological rhythm (morning person) or a person with a longer biological rhythm (evening person) reach peak body temperature earlier in the day?

Answer 46

A person with a shorter biological rhythm would hit their peak body temperature earlier in the day

Question 47

The morningness-eveningness questionnaire (MEQ) correlates with the time of day that peak body temperature was reached. What does this indicate?

Answer 47

Convergent validity

Question 48

Scores on the MEQ have been found to be stable over time.

TRUE or FALSE

Answer 48

True

Question 49

In some people the left frontal regions of the brain are more active while in others the right frontal areas are more active (aka brain asymmetry). What does a recent review on this topic indicate?

Answer 49

There is little to no evidence supporting the validity of resting frontal asymmetry as a personality indicator