EXAM 2
Chapter 6
Traits and Types: The Big Five and Beyond
The Point of Measuring Traits
Traits predict behavior
Traits can be used to understand behavior
What types of behaviors would be important to understand/predict
(Spoiler alert: it depends)
Research Methods Used to Connect Traits with Behavior
• Single-trait approach
• Many-trait approach
• Essential-trait approach
• Typological approach
The Single-Trait Approach
• What do people with a certain personality trait do?
– “What do people like that do?”
• Examine correlations between one trait and many behaviors
The Single-Trait Approach
• Self-monitoring
– It’s not necessarily better to be high or low
– Actors scored high and mental patients scored low
– Correlates with several behaviors
• You can see where you fit!
Where do you fit?
- I find it hard to imitate the behavior of other
people. T/F - At parties and social gatherings, I do not attempt to
do or say things that others will like T/F - I can only argue for ideas I already believe in T/F
- I can make impromptu speeches even on topics
about which I have almost no information T/F
The Single-Trait Approach
• Narcissism
– Charming, make good first impression
– Manipulative, overbearing, vain, and so on
– Many negative behaviors and attributes
• Aggression, argumentative,
– Why do they act like this?
– Not all of narcissism is bad…nor is it disordered
Food for thought
• Narcissism & Leadership
– (I’ll make the chapter available to
inspire Yellowdig posts)
The Many-Trait Approach
• Who does that important behavior?
– Examine correlations between one behavior and
many traits
• California Q-Set
– 100 personality descriptions
– Sort into a forced choice, symmetrical, and normal
distribution
– Compare characteristics within an individual
The Many-Trait Approach
• Word use
– Certainty words: related to being perceived as intelligent,
verbally fluent, turned to for advice, ambitious, generous
The Many-Trait Approach
• Political orientation
– Conservative: favor values of in-group loyalty, authority and respect, and purity; and less able to handle stress well as children
– Liberal: favor values of reduction of harm & fairness; independent & confident as children
– Authoritarian: strongest in value of respect for authority/prefer strong leaders, uncooperative and inflexible, likely to obey a command to harm others, fewer positive emotions
The Essential-Trait Approach
• Which traits are the most important? Which traits really matter?
• Theoretical approaches to reducing the many to a few
– Murray: 20 needs
– Block: ego-control and ego-resiliency
The Essential-Trait Approach
• Factor analytic approaches to reducing the many to a few
– Cattell: 16 essential traits
– Eysenck: extraversion, neuroticism, psychoticism
– Tellegen: positive emotionality, negative emotionality, constraint
The Essential-Trait Approach:
The Big Five and Beyond
• Discovery of the Big Five
– Factor analysis
– Other personality tests tend to fit the Big Five groups
• Lexical hypothesis
– Look for traits that have the most words and are the most universal
The Essential-Trait Approach:
The Big Five and Beyond
• Implications of the Big Five
– Can bring order to many research findings
– Traits are (theoretically) orthogonal, or unrelated
– More complex than they seem at first
• Not entirely orthogonal (independent)
• Higher-order factors: stability and plasticity
– More stable: Agreeableness, Conscientiousness, & (Low)
Neuroticism
– More plastic: Extraversion & Openness
• Lower-order factors or facets
The Essential-Trait Approach:
The Big Five and Beyond
• Universality of the Big Five
– When translated to other languages, four or five of the factors appear
• Support – Lexical Hypothesis
– When starting with other languages: some overlap but not one-to-one correspondence
– Scores vary by geographic region
The Essential-Trait Approach:
The Big Five and Beyond
• Beyond the Big Five (criticisms)
– There is more to personality
– Too broad for conceptual understanding
• Doesn’t give us information about the “type” of person someone is
Typological Approach to Personality
• Based on doubt about whether it is valid to compare people quantitatively on the same trait dimensions
– Important differences between people may be qualitative
• Challenges: find divisions that distinguish different types; show differences are qualitative
Examples
• Empirical
– Myers-Briggs Type Indicator
– Poor validity
• Muhammad Ali’s
Implicit Theory
– Personalities as fruits:
– Poor Validity
Typological Approach: The MyersBriggs Type Indicator (1)
• Used in workplaces, schools, counseling centers, management workshops, etc.
• A big business
• Four opposing tendencies:
o Extroversion (E) vs. Introversion (I)
o Sensing (S) vs. Intuition (N)
o Thinking (T) vs. Feeling (F)
o Judgment (J) vs. Perception (P)
• 16 possible personality types
Typological Approach: The MyersBriggs Type Indicator (2)
• Reasons for popularity
– Offers seemingly rich and intriguing descriptions
of each personality type
– Looks insightful
– All types are explained positively.
– People think learning their type is enjoyable
Typological Approach: The MyersBriggs Type Indicator (3)
• Criticisms
– Not useful for selection or predicting life outcomes
– Based on normally distributed scores
– Measurement is not reliable
– No evidence that different types follow, persist in, or succeed in different lines of work
Myers-Briggs VS Horoscope
Typological Approach to Personality
• Three replicable types
– Well adjusted
– Maladjusted overcontrolling
– Maladjusted undercontrolling
• But types do not predict behavior beyond what can be predicted with traditional trait Scores
Recent research on Types
• A typological approach…rooted in the Big 5
– Gerlach, Farb, Revelle, Nunes, & Amaral (2018)
• Washington Post Article
• Four types of people
– Reserved
– Role Model
– Self-Centered
– “Average”
Typological Approach to Personality
• Is it useful to think about people in terms of types?
– Yes (maybe)
– Summary of standing on several traits
– Makes it easier to think about how traits within a
person interact with each other
– But doesn’t add up to ability to predict outcomes
• (as of now)
Can personality predict behavior over a lifespan?
Chapter 7 Personality Stability, Development, and Change
Think carefully…
How have you changed over the last
5 years?
How have you stayed the same?
How do you think you might change
in the future?
What is our reference point?
Are we evaluating our personality as an individual? Or are we evaluating our personalities against our peers?
Rank-order consistency: the maintenance of individual differences in behavior or personality over time or across situations
But what does this actually mean?
Two Types of Continuity –
Caspi 1998
Absolute Continuity
“When taking the MBTI (MyersBriggs Type Indicator), Dr. Ed scores high in
Extraversion”
Differential Continuity
-Dr. Ed was extraverted when he in college, and he is extraverted
Now This continuity is relative to peers
▪ This can still change over time when examining only the individual
Interpreting Correlations
Survey 100 people when they are age 18 & 28
Ex: Extraversion at 18 correlates with extraversion at 28
r = .80, p < .001
Absolute or differential continuity?
Strong DIFFERENTIAL continuity
Absolute vs. Differential
Continuity
Take our example
Strong correlation, but Extraversion still might have gone DOWN on average
Strong Diff-Cont
Weaker Abs-Cont
2007
2017 Person1 10 7
Person2 8 5
Person 3 9 6
Person4 6 3
Person5 5 2
Person6 4 1
Average: 7.0 4.0
Differential Continuity
Absolute continuity isn’t measured as often
We tend to compare differences among
people who are the same age
AKA: heterotypic continuity
Continuity in behaviors varies with age
Ex: shy adults do not hide behind their parents when meeting new people, but shy children do
Personalities do change over time
Some traits are more consistent than others
Conscientiousness
Neuroticism
▪ Gradual decrease Openness
▪ Gradual increase Extraversion
▪ Decrease early in life
Personality Changes Across
Cohorts
Women’s assertiveness depends greatly on when they were born
Twenge (2000, 2001)
Narcissism & Anxiety – we’ve discussed this Twenge (2000, 2008)
Overall
High differential continuity throughout adulthood
In general, the larger the gap, the lower the continuity
Ex: Neuroticism
▪ 6 year gap – r = .83 (Costa & McCrae, 1988)
▪ 10 year gap – r = .67 (Costa & McCrae, 1978)
▪ 16 year gap – r = .66 (Helson & Moane, 1987)
▪ 18 year gap – r = .46 (Conley, 1985)
▪ 30 year gap – r = .56 (Finn, 1986)
When is the earliest we can learn about a person’s personality?
Temperament = early-appearing, stable individual differences in reactivity & self regulation
Reactivity - quickness & intensity of emotional arousal, attention, and motor action
Self-regulation – strategies that modify reactivity
Cornerstone of personality
Thomas & Chess’ New York
Longitudinal Study (1956)
First influential model
Followed 141 children from early infancy into adulthood
Impacts psychological adjustment
Increase chances of psych problems OR
Protect from neg effects of stress
Parenting practices
Structure of Temperament
Easy – 40%
Adapts easily, cheerful
Difficult – 10%
Slow to accept new experiences, neg & intense reactions
Future risk
Slow-to-warm-up – 15%
Adjusts slowly to new
experiences, inactive & fearful
Unclassified – 35%
Temperament and Modern Perspectives
We’re no longer as likely to group children into categories
Between-person approach
Now, researchers analyze children on various temperament dimensions
Within-person approach
Dr. Mary Rothbart
University of Oregon
Rothbart & Bates’ (2006) –
3 dimensions
Extraversion/surgency
Positive anticipation, impulsivity, activity level, sensation seeking
Negative affectivity
Fear, frustration, sadness, discomfort
Effortful control (self-regulation)
Attentional focusing/shifting, inhibitory control, perceptual sensitivity, low intensity pleasure
BASED ON Rothbart et al., 2001; Gartsein & Rothbart, 2003, Rothbart et al.,
2004
Sample items for Infants and
Children
“How often during the last week did the baby startle to a sudden or loud noise?”
“My child is not afraid of large dogs and/or other animals.”
“When put into the bath water, how often did the baby splash or kick?
“My child seems always in a big hurry to get from one place to another.”
Stability of Temperaments
During Infancy
Stability of temperament is higher over short intervals of time than over long intervals of time
Level of stability of temperament increases as infants mature
Stability of Temperament during
childhood
Develops with age
Overall, low to moderate stability
Better after age 3
▪ Emotion, attention, and action better
established
▪ Brain development – frontal lobes
Effects of Temperament on
One’s Environment
Selection
People choose situations that match their personality
Manipulation
People change situations to be congruent with their personality
Evocation
Personality differences evoke different reactions from others
Shared vs Nonshared
Environmental Influences -
SIBLINGS
Shared: Features shared by siblings
Parental Values
Socio-Economic Status (SES)
Nonshared: Features that differ for
siblings
Friends and teachers
Activities and hobbies
Birth order
Types of Unique Sibling Experiences
Random Experiences that occur outside of the family:
School, Peers, Athletics, Hobbies, etc.
Systematic Influences related to one’s ordinal position (i.e., birth order) within the family.
Relative Age
Power (physical, intellectual, etc.)
Privilege within the Family
Family Size
Influences on IQ
Shared Environment MATTERS
Correlation among adoptive siblings is .32
Non shared influences
Birth order
Historical note:
Adler’s Views on Birth Order
Siblings compete for parental resources
Attention, affection, etc.
1st born child is “dethroned” by later siblings
Cope by emulating parents
Over emphasize rules and order
Become “power hungry conservatives”
Correlations Related to Birth Order and IQ
1st born children
Talk earlier and more clearly
Learn to read earlier
Perform better on problem solving tasks
Higher achievers in school
Score higher on IQ tests
IQ study of 400,000 Danish children
IQ declines with birth order
IQ declines with family size
Birth Order and IQ
Possible Explanations
Differential parental treatment
Parents have less experience/greater expectations for 1st born children
More time spent on intellectual tasks
Quality of intellectual environment
Later born / children from larger families spend more time interacting with kids
Older children act as teachers
Mutual benefit to the teacher and the learner
A few findings related to birth-order
Younger siblings tend to show higher levels of openness, agreeableness, and extraversion
Older siblings tend to show higher conscientiousness
Sulloway, 2010
Adler wasn’t all wrong: “Later born children must compete with 1st born
children”
Face size/developmental differences
Must become more cooperative
Adolescent Egocentrism:
The Personal Fable (Elkind, 1981)
Characteristic of adolescent thinking that leads young people to focus on themselves to the exclusion of others.
Young person might believe his or her thoughts, feelings, and experiences are unique.
Ex: “You can’t possibly understand how I feel, MOM! This is different!!” But this script is a rough draft
Types of Scripts
Commitment scripts
Long-term investment towards improvement
Think of a positive scene from your childhood
A vision/ideal of what “could be”
Absence of conflict – overconfidence?
Nuclear scripts
“Sh*t gets real”
Complex
Avoidance/approach conflicts
Sometimes, these scripts/scenes inspire change in our personalities
Desire for change is typical, and usually in the socially desirable direction
Neuroticism is what people wanted to change the most
Agreeableness is what people wanted to change the least
Ex: Extraversion
2 = much more
1 = more
0 = the same
-1 = less
-2 = much less
Try for yourself on
p.239
Hudson & Roberts, 201
Let’s no
Let’s not forget about
the introverts in the room!
Introversion has gotten a lot of attention the last decade or so
Can be a strength in ways many people underestimate
Susan Cain – TED Talk
Alternate version of
I/E trait test
Quiet Revolution
Let’s look at a couple items
I don’t take risks unless I’ve done some careful research or evaluation first.
A. Very uncharacteristic or untrue, strongly
disagree
B. Uncharacteristic
C. Neutral
D. Characteristic
E. Very characteristic or true, strongly agree
I quickly feel drained when in a
large crowd of people.
A. Very uncharacteristic or untrue, strongly
disagree
B. Uncharacteristic
C. Neutral
D. Characteristic
E. Very characteristic or true, strongly agree
4 Potential Methods for
Changing Personality
Psychotherapy and psychiatric drugs
General interventions
Targeted (specific) interventions
Behaviors and life experiences
Personality Change
Psychotherapy and psychiatric drugs
Why would this be necessary?
General interventions: usually aimed at important outcomes
Personality Change
Targeted interventions: addressing specific personality traits/behaviors
Increasing self-control: relaxation, learning to think differently about temptations and frustrations, mindfulness meditation, set realistic goals that are compatible with personal values
Personality Change
Behaviors and life experiences
Positive: exercise, starting college or a job, beginning a serious relationship
Negative: trying drugs, onset of chronic disease
Becoming unemployed
Negative life events
Travel
Military training
Personality Change
Obstacles to change
Not seeing a reason for change
Takes effort
Blaming negative experiences and failures on external forces
People like consistency and predictability
If you DO want to change
Who do you want to be?
How is that person different from the one you are now?
What can you do (TODAY) to make this change start to happen?
Chapter 8-The Anatomy and Physiology of Personality
LET’S START WITH A CASE STUDY
• Does anyone in class recognize the name Charles Whitman?
• What about now?
• On August 1, 1966, Charles Whitman climbed to the top of a tower on the campus at UT-Austin and began shooting
• One of the earliest, deadliest massshootings in American history
• Also killed his wife and mother
• “After my death I wish that an autopsy would be performed on me … I cannot rationally pinpoint any specific reason for doing this”
– Charles Whitman, the day before the shooting
THEY FOUND A TUMOR
• Located near the amygdala…
• More questions than answers
• Assuming that the tumor was affecting his brain functioning, was Whitman aware of desires to kill?
• Was he in control of the desires?
• Had Whitman been captured and not killed, and
you were on a jury trying him, would you have
found him guilty or not guilty?
• Of course, this is not the only case study we
know that indicates brain structure is related to
personality
BRAIN DAMAGE - PHINEAS GAGE
• Railroad worker injured by misuse
of gunpowder
• Rod went through frontal lobe
• Attitude changed
• Pre-accident: Hard-working, responsible
and popular
• Post-accident: Impatient, stubborn,
vulgar and spontaneous.
HOW DO WE KNOW WHAT THE BRAIN IS
DOING?
- Dissection (post mortem examination of brain
structures)
• Ex: Whitman - Study brain damage
• Ex: Gage - Activating the brain
- Monitoring the brain in action
I COULD SHOW YOU A RELATIVELY
GROSS VIDEO HERE…BUT I’M NOT
• Electrical stimuli can activate neuron firing when applied to specific parts
of the brain
• Fortunately, we have other approaches
• Transcranial magnetic stimulation (TMS
TECHNIQUES FOR MONITORING THE
BRAIN IN ACTION
• Electroencephalograph (EEG)
• Computerized Tomography Scan (CT Scan)
• Positron Emission Tomography (PET)
• Magnetic Resonance Imaging (MRI)
• Functional Magnetic Resonance Imaging (fMRI)
• Neurotransmitters
ELECTROENCEPHALOGRAPH (EEG)
• Measures gross electrical activity
of brain
• Reports brain waves during
activities (like sleeping)
COMPUTERIZED TOMOGRAPHY SCAN (CT SCAN)
• Like an x-ray of the brain
• Used to detect tumors or
injuries
POSITRON EMISSION TOMOGRAPHY
(PET)
• Patient ingests
harmless
radioactive
substance (a
sugar!) that travels
to the brain
• Areas of the brain
that are working
will absorb more of
this substance and
“light up”
MAGNETIC RESONANCE IMAGING (MRI)
• Uses magnets to look at the
structure of the brain.
• Produces 3-D pictures of the
brain that are extremely
detailed
FUNCTIONAL MAGNETIC RESONANCE
IMAGING (FMRI)
• Also creates a detailed 3-D
image on the brain
• Measures oxygen in blood in
the brain to determine
activity
MRI VS FMRI
MRI studies Brain Anatomy
fMRI studies Braid Function
PROCEED WITH CAUTION
• What happens in the brain when you show a
subject emotional vs. non-emotional scenes?
• What if the subject is a salmon?
• A salmon that happens to be dead?
• Brain activity!
• Bennet, et al. (2010)
THE ANATOMY OF PERSONALITY: RESEARCH
METHODS FOR STUDYING THE BRAIN
• Difficulties with imaging techniques
• May indicate inhibitory activity
• All parts of the brain are always active to some degree
• Blood oxygenation level dependent (BOLD) imaging signals
and perfusion imaging
• Brain activity in response to a stimulus does not mean the same
psychological process occurs every time that area is active
HIGH SS VS LOW SS BRAINS
• Remember when we said that people high in
extraversion were less responsive to punishment
in gambling?
• Here, we see the same pattern in High vs. Low
Sensation Seekers
• Both High SS’s and Low SS’s participants
respond to rewards (“Win”)
• More activation after punishment (“No Win”) in
the brains of High SS’s * than in the brains of
Low SS’s **
SENSATION SEEKING – REVIEW
• “The need for varied, novel, and complex sensations and experiences and
the willingness to take physical and social risks for the sake of such
experiences” (Zuckerman, 1979, p. 10)
• Can you describe it in your own words?
NEUROPSYCHOLOGY
OF SENSATION SEEKING
• Monoamine oxidase (MAO) – enzyme that helps
regulate the level of neurotransmitters in the body
by breaking down the NTs
• Sensation seekers tend to have low levels of MAO in
their bloodstream
• Which NTs might be more prevalent for sensation
seekers?
• Dopamine
• Epinephrine/norepinephrine
BIOCHEMISTRY AND PERSONALITY: NEUROTRANSMITTERS
• Dopamine
• Possible relation with bipolar disorder,
extraversion, and impulsivity
• Individual differences in development of nerve
cells that produce and are responsive to
dopamine
• Activates the behavioral activation system
(BAS)
BAS/BIS DISTINCTION
• Behavioral Activation System (Gray 1982, 1987)
vs.
Behavioral Inhibition System (Gray, 1987)
• Approach vs. Avoidance
• Which “Big 5” trait do you think is more associated
with BIS?
• NEUROTOCISM
TWO ASPECTS OF THE BRAIN THAT CAN
BE EXAMINED WITH TECHNOLOGY
• Anatomy: functions of parts of the brain
• Biochemistry: effects of neurotransmitters and hormones on brain
processes
• Both are related to personality and behavior
• Both have been used to TREAT
abnormal psychology as well
THE ANATOMY OF PERSONALITY:
THE LESSONS OF PSYCHOSURGERY
• Prefrontal leucotomy (by 1937)
• Prefrontal lobotomy—more drastic
• Observations of patients consistent
with brain damage
• Replaced with drugs
• Is this better?
TED TALK
• Sometimes, we don’t know why a treatment works
AN ALTERNATE APPROACH
• Amazingly, deep transcranial magnetic stimulation has ALSO shown
tremendous promise for people suffering from severe depression!
UPDATE!
• FDA Clears SAINT Rapid-Acting
Brain Stimulation Approach fo
r Those Suffering From Resista
nt Major Depression
• This approval only happened
on September 6th, 2022
• Very exciting to see what
happens next!
THE BIOCHEMISTRY OF
PERSONALITY
• Galen (Rome, A.D. 130–200) proposed that
personality depended on the balance of humors
(blood, black bile, yellow bile, phlegm)
• The chemistry of the mind
• Neurons communicate with neurotransmitters
• Hormones stimulate or inhibit neural activity
• About 60 chemicals transmit information in the brain
and body
• People differ in average levels
THE BIOCHEMISTRY OF PERSONALITY:
NEUROTRANSMITTERS
• Dopamine
• Involved in responding to reward and approaching attractive objects and
people
• Related to sociability, general activity level, and novelty seeking
• Parkinson’s disease
• Serotonin
• Depression
THE BIOCHEMISTRY OF PERSONALITY:
SEROTONIN (AND PROZAC)
• Prozac: a selective serotonin reuptake inhibitor
(SSRI)
• Physical effect: increases serotonin levels
• Changes in personality for people without a
diagnosed disorder
• Makes negative emotions less severe and
doesn’t affect positive emotions
THE BIOCHEMISTRY OF
PERSONALITY: HORMONES
• Testosterone
• Concentration in men is about 10 times higher than in women
• Link with aggression is complex
• Role in control and inhibition of aggression and sexuality
• Related to many other behaviors
• Unknown causal direction
THE BIOCHEMISTRY OF
PERSONALITY: HORMONES
• Cortisol
• Released in response to stress
• Chronically high levels in people with
severe stress, anxiety, and depression
• Low levels related to post-traumatic
stress disorder (PTSD) and sensation
seeking
THE BIOCHEMISTRY OF
PERSONALITY: HORMONES
• Oxytocin
• Role in mother-child bonding, romantic attachment, and sexual response
• Decreases fearfulness
• Facilitates approach behaviors
THE BIG FIVE AND THE BRAIN
• Relationships between personality,
brain anatomy, neurotransmitters,
and hormones are complex
• Ex: Stability is associated with
serotonin and plasticity is associated
with dopamine
• Figure 8.14, p.304
• but you don’t need to
memorize these
BIOLOGY: CAUSE AND EFFECT
• “The relationship between the brain and its environment works in both
directions”
(p. 298)
• Understanding the brain can help us understand behavior, but
understanding behavior can also help us understand the brain
• Remember how sensation seekers are likely to have less MAO?
• Serial killers also show differences in the related MAOA gene,
But they must experience trauma for the gene to be activated
• Ted Talk – Exploring the Mind of a Killer, Jim Fallon
Chapter 9 Genetics and Evolution: The Inheritance of Personality
Understanding human nature
Why do people act the way they do?
What motivates someone to act the way they do?
How have we evolved to think and
behave the way we do?
– Evolutionary psychology
Genes, Behavior, & Evolution
We’ll get to genes soon…
Evolutionary Psychology – the study of the evolution of cognition and
behavior using principles of natural selection
Who can give a good definition of what natural selection is?
Charles Darwin - Natural
selection
Natural selection:
– The process whereby nature
gradually selects those
characteristics of organisms
that promote survival and
reproductive success
Classic Example:
Physical Characteristics
Long-necked (LN) giraffes
Short-necked (SN) giraffes
Who could reach more leaves on the
trees?
– LN giraffes
LN giraffes were more likely to survive
(more food)
– Offspring with long-necks
Relatable Example:
Halloween Candy
Imagine I have a giant bowl of candy
(alas, I do not)
Which traits or
characteristics will
you look for in the candy you select
– Desirable candy
More likely to be selected/
pass on genes
– Undesirable candy
Dies childless and alone…
So how can we tell if something is an
evolutionary adaptation?
Difficult to test empirically!
Some will be specific to individual
cultures/species
The most basic (and potentially most
important) behaviors/traits should
show up cross-culturally
– Let’s evaluate some evolutionary
hypotheses
Read my lips
The “Universality” of emotions?
– Happiness (A)
– Sadness (B)
– Surprise
– Fear
– Disgust (C)
– Anger
– Contempt*
Why would this be
beneficial?
Emotions & Survival
The anger superiority effect
– We recognize ANGER faster than any of
the other emotions
Specific ways recognizing emotions
can be adaptive
– Preparation for action – fight or flight?
– Is this person someone I can trust?
Babies also attend more to smiling (safe)
Faces
How good are you
at recognizing emotions?
16-year-old participants misidentify
this emotion 75% of the time
Some of you did
better than others
Implications for survival
– Ex: Lie detection, safety, etc.
Fortunately, you all have lots of OTHER
attributes that contribute to your inclusive
fitness
“An organism’s overall (total, inclusive)
ability to maximize the replication of the
genes that designed it”
McAdams, 2009, p. 35
Conclusions?
So, does this mean that facial
expressions/emotions are
universal/evolutionary adaptations?
– Spoiler alert:
IT DEPENDS
– Context matters
Example 2:
Why do we help each other?
From an evolutionary standpoint,
why would altruism occur?
– Kin selection – family first!
– Helping others (outside of our family
tree) will not help us survive or help
pass on our genes
Does “true altruism” exist?
– Many psychologists say NO
– What do you get in return?
West, Whitney, & Schnedler,
1975
Researchers posed as
motorists in distress trying to
flag passing cars to provide
help with a flat tire
– Cars were MUCH more likely to
stop for a woman than for a
man
– Most of the cars that stopped
were driven by young men who
were driving alone
Feeling good about ourselves…
and feelings in general
Besides sexual motives, we will often
help others to change or maintain our
positive mood
– Helping others can make us feel good in
return
Can anyone think of other factors that
might make a person more/less likely
to help someone?
– Personality
– Culture
– Others
Reasons for helping
They will help you someday
You want to feel good about yourself
You want other people to think you
are a good person
ALL OF THESE INCLUDE SOCIAL
EXCHANGE
What do we get back?
Reciprocal Altruism
– Trivers (1971)
Early hunter/gatherer societies
– Sharing resources with hopes of
receiving help at another time
– Mutual benefit to be helpful to nonrelative others
Moving on…
To understand why individuals act
the way they do, you must first
understand human nature and
evolutionary psychology
– Plenty of other traits/behaviors
E.g. Aggression
– Cross-cultural evidence is key
We cannot forget about genes
Genetics
99% of all human genes are identical
– 98% shared with chimpanzees (Balter,
2002)
How can we differentiate between
effects related to Nature vs. Nurture?
Twins are studied here at FSU
The Florida State Twin Registry
– Established in 2002/03 by Dr. Jeanette
Taylor (previous department chair)
Other collaborators in the dept:
– Dr. Chris Schatschneider
– Dr. Richard Wagner
– Dr. Sara Hart
So, why are twins so important?
Identical vs. Fraternal Twins
Monozygotic (MZ) versus dizygotic (DZ)
twins
– In other words, ONE or TWO zygotes
Heritability quotient
Difference between correlation (r) for
MZ and DZ twins
(rMZ – rDZ) x 2
Calculating Heritability
Heritability coefficients from twin
studies ≈ .40
Heritability coefficients from nontwin studies ≈ .20
Difference suggests that the effects
of genes are interactive and
multiplicative
Behavior Genetics
Many traits/behaviors have genetic links,
but environment (pre- AND post-natal)
matters
Environment-gene interactions
Epigenetics: experience affects biology
– May be possible to help people find
environments that will lead to good outcomes
“How your genes shape who you are” - BBC
Want to learn more about it?
– “Lick your rats” lab website
Anxiety can be genetic, but rat pups
that were nurtured (aka: licked/
cleaned) by their mothers grew
up to be more calm & less anxious
Weaver, et al., 2004
Individuals can also change
their environment
Evocative person-environment
transaction (p-et)
– Likely to create/experience hostile
environments
Reactive p-et
– Less likely to create their environment
than to react to it
Active p-et
– Selecting/creating compatible environments
Behavioral Genetics
The future
– Genes have important influences on
personality
– Researchers are working to find out which
genes are dependably associated with
personality
– The big picture will be complicated
Inheritance is the beginning…not the end