Lesson 3.2.2

3.2.2 Brain scanning, twin and adoption studies Quiz: Pearson Edexcel Psychology, Unit 3

20 questions

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Lesson 3.2.2, Brain scanning, twin and adoption studies: 20 multiple choice questions for the Pearson Edexcel Psychology (9PS0), Unit 3: Biological psychology, written with Revision Ninja.

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The 20 questions

  1. Which brain-scanning technique produces structural images of the brain by taking X-ray measurements from many angles?

    • fMRI (functional magnetic resonance imaging), which detects changes in blood oxygenation linked to neural activity in the brain
    • EEG (electroencephalography), which records electrical activity from electrodes placed on the scalp of the participant
    • CAT (computerised axial tomography), which builds detailed structural images from X-ray slices taken around the head
    • PET (positron emission tomography), which tracks a radioactive glucose tracer to show the brain's activity levels over time

  2. What does PET scanning measure in the brain?

    • The structure of the skull and the thickness of the bone, which is used to identify areas of injury after an accident
    • The activity of the brain, by tracking a radioactive tracer that accumulates where there is higher metabolic activity
    • The magnetic field produced by the heart, which shows the timing of each heartbeat across the participant's chest
    • The electrical spikes of individual neurons, recorded directly from the surface of the brain in a surgical procedure

  3. fMRI scanning is often preferred to PET for studying brain function because:

    • it uses no radioactive tracer and gives better spatial detail of changes in brain activity
    • it measures individual neurons directly, which PET cannot do because the tracer is too large to reach the cell bodies
    • it uses ionising radiation, which penetrates the brain more deeply and produces more detailed images of brain tissue
    • it is cheaper and quicker than any other method, and it requires no equipment or trained operators to run the scan

  4. In a twin study, what does a concordance rate of 100% for a behaviour in monozygotic twins suggest?

    • That the behaviour is entirely caused by the environment, since twins share identical experiences in their home settings
    • That the behaviour is caused by chance alone, because twins are always identical in every aspect of their development
    • That the behaviour is unrelated to genes, because identical twins can never share the same trait in any circumstances
    • That the behaviour has a strong genetic component, since monozygotic twins share all of their genes in common

  5. Why are dizygotic twins compared with monozygotic twins in twin studies?

    • To estimate genetic contribution, since dizygotic twins share about half their genes, as siblings do
    • To confirm that the trait is learned, since dizygotic twins are always raised apart and so cannot share any environment
    • To find out whether the trait is shared more by twins who share the same environment, which removes any effect of genes
    • To check whether the researcher has made an error in coding, because dizygotic twins always have identical scores on tests

  6. In an adoption study, researchers compare adopted children with their biological and adoptive families. What is the key purpose of this design?

    • To ensure the children receive identical treatment in both families, which removes any influence of genes from the study entirely
    • To separate the effects of genes, shared through biological parents, from the effects of the environment, shared through adoptive parents
    • To prove that the adoptive environment is always the most important influence on a child's personality development over time
    • To show that adoption always causes children to become more aggressive, since they are removed from their natural parents at birth

  7. A study finds that adopted children resemble their biological parents in aggression more than their adoptive parents. What does this suggest?

    • That genetic factors may contribute to aggression, since resemblance to biological relatives is stronger than to adoptive ones
    • That aggression is caused entirely by hormones, since the adopted children's hormone levels resemble those of their biological parents
    • That the environment provided by adoptive parents is the main cause of aggression in every adopted child in the study
    • That aggression cannot be measured in adopted children, because adoption disrupts any consistent behaviour across development

  8. Which limitation applies to twin studies that assume equal environments for MZ and DZ twins?

    • The assumption may be false, since MZ twins are often treated more similarly by others, which can inflate estimates of genetic influence
    • The assumption is always true, so twin studies cannot produce any evidence that might contradict a genetic explanation at all
    • The assumption makes twin studies irrelevant, since the environment has no effect on any behaviour in childhood or adulthood
    • The assumption affects only adoption studies, so twin studies are not limited by it in any form at any point in the research

  9. A researcher uses fMRI to compare brain activity during an aggressive task with a neutral task. Which measure does fMRI use to show this change?

    • The change in blood oxygenation, which reflects increased neural activity in regions working harder
    • The electrical potential recorded at a single electrode, which shows only the activity of the outer layer of the cortex
    • The concentration of a radioactive tracer that accumulates at the sites of neural activity in the brain during the task
    • The number of X-ray beams that pass through each slice of the brain, which reveals changes in the density of tissue

  10. Which ethical issue is most relevant to using PET scans in research on aggression?

    • The use of a magnetic field, which may affect the cardiac pacemakers of some participants, so it must always be avoided entirely
    • The use of a questionnaire, which may produce social desirability bias and so must be piloted before any scan takes place
    • The use of a sample of university students, which is always illegal in psychology research on any topic of study at all
    • The use of a radioactive tracer, which exposes participants to a small amount of radiation that must be justified by the research

  11. Which is a strength of brain-scanning techniques in biological psychology?

    • They do not require any participants, since the brain can be scanned without any involvement from the person being studied
    • They offer objective measures of brain structure or activity, which can be compared across participants and studies
    • They avoid all practical issues, because the images are always perfectly clear and the scanner never produces artefacts or noise
    • They show causation directly, since a scan proves that the activated area is the single cause of the observed behaviour

  12. Which limitation of brain scanning is most relevant when using it to explain aggression?

    • Scans always produce results that exactly match the behaviour of individual participants, which means that they are too precise
    • Scans show correlation rather than causation, so an active region during aggression does not prove it causes the aggression
    • Scans can only measure the blood pressure of the participant, which is unrelated to the function of any part of the brain
    • Scans cannot show which brain regions are active, so they are unable to provide any information about brain function at all

  13. A twin study reports a concordance rate of 50% for aggression in MZ twins and 20% in DZ twins. Which conclusion is best supported?

    • Genes may contribute to aggression, since MZ twins are more similar than DZ twins, but the environment also plays a role
    • Aggression is entirely genetic, because MZ twins share some of the trait in the study, which proves full heritability
    • Aggression is entirely environmental, since DZ twins show lower concordance and therefore cannot share any genetic influence
    • The study shows no genetic or environmental influence, because concordance rates are always equal in twin studies of any trait

  14. Gottesman and Shields (1966) used twin data to study schizophrenia. Which feature of twin research does their work illustrate?

    • That twin studies can only be conducted with adult participants who have been raised apart since birth in different homes
    • That twin studies can only be used for aggression, and cannot be applied to any mental health disorder or clinical condition
    • That twin studies always show that the disorder has no genetic basis, because twins never share the same illness
    • That twin studies can estimate genetic contribution to a disorder by comparing concordance in MZ and DZ twins

  15. Why might an adoption study be a stronger design than a twin study for separating genes from environment?

    • Because adoption studies are always randomised, so the selection of children into families is controlled by the researcher
    • Because adoption studies do not require any measurement of behaviour, so they avoid the problem of measuring traits accurately
    • Because adopted children always share their genes with their adoptive parents, so the two sources of influence are confused
    • Because adoption studies separate biological relatives from the rearing environment, which avoids equal environment assumptions

  16. A critic argues that adoption studies are limited because adoption agencies place children selectively. What does this criticism mean?

    • Adoptive families may differ systematically from the general population, so the sample may not represent typical families
    • Adoption agencies only place children who are already aggressive, so the adopted sample always shows aggression at the start
    • Children are placed in families at random, so the study has no problems with its sampling and generalises to all children
    • Adoption agencies always place children with biological relatives, so no adoptive environment is ever truly independent of genes

  17. Which statement best describes the difference between PET and fMRI scans?

    • PET measures electrical signals at the scalp, while fMRI measures radioactive tracers injected into the bloodstream of participants
    • PET and fMRI both use X-rays to produce images of the brain, differing only in the speed at which each scan can be completed
    • PET measures structure and fMRI measures activity, which is the reverse of how each scanner is typically used in research
    • PET uses a radioactive tracer to show activity; fMRI detects blood oxygen changes with magnetic fields

  18. A researcher wants to examine whether brain activity in the prefrontal cortex differs between aggressive and non-aggressive participants. Which technique is most suitable for showing activity during a task?

    • fMRI, because it shows blood-oxygen changes linked to activity during the task, with good spatial detail of the cortex
    • A skull X-ray, because it shows the thickness of the prefrontal bone, which reflects the amount of activity in the region
    • A blood test for testosterone, because the hormone level directly shows which regions of the cortex are most active
    • CAT, because it produces a structural image of the prefrontal cortex that shows which regions are working during the task

  19. Which combination of features best describes a monozygotic twin study?

    • Twins share essentially all their genes and are always of the same sex, which allows genetic influence to be estimated
    • Twins share about half their genes and are always of different sexes, which is used to separate sex from genetic influence
    • Twins share all their genes only if they are raised in the same home, so the environment changes their genetic makeup
    • Twins share no genes at all, because they are raised in the same home, so the environment is the only influence on them

  20. An adoption study finds that children adopted in infancy show similar levels of aggression to their biological mothers, even though they were not raised by them. What does this best demonstrate?

    • That the adoptive environment has no effect at all on any child's behaviour, since genes always fully determine aggression
    • That aggression is purely learned from the adoptive family, since the biological mother had no direct contact with the child
    • That children always copy their biological mothers, because they observe them during the first days of life in hospital
    • That genetic factors likely contribute to aggression, since resemblance to a biological relative persists despite different upbringing

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