personality: cultural and biological approaches

What is culture?

The shared beliefs, customs, traditions, and art of a particular society.

Why is culture important in personality development?

It is one of the strongest environmental influences shaping how people think, behave, and interact.

Are personality traits universal across cultures?

Both are true:

✔ Some traits are universal
✔ Some are culture-specific

What is individualism?

A cultural value emphasizing:

• Independence

• Personal achievement

• Competition

What is collectivism?

A cultural value emphasizing:

• Social harmony

• Respectfulness

• Group needs over individual desires

What motivates people in collectivist cultures?

Acting in ways that benefit the group and avoid bringing shame.

Who was a major researcher on individualism vs collectivism?

Harry Triandis

What does WEIRD stand for?

• Western

• Educated

• Industrialized

• Rich

• Democratic

Why is WEIRD research considered a limitation?

Because most psychology studies rely on a very small and unrepresentative portion of the world.

About 96% of studies use only 12% of the population.

What did the massive cross-cultural study find?

Across:

• 17,000 participants

• 28 languages

• 56 countries

The Big Five traits were consistently found.

What does this global research suggest about personality?

Personality has a biological foundation, but culture shapes how traits are expressed.

What is a major limitation of the Big Five model?

It was developed using English personality adjectives, which may not fully capture personality traits in other languages or cultures.

What happened when researchers analyzed personality in Chinese?

They found a different structure — the Big Four, not the Big Five.

What are the four personality factors found in Chinese research?

• Dependability

• Social potency

• Individualism

• Interpersonal relatedness

What does the Chinese Big Four suggest about personality models?

Personality structure may be partly culture-specific, not completely universal.

Give examples of common national personality stereotypes.

• Italians → passionate

• Swiss → punctual

• Germans → organized

• Canadians → polite

What does research say about “national character”?

There is no convincing evidence that entire nations share one personality.

Give examples of response style differences.

Some cultures avoid saying “no.”
✔ Self-promotion may be normal in North America but seen as boastful elsewhere.

What did Rentfrow et al. (2013) discover?

Three major personality clusters in the United States.

What traits characterize each U.S. region?

Upper Midwest & Deep South:
Friendly, conventional

West:
Relaxed, emotionally stable, creative

Northeast:
More stressed, irritable, depressed

What explains regional personality differences?

• Selective migration

• Founding cultures

• Climate

What is the biggest challenge in studying personality across cultures?

Separating true personality differences from cultural measurement bias.

What is temperament?

Inborn, biologically based personality tendencies visible early in life.

What are the three infant temperament types?

Easy – adaptable, calm, regular routines
✔Difficult – irritable, unpredictable
Slow-to-warm-up – cautious, adjusts gradually

Does temperament fully determine adult personality?

No — environment and maturation influence how personality develops.

What is reactivity?

How strongly someone responds to new or challenging stimuli.

What is self-regulation?

The ability to control emotional and behavioral responses.

Why is the Minnesota Twin Study important?

It provided strong evidence that genes significantly influence personality.

What was the major finding of twins raised apart?

Identical twins raised in different homes were about as similar as those raised together.

How did identical twins compare to fraternal twins?

✔ Identical twins raised apart → very similar
✔ Fraternal twins raised together → more different

What do twin studies show about the Big Five traits?

Each trait shows a genetic basis, with higher similarity in identical twins.

If personality is genetic, do parents still influence development?

YES.

Examples:

✔ Attachment styles
✔ Support and encouragement
✔ Abuse or trauma

How do genes influence personality?

Genes code for brain proteins that affect behavior, emotional responses, and temperament.

What is the 5-HTT gene?

A gene related to serotonin transport, which affects mood and stress responses.

What are the two versions (alleles) of the 5-HTT gene?

✔ Short allele
✔ Long allele

What personality traits are associated with the SHORT allele?

• Higher anxiety

• Greater shyness

• Increased neuroticism

• More attention to threats

What traits are linked to the LONG allele?

• Less reactive to stress

• More focus on positive stimuli

• Better emotional regulation

What did the eye-tracking study reveal about anxiety and genes?

✔ People with 1–2 short alleles looked longer at negative images.
✔ People with 2 long alleles avoided negative images and focused on positive ones.

How might the 5-HTT gene affect relationships?

Individuals with the short allele tend to be more emotionally sensitive, meaning:

• Bad marriages feel worse

• Good marriages feel better

Do genes directly cause personality traits?

No — most studies are correlational, not causal.

Do single genes usually cause psychological disorders?

No — most traits result from multiple genes interacting with the environment.

What is genetic epigenesis?

The process by which environmental experiences turn genes on or off.

Can these gene changes be passed to future generations?

Yes — some epigenetic effects can be inherited.

Why do psychologists study personality in animals?

To understand the evolutionary origins of personality traits.

What personality types were found in birds (Parus major)?

• Fast-exploring → bold

• Slow-exploring → shy

Each can be advantageous depending on resources.

Which Big Five traits appear in chimpanzees?

✔ Extraversion
✔ Conscientiousness
✔ Agreeableness

Do other animals show personality differences?

Yes!

Why are there so many different personality traits?

Because personality diversity is evolutionarily adaptive.

What are core human traits seen across cultures?

Humans tend to:

• Form social groups

• Develop language

• Work

• Play

Why are “dark” traits maintained in the population?

Because they can sometimes be evolutionarily successful.

Example advantages:

• Manipulation → gaining resources

• Aggression → dominance

• Narcissism → attracting attention/status

Why is personality diversity beneficial for groups?

Different personalities allow groups to adapt to changing environments.

Example:

✔ Risk-takers explore
✔ Cautious individuals protect

Do men and women have dramatically different personalities?

No — variation within genders is MUCH greater than variation between them.

which traits do women tend to report slightly higher?

• Extraversion

• Conscientiousness

• Agreeableness

• Neuroticism

What influences the size of gender differences?

Resource availability.

Countries with more wealth, education, and healthcare show larger differences because people can express individuality.

Less resourced countries → fewer differences.

What were the four humours?

Ancient theory that personality came from body fluids:

• Blood

• Yellow bile

• Black bile

• Phlegm

Example of humour personality type?

Sanguine → optimistic and social

What was phrenology?

The belief that personality could be determined by measuring bumps on the skull.

Developed by Franz Gall.

Why was phrenology harmful?

It was used to justify white supremacy and is now completely discredited.

What did the Eysencks focus on?

The biological and genetic basis of personality.

What two traits explain personality variation according to Eysenck?

Extraversion ↔ Introversion
Neuroticism ↔ Emotional Stability

Why do extraverts seek stimulation?

they have lower baseline brain arousal, so they look for excitement.

Why do introverts avoid too much stimulation?

They already have higher brain arousal, so extra stimulation feels overwhelming.

Who was Jeffrey Gray?

A student of Eysenck who refined the biological explanation of personality.

What is Reinforcement Sensitivity Theory (RST)?

A theory proposing that personality differences are based on how sensitive people are to rewards vs punishments.

How is extraversion explained in RST?

Extraverts are more sensitive to rewards.

How is neuroticism explained in RST?

Highly sensitive to punishment and threat.

What is the BAS?

The brain’s “GO system” that motivates action toward rewards.

What is the BIS?

The brain’s danger-detection system that motivates avoidance of negative outcomes.

Which neurotransmitter is most associated with reward and thrill-seeking?

Dopamine

What is acetylcholine (ACh) responsible for?

• Arousal

• Memory

What is serotonin (5-HT) linked to?

• Mood

• Sleep

What does norepinephrine (NE) regulate?

Wakefulness

Have scientists successfully mapped the Big Five onto brain structure?

Only limited success.

How do extraverts differ neurologically from introverts?

LESS activity in the amygdala
MORE activity in the medial orbitofrontal cortex (dopamine/reward)

What thinking pattern is common in highly neurotic individuals?

Obsessive negative thinking and heightened sensitivity to mistakes.

What does the dorsomedial prefrontal cortex do?

Helps regulate emotions.

What is the role of the hippocampus?

• Memory

• Helps control repetitive negative thoughts

What does the mid-cingulate gyrus detect?

• Errors

• Pain