IB Psychology - Core Approaches

22 studies from the IB Psychology textbook.

Maguire (2000) Aim

To see whether the brains of London taxi drivers would be different given their remarkable knowledge of the city and many hours spent at the wheel.

Rogers & Kesner (2003)

A key study investigating the role of acetylcholine in the formation of spatial memory.

Wedekind (1995)

A key study investigating whether one’s MHC would affect mate choice based on body odor.

Kendler et al. (2006)

A key study investigating the heritability of major depression, gender differences, and the influence of genetic and environmental factors.

Maguire (2000) Participants

16 right-handed male Taxi drivers who completed the “Knowledge” test + had their license for at least 1.5 years.

Maguire (2000) Method

Quasi-experiment, MRI scans—the brains of the 16 Taxi-drivers were scanned, then compared to the controlled samples: the brains of 50 right-handed males who did not drive taxis taken from a MRI database.

Maguire (2000) IV

Occupation group—naturally-occuring variable, not manipulated by researchers.

Maguire (2000) DV

Structure and volume of hippocampus.

Maguire (2000) Findings

• Posterior Hippocampus Enlargement in Taxi Drivers

• Smaller Anterior Hippocampi in Taxi Drivers

• Correlation Between Experience and Brain Structure

• No Other Brain Regions Affected

Maguire (2000) Implications

• The study suggests that the brain can change structurally in response to environmental demands and experience — in this case, long-term navigation experience.

• Supports the idea of neuroplasticity, especially in adults.

• Highlights that different regions of the hippocampus may have specialized roles:

◦ Posterior: storing and using learned spatial information.

◦ Anterior: involved in learning new environments.

Maguire (2000) Strengths

• Single-Blind Design: Brain scans were coded so analysis could be done blindly, removing the possibility of researcher bias.

• Quantitative Methods of Measurement MRI scans and pixel-counting provided quantitative data on the brain structure.

• Ethical Standards - Non-invasive method, informed consent, no harm done to participants.

• Controlled for Confounding Variables - Use of right-handed middle-aged males only.

Maguire (2000) Limits

• As the IV was not controlled, a causal relationship cannot be established, only a correlational one.

• The MRI only looked as structure, not function—we don’t directly see the hippocampus in action during spatial tasks.

Rogers & Kesner (2003) Aim

To investigate the role of acetylcholine in the formation of spatial memory.

Rogers & Kesner (2003) Participants

30 rats.

Rogers & Kesner (2003) Method

True experiment.

• Rats were acclimated to a Hebb-Williams maze to reduce fear.

• Independent-Samples Design with Random Allocation to Two Conditions

◦ Experimental group: Injected with scopolamine (blocks acetylcholine receptors).

◦ Control group: Injected with a saline solution (placebo).

• Injections were made directly into the hippocampus.

• Memory encoding was assessed by comparing errors in the first and last five trials of Day 1.

• Memory retrieval was assessed by comparing the first five trials of Day 2 to the last five trials of Day 1.

Rogers & Kesner (2003) IV

Scopaline (blocks acetylcholine receptor sites)

Rogers & Kesner (2003) DV

Time taken for rats to locate food at the corner of a Hebb-Williams maze.

Rogers & Kesner (2003) Findings

The scopolamine group took longer and made more mistakes, whereas the control group learned faster and made fewer mistakes.

Rogers & Kesner (2003) Implications

Acetylcholine is essential for memory formation. Research could one day lead to the development of treatments for Alzheimer’s and other memory-related diseases.

Rogers & Kesner (2003) Strengths

Rigorously controlled experiment with a placebo condition to avoid confounding variables.

Rogers & Kesner (2003) Limits

• Reductionist approach to memory.

• Results from animal testing might not always be applicable to human psychobiology.

Meaney et. al (1988) Aim

Determine the role of glucocorticoids (stress hormones) on memory.

Meaney et. al (1988) Participants

Newborn rats.

Meaney et. al (1988) Method

True experiment.

• Newborn rats were separated from their mothers at birth.

• Independent-Samples Design with Random Allocation to Two Conditions

◦ Treatment Group: handled daily for 15 minutes from birth to weaning, brushed to mimic maternal grooming.

◦ Control Group: not groomed or handled.

• At 2 years old, rats were placed in a milky water maze with a hidden platform.

• Researchers tracked memory performance based on the rats' ability to locate the platform using past learning.

Meaney et. al (1988) IV

Type of early-life experience—whether or not the rat recieved maternal attention.

Meaney et. al (1988) DV

Memory performance—hippocampi cell density

Meaney et. al (1988) Findings

• Rats that were not handled exhibited higher cortisol levels, worse spatial memory, and hippocampal cell loss

• Handled rats showed lower cortisol levels, better memory, healthier hippocampal structures.

Meaney et. al (1988) Implications

• Early life experiences shape brain development.

• Stress harms the hippocampus (long-term exposure to cortisol can lead to hippocampal neuron death).

• The findings may help explain how chronic stress in childhood could contribute to cognitive decline or disorders like Alzheimer’s disease later in life.

Meaney et. al (1988) Limits

• Lacks ecological validity

• To measure hippocampal volume in rats, the animals needed to be killed.

Wedekind (1995) Aim

To determine whether one’s MHC would affect mate choice based on body odor.

Wedekind (1995) Participants

49 female + 44 male students from the University of Bern.

Wedekind (1995) Method

Quasi-experiment, double-blind design where men wore T-shirts and women rated them on intensity, pleasantness, and sexiness.

Wedekind (1995) IV

Whether the T-shirt came from a man with an MHC similar or MHC dissimilar to the woman.

Wedekind (1995)DV

The women’s ratings of the shirt (1-10) based on: Pleasantness, Sexiness, Intensity

Wedekind (1995) Findings

Women rated T-shirts from MHC-dissimilar men as more pleasant on oral contraceptives. Women preferred MHC-similar odors.

Wedekind (1995) Implications

Humans may be biologically driven to prefer mates with different MHC genes, promoting genetic diversity and stronger immune systems of offsprings. Oral contraceptives can alter natural preferences.

Wedekind (1995) Strengths

• Succesfully replicated.

• Double-blind: neither researchers nor participants knew which t-shirt they were being exposed to.

Wedekind (1995) Limits

Reductionist approach to human attraction.

Kendler et. al (2006) Aim

To investigate the heritability of major depression.

Kendler et. al (2006) Participants

15,493 complete twin pairs from the Swedish Twin Registry.

Kendler et. al (2006) Method

Telephone interviews conducted, trained interviewers assessed lifetime major depression using a modified DSM-IV criteria.

Kendler et. al (2006) IV

Genetic relatedness; Sex

Kendler et. al (2006) DV

Lifetime diagnosis of major depression

Kendler et. al (2006) Findings

Higher concordance for major depression in monozygotic (identical) twins compared to dizygotic (fraternal) twins. Women showed higher heritability rates than men.No correlation between time living together and rates of depression.

Kendler et. al (2006) Implications

Major depression is moderately heritable.Genetic risk factors for depression appear to be stronger in women. Findings support the reliability of European twin studies on depression.

Kendler et. al (2006) Limits

Correlational: no causal relationship can be confidently determined. Information about life experiences and depressive symptoms were self-reported (relevant to gender gap). Diagnoses may not be the most reliable as they’re done over telephone.

Hilliard & Liben (2010) Aim

Investigate role of social identity theory in the formation of gendered stereotypes.

Hilliard & Liben (2010) Participants

57 US children ranging from 3 years 1 month to 5 years 6 months.

Hilliard & Liben (2010) Method

Field-experiment.

Hilliard & Liben (2010) IV

Exposure to gender salience/gendered language from teachers

Hilliard & Liben (2010) DV

"Gender flexibility" and acceptance of stereotypes.

Hilliard & Liben (2010) Findings

After two weeks, children in the high salience condition showed significantly increased gender stereotypes and decreased play with other-sex peers.

Hilliard & Liben (2010) Implications

Social labeling influences identity: gender schemas are socially constructed and reinforced by environmental factors. Categorization leads to stereotypes Ingroup vs Outgroup Formation

Hilliard & Liben (2010) Strengths

High ecological validity (applicable to real-life situations)

Hilliard & Liben (2010) Limits

Sampling bias - Ethical conerns around children’s psychological development.

Schaller et. al (1991) Aim

How social category salience can lead to development of stereotypes of “out-group”.

Schaller et. al (1991) Participants

141 introductory psychology students

Schaller et. al (1991) Method

True experiment. Participants told they were either in Group A or Group B or control group; told that there were more people in Group A than in Group B.

Schaller et. al (1991) IV

Categorization of Group A, Group B or control group.

Schaller et. al (1991) DV

Participant rankings of each group

Schaller et. al (1991) Findings

Each group tended to rate their in-group as more positive. Control group did not have significant difference in rating of Groups A and B.

Schaller et. al (1991) Implications

Group categorization alone is enough to create bias and stereotype formation, even with no history or conflict between groups.

Schaller et. al (1991) Strengths

True experimental design. Balanced materials (positive/negative traits)

Schaller et. al (1991) Limits

Artifical setting, low ecological validity

Joy, Kimball & Zabrack (1986); Charlton et al (2002) Aim

Investigate how television may play a role in the development of aggressive behaviors in children.

Joy, Kimball & Zabrack (1986); Charlton et al (2002) Participants

• Joy: 120 Notel children (Canadian)

• Charlton: 160 St. Helena children (remote Atlantic island)

Joy, Kimball & Zabrack (1986); Charlton et al (2002) Method

Longitudinal natural experiments.

Joy, Kimball & Zabrack (1986); Charlton et al (2002) IV

Exposure to television.

Joy, Kimball & Zabrack (1986); Charlton et al (2002) DV

Levels of aggressive behaviour in children.

Joy, Kimball & Zabrack (1986); Charlton et al (2002) Findings

• Joy, Kimball, & Zabrack: The aggressive behavior of children in Notel increased significantly from 1973 to 1975

• Charlton: No increase in aggressive or antisocial behaviour in St. Helena’s children.

British TV station may have not presented examples children from St. Helena could identify with, because most of the people onscreen were white and upper-middle class.

Joy, Kimball & Zabrack (1986); Charlton et al (2002) Implications

• Media can influence behavior: Joy's findings suggest that exposure to aggressive television content may increase aggressive behavior in children.

• Context moderates media effects: Charlton's study showed no increase in aggression, highlighting the role of cultural context, adult supervision, and self-efficacy in moderating media influence.

Joy, Kimball & Zabrack (1986); Charlton et al (2002) Strengths

High ecological validity. Researchers worked in teams and conferred with parents to triangulate data, increasing reliability of findings.

Joy, Kimball & Zabrack (1986); Charlton et al (2002) Limits

Low internal validity because of the prescence of uncontrollable factors. Difficult to replicate

Steele & Aronson Aim

Investigate how a stereotype threat may affect Black students’ academic performance on tests.

Steele & Aronson Participants

114 male and female, mixed black and white undergraduates from Stanford University

Steele & Aronson Method

Participants were given a standardized test of verbal ability and randomly allocated to two conditions a. participants were told it was a test to diagnose “intellectual ability” b. participants were told it was a test of “problem-solving skills”

Steele & Aronson IV

Race of the students; Test descriptions

Steele & Aronson DV

How Black Americans did on standardized test in contrast to white Americans

Steele & Aronson Findings

Black participants did poorly when believed that test was a test of ability, but did just as well as white participants when believed that it was test of problem-solving skills

Steele & Aronson Limitations

Stereotype threat has impact on academic performance on tests.

Steele & Aronson Strengths

Participant variability was minimized. measures were taken to ensure that all participants were within norm of verbal performance

Steele & Aronson Limits

Difficult to generalize: made up of Stanford students; Confounding variables: doesn’t necessarily mean that participants experienced stereotype threat

Martin & Halverson Aim

Investigate how schemas play a role in how children understand and learn about gender roles.

Martin & Halverson Participants

48 children (half male, half female) aged 5-6 years old.

Martin & Halverson Method

True experiment, Children were shown 16 images

Martin & Halverson IV

Photos shown to the children.

Martin & Halverson DV

Ability to recall gender-specific activities.

Martin & Halverson Findings

Both boys and girls were more likely to misremember the sex of the actor when the picture showed a gender-inconsistent activity. Children were more confident in their memory of the actor's sex when the activity was gender-consistent.

Martin & Halverson Implications

Supports gender schema theory, selective memory bias, early development of stereotypes

Martin & Halverson Strengths

Highly standardized, can be replicated, controlled for response bias

Martin & Halverson Limits

Low ecological validity, task was artificial and highly controlled

Berry (1967) Aim

Measuring the level of conformity in collectivistic & individualistic societies.

Berry (1967) Participants

120 participants from 3 different cultures: Temne Inuit & urban & rural Scots

Berry (1967) Method

Quasi-experiment (6 trials total)

Berry (1967) IV

Cultural background

Berry (1967) DV

Level of conformity.

Berry (1967) Findings

Temne - collectivist culture - had a higher rate of conformity when told what other Temne believed, though it was incorrect. Scots - individualistic culture - lower rate of conformity than Temne Inuits - individualistic culture - lower rate of conformity than Scots

Berry (1967) Implications

Collectivist cultures tend to conform to their own group’s ideas, while individualistic cultures do not.

Berry (1967) Strengths

Control condition strengthened internal validity, highly replicable

Berry (1967) Limits

Lacks ecological validity. Causality cannot be determined due to quasi nature of experiment design