Overview of Key Studies in IB Psychology: Aim, Method, Sampling, FIndings, Conclusion & IV/DV

Rosenzweig & Bennet (1972) - Aim

To investigate the effects of enriched or deprived environments on brain development in rats.

Rosenzweig & Bennet (1972) - Findings & Conclusion

Rats in enriched environments developed thicker cerebral cortexes and more neural activity. Environmental stimulation can lead to structural changes in the brain, supporting neuroplasticity.

Rosenzweig & Bennet (1972) - Method & Sample

Lab experiment (Independent measures); Lab rats randomly assigned to enriched or deprived environments.

Rosenzweig & Bennet (1972) - Strengths & Weaknesses

Strengths: Controlled variables, clear causal inference, support for neuroplasticity. Weaknesses: Low generalizability to humans, ethical concerns over animal use.

Maguire et al. (2000) - Aim

To investigate whether the brains of London taxi drivers would show structural changes due to extensive navigation experience.

Maguire et al. (2000) - Findings & Conclusion

Taxi drivers had a larger posterior hippocampus. Size correlated with years of experience. The brain can undergo structural changes (neuroplasticity) due to experience.

Maguire et al. (2000) - Method & Sample

Quasi-experiment; Self-selected sample of 16 right-handed male London taxi drivers with over 1.5 years of experience, compared to 50 matched right-handed male non-taxi drivers.

Maguire et al. (2000) - Strengths & Weaknesses

Strengths: Strong correlational evidence, real-world relevance, MRI technology. Weaknesses: Correlational, can't determine causation, limited generalizability.

Bouchard et al. (1990) - Aim

To investigate the influence of genetics and environment on intelligence (IQ).

Bouchard et al. (1990) - Findings & Conclusion

IQ concordance rate was 69% for MZA and 88% for MZT. Genetic factors play a major role in intelligence, though environment also contributes.

Bouchard et al. (1990) - Method & Sample

Correlational twin study; Self-selected sample of MZ twins reared apart (MZA) and together (MZT).

Bouchard et al. (1990) - Strengths & Weaknesses

Strengths: Rare sample, large-scale, strong genetic insights. Weaknesses: Self-selection, no full control over environments, correlational.

Atkinson & Shiffrin (1968) - Aim

To explain how memory is processed and stored using the multi-store model.

Atkinson & Shiffrin (1968) - Findings & Conclusion

Memory is structured in separate stores (sensory, short-term, long-term) with different durations and capacities. Memory follows a linear process through separate stores, influenced by attention and rehearsal.

Atkinson & Shiffrin (1968) - Method & Sample

Theoretical cognitive model; Based on lab studies and case studies such as HM.

Atkinson & Shiffrin (1968) - Strengths & Weaknesses

Strengths: Simple structure, empirical support from lab research. Weaknesses: Overly simplistic, doesn't explain deep processing or flashbulb memories.

Tversky & Kahneman (1974) - Aim

To investigate how heuristics affect decision-making under uncertainty.

Tversky & Kahneman (1974) - Findings & Conclusion

People relied on anchors even when the number was random, affecting estimates significantly. Humans rely on cognitive shortcuts (heuristics) that lead to systematic biases in thinking.

Tversky & Kahneman (1974) - Method & Sample

Lab experiment (Independent measures); Volunteer participants (students).

Tversky & Kahneman (1974) - Strengths & Weaknesses

Strengths: Replicable, clear demonstration of cognitive bias. Weaknesses: Low ecological validity, artificial scenarios, cultural limitations.

Glanzer & Cunitz (1966) - Aim

To investigate the serial position effect in memory recall.

Glanzer & Cunitz (1966) - Findings & Conclusion

Primacy and recency effects supported the idea of separate STM and LTM stores. Supports the multi-store model; STM and LTM function differently.

Glanzer & Cunitz (1966) - Method & Sample

Lab experiment (Repeated measures); Volunteer students.

Glanzer & Cunitz (1966) - Strengths & Weaknesses

Strengths: Clear empirical support for memory model. Weaknesses: Artificial task (word lists), limited real-world application.

Neisser & Harsch (1992) - Aim

To examine the reliability of flashbulb memories over time.

Neisser & Harsch (1992) - Findings & Conclusion

Large discrepancies appeared between initial and follow-up memories despite high confidence. Flashbulb memories are vivid but not necessarily accurate.

Neisser & Harsch (1992) - Method & Sample

Naturalistic longitudinal study; Convenience sample of college students.

Neisser & Harsch (1992) - Strengths & Weaknesses

Strengths: Real-life event, long-term memory tested. Weaknesses: Low control, small sample, retrospective bias.

Hofstede (1980) - Aim

To identify and compare cultural dimensions like individualism vs. collectivism.

Hofstede (1980) - Findings & Conclusion

Countries varied significantly on dimensions; U.S. scored high on individualism, China low. Culture shapes values and behavior; measurable through dimensions.

Hofstede (1980) - Method & Sample

Cross-cultural survey study; IBM employees across 70+ countries.

Hofstede (1980) - Strengths & Weaknesses

Strengths: Large cross-cultural data set, foundational theory. Weaknesses: Outdated, based on one company, limited representativeness.

Asch (1951) - Aim

To investigate how social pressure influences conformity.

Asch (1951) - Findings & Conclusion

75% conformed at least once; 32% overall conformity rate. People conform to avoid standing out, even when the group is clearly wrong.

Asch (1951) - Method & Sample

Lab experiment (Independent measures); Male college students (convenience sample).

Asch (1951) - Strengths & Weaknesses

Strengths: Controlled environment, clear results. Weaknesses: Low ecological validity, ethical issues (deception), cultural bias.

Kosfeld et al. (2005) - Aim

To investigate the effect of oxytocin on interpersonal trust.

Kosfeld et al. (2005) - Findings & Conclusion

Participants who received oxytocin showed significantly more trust in the economic game. Oxytocin increases trust, even in one-time interactions.

Kosfeld et al. (2005) - Method & Sample

Lab experiment (Double-blind); Volunteer males, randomly assigned to oxytocin or placebo group.

Kosfeld et al. (2005) - Strengths & Weaknesses

Strengths: Biological manipulation, supports neurochemical basis of behavior. Weaknesses: Artificial setting, nasal spray may not reflect natural oxytocin function.

Bandura, Ross & Ross (1961) - Aim

To investigate if children learn aggression through observation.

Bandura, Ross & Ross (1961) - Findings & Conclusion

Children who observed aggressive models were more likely to imitate aggressive behavior. Supports social learning theory: behavior is learned through observation.

Bandura, Ross & Ross (1961) - Method & Sample

Lab experiment (Matched-pairs); Preschool children from Stanford University nursery.

Bandura, Ross & Ross (1961) - Strengths & Weaknesses

Strengths: Controlled, replicable, supports theory. Weaknesses: Ethical issues, artificial setting, short-term effects only.

Broca (1861) - Aim

To investigate the brain area responsible for speech production.

Broca (1861) - Findings & Conclusion

Lesion in the left frontal lobe correlated with speech impairment. Speech production is localized in what is now called Broca's area.

Broca (1861) - Method & Sample

Case study (Post-mortem); Single patient 'Tan'.

Broca (1861) - Strengths & Weaknesses

Strengths: Groundbreaking discovery for localization of function. Weaknesses: Single case, post-mortem analysis, not generalizable.

Loftus & Palmer (1974) - Aim

To investigate the effect of leading questions on memory recall.

Loftus & Palmer (1974) - Findings & Conclusion

Estimates of speed and recall of broken glass were influenced by the verb used. Memory is reconstructive and can be distorted by post-event information.

Loftus & Palmer (1974) - Method & Sample

Lab experiment (Independent measures); Volunteer students.

Loftus & Palmer (1974) - Strengths & Weaknesses

Strengths: Controlled, demonstrated memory distortion. Weaknesses: Low ecological validity, artificial video clips.

Wedekind et al. (1995) - Aim

To investigate whether women are attracted to men with different immune system genes (MHC).

Wedekind et al. (1995) - Findings & Conclusion

Women preferred the scent of men with dissimilar MHC genes. Pheromones may influence mate selection based on genetic compatibility.

Wedekind et al. (1995) - Method & Sample

Lab experiment (Independent measures); Volunteer university students.

Wedekind et al. (1995) - Strengths & Weaknesses

Strengths: Biological basis for attraction, controlled conditions. Weaknesses: Artificial, limited ecological validity, birth control affected results.

Kahneman & Tversky (1979) - Aim

To investigate how people make decisions involving risk and losses.

Kahneman & Tversky (1979) - Findings & Conclusion

People are more sensitive to losses than to equivalent gains (loss aversion). People are not always rational; decisions depend on how choices are framed.

Kahneman & Tversky (1979) - Method & Sample

Lab experiment (Within-subjects); Volunteer participants.

Kahneman & Tversky (1979) - Strengths & Weaknesses

Strengths: Introduced Prospect Theory, widely applicable. Weaknesses: Hypothetical scenarios, limited real-world relevance.

Fisher, Aron & Brown (2005) - Aim

To investigate the role of dopamine in romantic love.

Fisher, Aron & Brown (2005) - Findings & Conclusion

Viewing photos of loved ones activated dopamine-rich brain areas. Romantic love activates reward-related brain circuits, similar to addiction.

Fisher, Aron & Brown (2005) - Method & Sample

Correlational fMRI study; Self-selected participants intensely in love.

Fisher, Aron & Brown (2005) - Strengths & Weaknesses

Strengths: Biological evidence using brain imaging. Weaknesses: Small sample size, correlational, can't determine causation.

Rosenzweig & Bennet (1972) - Independent Variable (IV)

Type of environment (enriched vs. deprived)

Rosenzweig & Bennet (1972) - Dependent Variable (DV)

Thickness of cerebral cortex and neural activity in rats

Maguire et al. (2000) - Independent Variable (IV)

Navigational experience (taxi driver vs. non-driver)

Maguire et al. (2000) - Dependent Variable (DV)

Size of posterior hippocampus (measured by MRI)

Bouchard et al. (1990) - Independent Variable (IV)

Genetic similarity (MZ twins reared apart vs. together)

Bouchard et al. (1990) - Dependent Variable (DV)

IQ score concordance rate

Atkinson & Shiffrin (1968) - Independent Variable (IV)

Not applicable - theoretical model

Atkinson & Shiffrin (1968) - Dependent Variable (DV)

Not applicable - theoretical model

Tversky & Kahneman (1974) - Independent Variable (IV)

Anchor number provided (e.g., 10 vs. 65)

Tversky & Kahneman (1974) - Dependent Variable (DV)

Estimated percentage of African countries in the UN

Glanzer & Cunitz (1966) - Independent Variable (IV)

Position of word in list (early, middle, late) and recall delay

Glanzer & Cunitz (1966) - Dependent Variable (DV)

Number of words correctly recalled from each position

Neisser & Harsch (1992) - Independent Variable (IV)

Time of memory retrieval (immediate vs. 2.5 years later)

Neisser & Harsch (1992) - Dependent Variable (DV)

Accuracy and confidence in flashbulb memory recall

Hofstede (1980) - Independent Variable (IV)

Country/culture of IBM employees

Hofstede (1980) - Dependent Variable (DV)

Scores on cultural dimensions (e.g., individualism)

Asch (1951) - Independent Variable (IV)

Presence of group pressure (confederates giving wrong answers)

Asch (1951) - Dependent Variable (DV)

Participant's conformity to incorrect answers

Kosfeld et al. (2005) - Independent Variable (IV)

Oxytocin vs. placebo nasal spray

Kosfeld et al. (2005) - Dependent Variable (DV)

Amount of money transferred in trust game

Bandura, Ross & Ross (1961) - Independent Variable (IV)

Type of model observed (aggressive, non-aggressive, none)

Bandura, Ross & Ross (1961) - Dependent Variable (DV)

Amount of aggressive behavior displayed by children

Broca (1861) - Independent Variable (IV)

Brain damage in Broca's area (observational)

Broca (1861) - Dependent Variable (DV)

Impairment in speech production

Loftus & Palmer (1974) - Independent Variable (IV)

Verb used in leading question (e.g., smashed vs. hit)

Loftus & Palmer (1974) - Dependent Variable (DV)

Estimated speed of the car and false memory of broken glass

Wedekind et al. (1995) - Independent Variable (IV)

Type of MHC gene match (similar vs. dissimilar)

Wedekind et al. (1995) - Dependent Variable (DV)

Pleasantness ratings of T-shirt odors

Kahneman & Tversky (1979) - Independent Variable (IV)

Framing of choices (gain vs. loss)

Kahneman & Tversky (1979) - Dependent Variable (DV)

Participants' choices (risk-averse vs. risk-seeking)

Fisher, Aron & Brown (2005) - Independent Variable (IV)

Photo shown (romantic partner vs. neutral acquaintance)

Fisher, Aron & Brown (2005) - Dependent Variable (DV)

Activation in dopamine-related brain regions (fMRI)

Tajfel et al. (1970) - Aim

To investigate whether categorization into groups (even if meaningless) is enough to cause in-group favoritism and out-group discrimination.

Tajfel et al. (1970) - Method & Sampling

• 64 schoolboys aged 14–15 from a UK school

• All from the same social and cultural background

• Randomly assigned to Klee or Kandinsky groups

• Lab experiment using the minimal group paradigm

• They did not know each other personally, and there was no real interaction between groups.

• Participants were asked to allocate points (which translated to money) to anonymous members of their own group or the other group using decision matrices.