IB Psychology Studies

(Bandura 1961)

• Hypothesis/Aim: children would imitate aggressive behaviors if they were exposed to adult models displaying the same aggressive behavior.

• Context: 

  • Learning takes place through active cognitive processes, not just observation.

  • In SCT, these essential learning processes are attention: actively focusing while models demonstrate behaviors; retention: remembering learned behaviors, reproduction: being able to replicate learned behaviors, and motivation: being driven to repeat learned behaviors. 

  • The study also demonstrated the “social” aspect of SCT, which states that socialization forces (SFs) are the main models/influences on these processes. This highlights how in addition to executing active cognitive processes, people also need to be actively engaged with SFs to learn and execute new behaviors.

• Procedure: 

  • 72 3-6 year olds. 1/2 were boys, 1/2 were girls. Split into 3 groups. 

  • Each child was in a playroom full of toys, along with the experimenter, an adult, and a bobo doll.

  • Depending on the group the child was in, the adult either:

    • verbally and physically assaulted the bobo doll aggressively,

    •  or played with it gently; in the third group, there was no adult model present (control).

  • After observing, the child was taken to be alone in another similar playroom:

    • with aggressive toys (ex. a mallet)

    • Non aggressive toys (ex. crayons)

    • The bobo doll 

• Findings: 

  • Children who observed the “aggressive” model were more likely to demonstrate the same aggressive behavior towards the doll, down to the same insults and actions. 

  • Children who observed the gentle model were more likely to demonstrate the same gentle approach towards the Bobo doll. 

• Conclusion:

  • Supported Bandura’s Hypothesis: children would imitate aggressive behavior after observing it. 

  • Learning these behaviors required not just observation, but the use of cognitive processes, essential parts of SCT. 

  • Adults= models. Children 1) actively observed them, which allowed the children to 2) remember the modeled behaviors, 3) have enough motivation to reproduce it and thus effectively learn modeled behavior. 

The study demonstrated how important cognitive processes are in learning modeled behaviors, as well as how crucial SFs are in modeling those behaviors,  which directly supports SCT. 

Bandura (1965)

• Hypothesis/Aim: investigate how positive and negative reinforcement impacted the acquisition of a new behavior. Bandura hypothesized that children who actively observed aggressive behavior were more likely to partake in it, but not necessarily understand the behavior. This aligns with SCT, which proposes that active attention will lead to retention of a new behavior, and the motivation that they can replicate that behavior. 

• Procedure: 

  • 66 participants (33 boys and 33 girls) , who on an average were 4 years old 

  • Each child was brought into a fake waiting room individually, where they watched a video before they could go into the main playroom. In this video, a child watched as adult shouted at the bobo doll to move, and when it didn’t, he/she physically attacked in four different ways (punching, hitting, kicking, and throwing balls at it) two times. Then, the adult stopped, and let the child play with the bobo doll.

    • participants had been randomly assigned to one of three groups, each of which was comprised of 11 boys and 11 girls. The children in the video emulated the adult’s violent behavior, but depending on the participant group, they were either rewarded, scholded, or received no consequences for their actions. 

  • Afterwards, the participants were escorted into a playroom with similar toys, including the bobo doll, and were given 10 minutes to play. The researchers filmed their actions

  • Finally, the experimenter entered the room and told the participants that they would receive either juice or stickers for every aggressive action they repeated from the video

• Findings: 

  • Children who observed the child model being rewarded for their actions were more willing to demonstrate the aggressive behavior, while children who observed the child model being chastised were less willing. 

  • However, when children were later offered rewards to copy the behavior, they all showed similar levels of willingness. 

• Conclusion:

  • Supported Bandura’s Hypothesis: children would imitate aggressive behavior after observing it. 

  • Learning these behaviors required not just observation, but the use of cognitive processes, essential parts of SCT. 

  • Adults= models. Children 1) actively observed them, which allowed the children to 2) remember the modeled behaviors, 3) have enough motivation to reproduce it and thus effectively learn modeled behavior. 

  • While punishment can make kids less likely to immediately copy bad behavior, it doesn't stop them from learning it. If there is a good enough reason, such as a reward they will still know how to do it later on.
    
    

McConnell et al (1994)

• Hypothesis/Aim: investigate the extent of illusory correlations depending on in-group size, out-group size, and negative behavior. 

• Context:

  • People are in many in-groups (social groups that they identity with) simultaneously, and have different identities that they display depending on what group they’re with. Outgroups are groups they don’t identify with, and to strengthen one’s self esteem and thus in-group identity, people do social comparisons: displaying negative biases towards their out-groups and positive biases towards their in-groups. 

  • McConnell et al demonstrated how these biases influence people to display illusory correlations to incorrectly correlate distinctive, usual and “wrong” behaviors to people in out-groups.

  • These factors, according to SIT, lead people to categorize others in order to heighten their perceived differences between themselves and those in out-groups, which strengthens their own identity. 

• Procedure: 

• Researchers presented 102 Indiana University students with positive & negative behaviors proportionally done by 2 fictional groups, labeled group A and group B. 

• After reading about both groups, participants did a series of memory tasks:

  • Categorizing which group did which behaviors through recall & through an unlabelled list

  • Estimating the number of undesirable behaviors each group 

  • Rating how likable they found each group

• Findings: 

• participants estimated that Group B did more undesirable behaviors than Group A

• More participants categorized undesirable behaviors with Group B than Group A.

• Though both groups did a proportional number of desirable to non-desirable behaviors (Group A with 16:8 & Group B with 8:4), no participants knew this

• Because Group B had a lower number of total behaviors, it’s negative behaviors stood out more than Group A’s, which had 2x as more total behaviors. 

• Conclusion:

  • Support hypothesis that negative & infrequent behaviors would cause strong illusory correlations than mundane and frequent behaviors. 

  • Throughout the study, participants subconsciously categorized themselves with Group A & its desirable behaviors, giving them an in-group bias towards them. 

  • In an effort to boost their self esteem and distance themselves from Group B’s undesirable behaviors, subjects developed an out-group bias against Group B & showed an illusory correlation towards them. 

  • Social categorization and in-group biases, which were prominently displayed throughout the study, were key parts of SIT, and have been seen through a wide variety of social settings outside of the context of the study.

Bar Tal (1996)

• Hypothesis/Aim:  see how the cultural upbringing of Jewish children ins Israel affected their stereotypes of Arabs. 

• Context

  • Stereotypes, simplified schema-based generalizations of identifiable groups, help the mind categorize others in order to better identify them as part of an in-group or out-group. 

  • These stereotypes help individuals understand themselves by using others as a frame of reference.

  • Although stereotypes are functional, they aren’t reliable (esp. In the presence of different racial groups)

    • Rely on prejudice towards other groups to form judgements

    • Assume all out-group members are similar & disregard their individuality

• Procedure

  • Bar-Tal individually showed 214 2-6yr olds (102 boys and 112 girls) 4 illustrations of Arab men, ranging from most to least stereotypically Arab.

  • Bar-Tal asked the subjects to identify which pictures showed Arab men. 

• Findings

  • 30% of 2.5-3.5 yr olds and 80% of 5.5-6.6 yr olds identified the illustrations of the 2 most stereotypically Arab-looking men as Arab. 

• Conclusion

  • Findings demonstrated stereotypes in action, as they showed how Israeli children had alr acquired stereotypes of different cultures at a young age.

  • Using these stereotypes, the children categorized themselves as from an in group & the Arabn men as an out group. This categorization could influence their views on Arab men in the future and could lead to prejudice. 

Hofstede (1983)

• Hypothesis/Aim: find method to mitigate/reduce conflicts caused by cultural differences at IBM.

• Context

  • Cultural dimensions are commonly held values of a group that affect its behavior and exist in a spectrum. 

  • The norms & overall culture of a group builds its values, so each cultural group varies in its degree of support and opposition to various cultural dimensions.

• Procedure

  • Hofstede gave questionnaires to 167,000 employees from 40 countries (translated into their native languages), which polled their opinions on different issues in the workplace. 

  • Hofstede categorized the results into 4 categories, which became the cultural dimensions of his framework. Employees gave a score of 0 - 100 (0 totally disagreeing and 100 totally supportive) for their opinions on:

    • Power Distance (how acceptant people were to unequal distributions of power) (PDI)

    • Uncertainty Avoidance (how tolerant people were to flexibility & ambiguity in the workplace) (UAI)

    • Masculinity vs Feminity (how much people valued ends over means) (MF)

    • Individualism vs Collectivism (IDV)

• Findings

  • Germanic countries (the US, Canada, & European countries) had the lowest PDIs & highest IDVs, which Asian countries displayed opposite patterns. 

  • Nordic countries had the lowest MFs 

  • Asian, Latin-American, and European countries influenced by German culture had higher MF scores.

• Conclusion

  • By identifying trends in cultural values between different cultures in different countries, Hofstede demonstrated the existence of cultural dimensions. 

  • His findings provided a framework for people to understand similarities & differences among different cultures, and reduce potential cross cultural conflicts. 

Schwartz (1992)

• Hypothesis/Aim:  to determine existence of a universal set of cultural dimensions 

• Context

  • Cultural dimensions are commonly held values of a group that affect its behavior and exist in a spectrum. 

  • The norms & overall culture of a group shapes which values are prioritized, so each cultural group varies in its degree of support and opposition to various cultural dimensions.

• Procedure

  • Schwartz administered a survey to over 25,000 participants in 44 different countries, who had different occupations and ages. 

  • Participants were shown 56 societal values (eg. security), each with an explanation. Local researchers could add additional culturally relevant values as needed. 

  • Participants noted which values were most and least important to them

  • They then rated all 56 (or more) on a 9 point scale, with 1 opposing their values and 9 being of supreme importance 

• Findings

  • Schwartz identified 10 universal value types shared across cultures:

    • Openness to change:

      • Self Direction

      • Stimulation

    • Self enhancement:

      • Hedonism

      • Achievement

      • Power Universalism

    • Stuff for others:

      • Benevolence

    • Conservation

      • Conformity

      • Tradition

      • Security

• Conclusion: Despite the absence of a single universal set of cultural dimensions, Schwartz demonstrated that these ten value types are acknowledged globally, with varying degrees of importance across cultures.

  • While all cultures recognized these values, they prioritized them differently

    • Western cultures: prioritizing self-direction, while collectivist cultures emphasize conformity and tradition

Ochs (1982)

Hypothesis/Aim:
To investigate language development and the process of language socialization in traditional Samoan households, especially among young children, and to understand how enculturation occurs through language use and family interaction.

Context:
Enculturation is the process of learning the rules, expectations, and norms of one’s culture. Each person experiences enculturation in unique ways depending on their upbringing, family dynamics, and community values. In many cultures, the way adults speak to and interact with children reflects deeper societal structures like social hierarchy and collectivism. Understanding these practices helps reveal how culture-specific values are reinforced.

Procedure:
Researchers observed 23 children under age six in traditional Samoan households over ten months, visiting every five weeks. During visits, they recorded the children’s conversations, and family members transcribed the recordings. Researchers analyzed how adults and older siblings interacted linguistically with the children.

Findings:
Samoan adults rarely spoke directly to young children, even when they were present. Instead, adults spoke about or on behalf of children to other adults. Older children, siblings, or peers were the ones who spoke to and taught younger children, not the adults. This reflected Samoan societal structure, where children hold a low position in the social hierarchy and are expected to learn through passive observation rather than direct instruction.

Conclusion:
The way Samoan children learned language also taught them cultural values like respect for authority and collectivism. Their enculturation happened through modeled behaviors, family structure, and social interaction patterns that emphasized learning from those slightly older or more experienced, rather than the most senior members of society. This study demonstrates how language is a key mechanism through which enculturation and cultural values are transmitted.

Miller (1956)

Hypothesis/Aim:
To explore the limits of human information processing, especially short-term memory, and understand how many items (or bits of information) the average person can hold in mind at once.

Context:
Human cognition is limited in the amount of information it can accurately process and retain at once. While information theory introduced formal ways of quantifying information (in bits), Miller explored how these limits play out in real-world memory tasks like listening to tones or remembering number sequences. He famously noted that many cognitive tasks seemed to hit a limit around 7 ± 2 items, also known as the “magical number seven.”

Procedure:
Miller analyzed multiple experiments, such as:

• Pollack’s study on tone identification, where participants identified tones (100–8000 cps), each linked to a number. Accuracy dropped after about 6 tones, indicating a processing limit around 2.5 bits.

• Hayes’ study on short-term memory, where participants (white male college students) heard lists of items—ranging from binary digits, letters, to full words—and tried to recall them in order. No matter the information complexity, subjects typically recalled 7 ± 2 chunks of information.

Findings:
Participants could:

• Accurately distinguish and identify 5–9 tones, intensities, positions, or quantities, depending on the task.

• Remember 7 ± 2 chunks of information (e.g., digits, letters, words), regardless of how much information each chunk contained (measured in bits).

• Increase memory performance by recoding or grouping items into larger chunks (e.g., recoding binary digits into decimal, or organizing random digits into familiar patterns).

Conclusion:
The capacity of short-term memory is best measured in chunks, not bits. While absolute judgment tasks (like tone identification) are limited by information capacity (~2.5 bits), immediate memory is limited by the number of meaningful units a person can recall (7 ± 2 chunks). Recoding and chunking strategies can stretch these limits, allowing us to remember more by organizing information more efficiently.

Bartlett (1932)

Hypothesis/Aim:
To investigate how cultural schemas affect memory, particularly how people recall unfamiliar stories over time and whether they alter them to fit prior knowledge.

Context:
Schemas are simplified mental frameworks based on prior experiences and knowledge. When facing unfamiliar or strange information, people try to fit it into existing schemas, which may cause them to change or omit details, ultimately leading to inaccurate recall.

Procedure:
Bartlett had participants from Cambridge University read a Native American story called “The War of the Ghosts,” which involved unfamiliar cultural elements like supernatural events and seal hunting. Participants were asked to recall the story after 15 minutes, and at varying intervals afterward (e.g., weeks, months, years). Some retellings were repeated reproduction, others were serial reproduction (told from person to person).

Findings:
Participants remembered the general idea, but changed culturally unfamiliar elements to fit Western norms. Examples:

• “Canoe” was replaced with “kayak”

• “Hunting seals” became “fishing”

• Participants added phrases like “once upon a time” and invented morals

• Supernatural elements (like a black substance from the mouth) were omitted

• Retellings were shorter and more logical than the original story

Conclusion:
Findings supported schema theory: people unconsciously distorted unfamiliar material to make it fit existing cultural schemas. These schema-driven alterations allowed for easier recall but led to memory inaccuracy. This shows memory is not a passive recording device but a reconstructive process influenced by cultural expectations.

Mo & Mak (2009)

Hypothesis/Aim:
To investigate what determines people’s intention to seek mental health care in Hong Kong, using the Theory of Planned Behavior (TPB) as a framework.

Context:
The Theory of Planned Behavior states that attitudes, perceived social pressures (subjective norms), and perceived behavioral control predict whether someone intends to engage in a behavior. In many East Asian societies, stigma around mental health creates social barriers, so understanding what encourages or discourages mental health care use is vital.

Procedure:
Researchers randomly selected addresses from the Hong Kong Census and sent surveys to 941 participants, incentivized by a supermarket voucher. The participants (ages 18–65, equal gender split, 65% married/cohabiting, 30% post-secondary education) answered questions about:

• Their attitudes towards mental health care

• Perceived control over accessing services

• Social pressures or stigma

• Intentions to seek care

Findings:
People who had:

• Positive attitudes about the effectiveness and relevance of mental health care

• Low perceived stigma

• High confidence in overcoming obstacles
  were the most likely to seek care. Women and those with higher education levels were especially likely to express positive intent.

Conclusion:
Results supported TPB—intentions to seek mental health care were shaped by attitudes, social norms, and perceived control. Mo and Mak's findings help explain why certain demographics are more likely to seek help and can inform targeted interventions to reduce stigma and increase service access.

Tversky and Kahneman (1983)

Hypothesis/Aim:
To test whether people rely on the representativeness heuristic when making judgments and whether System 1 (fast, intuitive) thinking overrides System 2 (slow, logical) reasoning.

Context:
The Dual Process Model proposes two systems of decision-making:

• System 1: Fast, emotional, intuitive, low effort but prone to error.

• System 2: Slow, rational, logical, high effort but more accurate.
  People often use mental shortcuts (heuristics), especially representativeness, judging how likely something is based on how much it resembles a typical case.

Procedure:
88 university participants (undergrads = naïve, grad students = informed, PhDs = sophisticated) read a description of “Linda,” a 31-year-old philosophy major concerned with social justice, single, outspoken, and bright.
They were then asked to rate the likelihood of different professions for Linda, including:

• “Bank teller”

• “Bank teller and active in the feminist movement”

• “Bookstore worker”

• “Teacher”

Findings:
Nearly 90% of participants said Linda was more likely to be a “bank teller and feminist” than just a bank teller—a logical fallacy.
The conjunction of two events (bank teller + feminist) is always less likely than either one alone, but people ignored statistical probability and based their answer on how well Linda fit the feminist stereotype.

Conclusion:
Even highly educated people fell into the conjunction fallacy, showing how System 1 (representativeness heuristic) overrode System 2. This demonstrates how intuitive judgments can lead to irrational outcomes, supporting the Dual Process Model.

Kruger et al (2010)

Hypothesis/Aim:
To investigate the effort heuristic, a cognitive shortcut where people judge the quality or value of something based on how much effort they think was put into it.

Context:
Heuristics allow people to make fast decisions with minimal cognitive effort. However, they often lead to biases, especially when people focus on irrelevant factors. The effort heuristic suggests that we often judge something as better simply because it seems like it took more time or work to create.

Procedure:
Researchers conducted 3 experiments:

1. 144 psychology undergrads at Williams College read the same poem. Some were told it took 4 hours to write, others were told it took 18 hours. Participants rated its quality, how much they liked it, and how much money they would pay for it.

2. 33 Cornell undergrads viewed two abstract paintings ("12 Lines" and "Big Abstract"). One group was told "12 Lines" took 4 hours and "Big Abstract" took 26. Another group was told the reverse. They then rated both paintings on likability and monetary value.

3. 235 Illinois undergrads viewed 14 images of armor labeled with construction time. For the final image (a breastplate), participants were randomly told it took either 110 hours or 15 hours to make, and saw it in high or low resolution. They rated its quality and how much it was worth.

Findings:
In all 3 experiments, participants rated objects as higher quality and more valuable when they thought more effort was spent making them.

• In the poem experiment, the high-effort group gave it $45 more value on average.

• For the paintings, whichever one was said to have taken more time was rated more favorably.

• For the armor, both longer build time and higher image clarity led to higher ratings.

Conclusion:
People used the effort heuristic when making judgments about quality and value. Even though effort and actual quality were unrelated, people substituted perceived effort for actual merit, demonstrating how heuristics can lead to biased or inaccurate judgments.

Roediger & McDermott (1995)

Hypothesis/Aim:
To demonstrate how schemas and mental associations can lead to false memories through the process of reconstructive memory.

Context:
Memories are not recorded like a video; they are reconstructed each time we recall them. This reconstruction relies on engrams (memory traces) stored in different parts of the brain and is heavily influenced by schemas—our mental frameworks. These allow us to quickly process new information, but can also distort memory by filling in missing details with things that feel familiar.

Procedure:

• 36 undergrads at Rice University heard 6 lists of 15 words, each associated with a common theme or “schema.”

  • For example, a list might include “bed, tired, dream, nap…” but would omit the critical word “sleep.”

• After each list, they had 2 minutes to write down as many words as they could remember.

• Later, participants heard 12 previously heard words and 30 new ones, including:

  • 6 closely related lures

  • 12 somewhat related lures

  • 12 unrelated words
    They had to raise their hand if they thought each word had been in the original list.

Findings:

• Participants incorrectly recalled 40% of critical lures like “sleep” even though they were never presented.

• In the recognition task:

  • Only 8% falsely recognized unrelated words

  • 40% falsely recognized somewhat related words

  • 92% falsely recognized closely related lures
    These results show a strong correlation between the lure’s similarity to the schema and memory error.

Conclusion:
Memory is reconstructive and heavily influenced by schemas. When the mind fills in gaps, it often uses related concepts, leading to false recall. This demonstrates how easily false memories can form even in controlled settings, just by association.

Sharot et al (2007)

Hypothesis/Aim:
To investigate what distinguishes flashbulb memories from regular autobiographical memories, and what brain areas are activated when people recall traumatic, emotional events.

Context:
Flashbulb memories are vivid, detailed recollections of emotionally significant events (e.g., 9/11). They feel more accurate and long-lasting, but may still be subject to distortion over time. Emotion, especially trauma, is thought to enhance activity in the amygdala, the brain’s emotion processor, strengthening memory formation.

Procedure:

• 24 participants who were in New York during 9/11 underwent fMRI scans while recalling memories.

• During the scan, they saw the cue words “summer” (neutral) or “September” (intended to trigger 9/11).

• Afterwards, they wrote a description of the memory and rated it based on:

  • Arousal (emotional intensity)

  • Vividness

  • Reliving (how much they felt they were experiencing it again)

  • Confidence

  • Valence (emotional tone: positive/negative)

• Participants were grouped by location on 9/11:

  • Downtown Manhattan (near WTC)

  • Midtown Manhattan (farther away)

Findings:

• Downtown participants had higher arousal, vividness, and reliving ratings than Midtown participants.

• Their memory descriptions were longer, more emotional, and more negative in valence.

• fMRI scans showed greater left amygdala activity when Downtown participants recalled 9/11 than when they recalled neutral “summer” memories.

• Midtown participants showed no difference in amygdala activity between 9/11 and neutral memory recall.

Conclusion:
Flashbulb memories are not inherently more accurate, but they feel stronger when people have firsthand experience of traumatic events. Emotional intensity and personal relevance activate the amygdala, enhancing the vividness and emotional weight of the memory. This suggests that what makes a memory a “flashbulb” is the combination of emotional proximity and personal involvement, not just the event itself.

Milner et al (1968)

Hypothesis/Aim:
To investigate how localization of the brain affects function, specifically how the absence of the hippocampus affects memory, learning, and perception.

Context:
Localization is the idea that each part of the brain has a specific function. If a brain region is damaged, its associated behaviors or functions are affected. The hippocampus is linked to memory, learning, and understanding interactions and environments. This study followed Henry Molaison (H.M.), who had his hippocampus removed during a lobotomy to treat epilepsy.

Procedure:
Researchers conducted a series of problem-solving, perceptual, motor skill, and memory tests on H.M., fifteen years after his surgery.
Tasks included:

• Wisconsin Card Sorting Test: H.M. had to sort cards by rules that changed. He adapted well and didn’t repeat failed strategies—likely because he forgot his previous actions.

• Mooney Face-Perception Test: H.M. identified age and gender of fuzzy faces using schemas from before his surgery.

• Maze-learning tasks: H.M. could learn very simple paths and retain them for a few days, but barely improved on more complex mazes, even after 125 trials.

Findings:
H.M. could perform tasks that didn’t rely on new memory (e.g., schemas, procedures from before surgery), but could not form new long-term memories. His performance showed the hippocampus is crucial for declarative memory—retaining new facts and experiences.

Conclusion:
H.M.'s inability to form new declarative memories, despite performing well on perception and procedural tasks, showed the hippocampus plays a key role in memory formation, supporting the localization of function theory.

Maguire et al (2000)

Hypothesis/Aim:
To investigate whether structural differences exist in the hippocampi of taxi drivers due to their extensive spatial memory use and to explore neuroplasticity.

Context:
Neuroplasticity is the concept that structures in the brain can change over time due to environmental influences. Since different brain parts have specific functions, repeated use of certain skills may cause regions to grow. Taxi drivers need extensive spatial knowledge of London, often without GPS, relying heavily on the hippocampus, which stores spatial information.

Procedure:
Researchers used MRI scans to examine the brains of:

• 16 healthy, male taxi drivers (32–62 years old, 1.5–42 years of driving experience)

• 50 healthy, male non-drivers of similar age
  All were right-handed. Researchers compared hippocampal volume, focusing on anterior and posterior regions.

Findings:
Taxi drivers had larger hippocampi than non-drivers, specifically a larger posterior hippocampus (stores spatial info), but a smaller anterior hippocampus (conceptualizing spatial info).
The more experience a taxi driver had, the larger their posterior and smaller their anterior hippocampus became.

Conclusion:
The study supported neuroplasticity—the brain changes based on environment and repeated use. Taxi drivers’ spatial memory demands physically altered their hippocampal structures over time.

Guastella et al (2008)

Hypothesis/Aim:
To investigate how administering oxytocin to adult males affects their memory and social perception of faces.

Context:
Hormones are chemical messengers released by glands, influencing medium- and long-term behavior. Oxytocin, released through touch and bonding, is linked to trust, generosity, and social connection. It may affect how we process and remember emotional social information.

Procedure:
Researchers used a double-blind design and administered either oxytocin or a placebo via nasal spray to 69 men (ages 18–30).

• After 45 minutes, participants viewed 36 faces (happy, angry, or neutral) for 2 seconds each.

• The next day, they viewed 72 faces (36 old, 36 new) and indicated whether they “remembered,” “knew,” or “did not know” each face.

Findings:
Participants who received oxytocin were more likely to “remember” and/or “know” happy faces compared to angry or neutral ones.
There were no differences in recognition between the groups when shown new faces.

Conclusion:
Oxytocin affects how men process positive social cues, enhancing memory of happy expressions. It promotes trust, social bonding, and positive social memory, making it an influential hormone on behavior.

Kendler et al (2015)

Hypothesis/Aim:
To determine whether environment, rather than genetics, plays a greater role in determining cognitive ability (IQ) during adolescence.

Context:
Although cognitive ability is partially inherited, environment and socio-cultural influences play a significant role. Adoption studies allow researchers to compare siblings with similar genetic potential raised in different environments.

Procedure:
Researchers studied 436 sibships of 18–20 year olds from Sweden, where:

• At least one sibling was raised by biological parents

• The others were adopted
  Most biological parents were younger and less educated than adoptive ones.
  Researchers took IQ scores from military conscription data and had participants rate their parents’ education levels on a scale of 1 (lowest) to 5 (highest).

Findings:

• When adoptive parents had more education, adopted children scored on average 4.41 IQ points higher than their siblings raised by biological parents.

• When biological parents had more education, non-adopted siblings scored 3.8 IQ points higher.

• Each additional level of parental education correlated with a 2.73-point IQ boost in the child.

Conclusion:
Environment, specifically parental education and values toward learning, had a stronger impact on cognitive ability than genetics. During adolescence, nurture outweighed nature, and better-educated households contributed more to IQ development.

Fischer, Aron, Brown (2005)

Hypothesis/Aim:
To investigate the neural mechanisms of romantic love and see how dopamine-related areas of the brain respond when people see their romantic partner.

Context:
Neurotransmitters are chemical messengers that transmit signals in the brain. Dopamine is involved in pleasure, motivation, reward, and mood, and plays a role in romantic attachment and desire. Romantic love is thought to activate the brain’s reward system.

Procedure:
Researchers conducted fMRI scans on 17 participants (10 women, 7 men) who were in romantic relationships.

• During the scan, participants saw a picture of their partner and then counted down.

• Then they saw a picture of a neutral acquaintance and repeated the countdown.
  This cycle repeated six times.

Findings:
Viewing their partner, participants showed increased activity in the ventral tegmental area (VTA) and caudate nucleus, which are rich in dopamine and linked to reward and romantic attachment.
Participants who rated their relationship higher showed more brain activity.
Those in longer relationships had increased activity in the anterior cingulate cortex (ACC) and insula (emotion regulation and awareness), while those in shorter relationships had more activity in the posterior cingulate cortex (PCC) (early-stage attraction, self-relevant thought).

Conclusion:
Dopamine plays a key role in romantic love, activating reward and motivation regions. Brain activity also reveals how love changes over time—different areas are involved in early-stage passion versus long-term emotional regulation.

Taylor and Moriarty (1987)

Hypothesis/Aim:
To investigate how competition and group composition influence in-group and out-group bias, as explained by Social Identity Theory (SIT).

Context:
SIT states that people form in-groups and out-groups to define their identity. When people feel different from others, they emphasize loyalty to their own group, which can boost self-esteem but also lead to hostility and discrimination. These effects become stronger during competitive situations.

Procedure:
Researchers split 56 white female undergrads into groups of 4–6.
Each member completed two tasks:

1. A juvenile delinquent rehabilitation plan

2. A toothpaste advertisement slogan

Groups were randomly assigned to:

• A competition condition: solutions competed against another group, with a prize for the winner

• A cooperation condition: both groups’ solutions combined; if successful, both could win a prize
  Additionally, participants were told the out-group was either:

• Another group of white undergrads

• A group of Black students

Findings:

• In-group bias occurred in both conditions, but was stronger during competition

• Race of the out-group did not affect behavior—bias remained regardless of whether the other group was white or Black

• Even with minimal groups (4–6 people who barely interacted), participants still favored their own group

Conclusion:
Results supported Social Identity Theory. Competition intensified in-group bias, even without deep group connections. Race did not significantly affect bias, showing that group identity alone, especially under competition, is enough to create hostility.

Wedekind et al (1995)

Hypothesis/Aim:
To investigate whether women are more attracted to the smell of men with similar or dissimilar MHC (major histocompatibility complex) genes.

Context:
MHC genes help develop the immune system and allow the body to detect pathogens. A person with a more diverse set of MHC genes has a stronger immune system and is more biologically fit. Evolutionary theory suggests that people may be attracted to others with dissimilar MHC genes, as this could lead to offspring with more diverse and robust immune systems. Scent is one potential mechanism for detecting these genetic differences.

Procedure:

• 44 male students from the University of Bern were asked to wear a new 100% cotton T-shirt for 2 consecutive nights, avoiding deodorants, cologne, smoking, alcohol, and spicy food to preserve their natural body scent.

• 49 female participants (not on hormonal contraception) were asked to smell six T-shirts:

  • 3 from men with similar MHC genes

  • 3 from men with dissimilar MHC genes

• Women were tested during the second week after the start of menstruation, when scent sensitivity is highest.

• They rated the odors on a scale of 1 (least pleasant) to 10 (most pleasant).

• All participants had their MHC genes identified via blood samples.

Findings:

• Women rated the scents of men with dissimilar MHC genes as more pleasant.

• These scents also reminded women of their current or former romantic partners.

• An exception was found: women on hormonal contraception (in a follow-up study) preferred similar MHC scents, possibly due to hormonal interference with natural preference.

Conclusion:
Women are subconsciously more attracted to the body odor of men with dissimilar MHC genes, supporting the evolutionary idea that pheromones can influence mate selection in a way that promotes genetic diversity and immune system strength.

Wyart et al. (2007)

Hypothesis/Aim:
To investigate whether androstadienone (AND), a steroid compound found in male sweat and saliva, influences women’s mood, hormone levels (cortisol), and perception of male attractiveness, as would be expected of a human pheromone.

Context:
AND is thought to be a putative human pheromone. Past studies showed it activates brain regions linked to emotion and sexual behavior in a sex- and orientation-specific manner. Pheromones, by definition, must influence physiology and behavior, such as mood or hormone balance. Cortisol, a hormone involved in stress and arousal, was used as the physiological measure.

Procedure:

• 21 healthy, heterosexual women, who were:

  • Not using hormonal contraception

  • Free from chronic illnesses, medication use, anosmia (loss of smell), or nasal trauma

• Double-blind, repeated-measures design: Each woman participated in two sessions (AND and control), one week apart, at the same time of day.

• Testing occurred in a specially ventilated, stainless-steel scent room, monitored remotely by researchers.

Session Breakdown:

1. Baseline saliva sample collected

2. Participants watched a neutral nature video

3. A male experimenter entered and administered:

   • 30 mg solution of AND (in propylene glycol) or a control solution (yeast-based)

   • Each participant sniffed the solution 20 times

4. After administration, participants:

   • Watched three videos (sad, erotic, humorous – 5 mins each), separated by 10-minute neutral clips

   • Had 5 saliva samples collected throughout

5. Reported their mood before and after exposure, and rated male faces on attractiveness

Findings:

• Women exposed to AND:

  • Showed increased positive mood

  • Had higher cortisol levels, indicating hormonal arousal

  • Rated male faces as more attractive post-exposure

• Control condition (no AND) did not produce these effects

Conclusion:
AND may act as a pheromone-like compound by subtly increasing positive mood, hormonal arousal, and attraction to men. The presence of AND was associated with higher cortisol, suggesting it can alter endocrine balance—a defining feature of pheromonal influence.