NATURE VS NURTURE
Fundamental Question
To what
extent are
we shaped
by our
heredity
and
life history?
NATURE, NURTURE, AND HUMAN DIVERSITY
Topics:
 Behavior Genetics
 Evolutionary Psychology
 Parents and Peers
 Cultural Influences
 Gender Development
 Why are we so different yet very much the
same?


Nature versus nurture has
been a continuing debate
and is far from being settled.
Whether or not our
characteristics are
determined by the
environmental factors that
surround us or they were
imbedded in our genes is a
question many scientists will
argue.
HISTORY OF THE DEBATE



Traditionally, human nature has been thought
of as not only inherited but divinely ordained.
Whole ethnic groups were considered to be,
by nature, superior or inferior.
In scientific circles, this conflict led to ongoing
controversy of sociobiology and evolutionary
psychology.
Nature vs. Nurture and the Perspectives
PSYCHOANALYTIC
BEHAVIORIST
Innate biological
forces (nature) are
paramount but
early experiences
interact with these
to shape
personality.
Environmental
experiences are
paramount (nurture)
although our
physical make-up
will impose
limitations.
HUMANISTIC
COGNITIVE
Shared biological type
(nature) means that
humans are all
motivated by the same
need to achieve their
potential. Life
(nurture) can help
hinder this.
Nature and nurture
cannot be separated.
The organization and
operation of the brain
and how we process
information are
affected by both.
Perspectives…
BIOLOGICAL
Nature and nurture are
inseparable. They
determine our physical
make-up and interact
to produce behavior.
CHARLES DARWIN



He published his theory with
compelling evidence for evolution in
his 1859 book On the Origin of
Species.
In modified form, Darwin's scientific
discovery is the unifying theory of
the life sciences, explaining the
diversity of life.
Darwin’s theory of evolution, with its
message that traits were inherited,
influenced early psychologists.
Evolutionary Psychology


Evolutionary Psychology explains
psychological traits—such as memory,
perception, or language—as adaptations, that
is, as the functional products of natural
selection or sexual selection.
Modern evolutionary psychologists argue that
much of human behavior is generated by
psychological adaptations that evolved to
solve recurrent problems in human ancestral
environments.
Example:

They hypothesize, for example, that
humans have inherited special mental
capacities for acquiring language,
making it nearly automatic, while
inheriting no capacity specifically for
reading and writing.
Evolutionary Psychology:
Phobias

Phobias are generally caused by an
event recorded by the amygdala and
hippocampus and labeled as deadly or
dangerous; thus whenever a specific
situation is approached again the body
reacts as if the event were happening
repeatedly afterward.
Evolutionary Psychology
How does natural selection work
with regards to behavior?
Survival-oriented behavior is
passed on.
Examples: Fears

Why do people not have phobias of
electricity? It can cause death just
like a poisonous snake.

Sociobiology


Sociobiology is a synthesis of scientific
disciplines which attempts to explain social
behavior in animal species by considering the
Darwinian advantages specific behaviors may
have.
It is often considered a branch of biology and
sociology, but also draws from anthropology,
evolution, zoology, archaeology, population
genetics and other disciplines.
Behavior Genetics



How much are our behavior differences
shaped by our genetic differences? How
much by our environment?
To what extent are we molded by our
upbringing, our culture?
Behavior geneticists study our differences and
weigh the relative effects of heredity and
environment.
GENES


Genes are working subunits of DNA.
DNA is a vast chemical information
database that carries the complete set
of instructions for making all the
proteins a cell will ever need.
Genetic traits: eye color, hair color,
dimples…
Genes vs. the Environment


Some people look at there being two "buckets", genes and
environment, each able to hold a certain capacity of the
trait.
It would be more accurate to represent how the genes
interact with the diagram on the right. It is more of a
blending of environment and heritability.
Hitchhiker’s Thumb
Parents
N offspring
H offspring
Percent N
NxN
281
32
90%
NxH
71
37
66%
HxH
1
30
3%
Curled Tongue
Parents
R offspring
NR offspring
RxR
28
5
R x NR
33
22
NR x NR
4
9
Right Thumb, Left Thumb



Left thumb on top is supposed to indicate a
logical thinker.
Right thumb on top suggests a more creative
mind.
What do you think about this?
Parents
L offspring
R offspring
percent L
LxL
1252
880
59%
LxR
2309
2573
47%
RxR
1298
2815
32%
Vulcan Hand
Earlobes: Free or Attached

Some people have earlobes that curve up between
the lowest point of the earlobe and the point where
the ear joins the head; these are known as "free" or
"unattached" earlobes, as shown in the upper left of
the picture below. Other people have earlobes that
blend in with the side of the head, known as
"attached" or "adherent" earlobes, as shown in the
lower right.
Darwin's Tubercle

Some people have a small bump on the
inside of their upper ear. This is known
as "Darwin's tubercle," because Charles
Darwin mentioned it in his book The
Descent of Man.
Parents
P
offspring
A
offspring
Percent P
PxP
88
59
60%
PxA
101
60
63%
AxA
22
27
45%
Traits


According to search engine trackers, the phrase “are
inherited traits influenced by the environment?” is
one of the most asked science questions online, with
hundreds of hits on Google per day.
On the surface though, it appears a needless
question; of course traits that have a genetic
component are also influenced by the environment.
Behavior Genetics

Attempts to explain individual
differences by using twin studies and
adoption studies.
Behavior Genetics




How much are our behavior differences shaped
by genetic differences?
Behavior Geneticists study our differences and
weigh the relative effects of heredity and
environment.
Human genome researchers have discovered
the common sequence within human DNA. It is
the shared genetic profile that makes us
humans.
Human traits are influenced by gene complexesmany genes acting in concert.
What is Tabula Rasa?

Tabula rasa is the thesis that individuals are born
without built-in mental content and that their
knowledge comes from experience and perception.

Generally proponents of the tabula rasa thesis favor
the "nurture" side of the nature versus nurture
debate, when it comes to aspects of one's
personality, social and emotional behavior, and
intelligence.
Environmental Influence

Five ways we are shaped along with genes:
1.
2.
3.
4.
5.
Prenatal environment
Early experience
Peer Influence
Culture
Gender influences
What is inherited?

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Handedness
Personality
Aggressiveness
Happiness
I.Q.
Gender Identity
Is Handedness Inherited?


There was a time, not too long ago,
when left-handed children felt actively
oppressed--and they were right!
Teachers whacked their hands, other
children teased them, and they were
made to feel that their handedness was
a reflection of flawed character.
Back to the Caveman Days


Man during the stone-age time, used
to kill animals using spears. After
colonies came, man started to fight
against other colonies and also
among themselves.
But as time passed, they noticed that
when they attacked the left part of
the chest (i.e. the heart) the kill was
faster(i.e. the victim would die
faster).
The Shield


Later when he started
advancing in technology, he
started to use a shield for
defense.
But as they knew that the
weak point was on the left of
the chest (heart), the shield
was used with the left hand
and attacking was done using
the right hand
HANDEDNESS



Studying from pre-historic times, right-handedness
prevails in all human cultures. Bias toward the right
hand is unique to humans and primates.
Right-handedness is most common. Right-handed
people are more dexterous with their right hands
when performing a task.
Left-handedness is less common than righthandedness. Left-handed people are more dexterous
with their left hands when performing a task. About
8-15% of people are left-handed.
Mixed Handed/Ambidexterity

Mixed-handedness, also known as cross-

Ambidexterity is exceptionally rare, although it can
dominance, is being able to do different tasks
better with different hands. For example, mixedhanded persons might write better with their right
hand but throw a ball more efficiently with their
left hand.
be learned. A true ambidextrous person is able to
do any task equally well with either hand. Those
who learn it still tend to sway towards their
originally dominant hand.
Left Hand Discrimination


This unfair treatment of lefties was-and still is--a worldwide phenomenon.
In many parts of the world, the left
hand is considered "unclean," and lefthandedness is simply not tolerated; the
word for "left" often has strongly
negative connotations
Lefties Are the Only Ones in
the Right Mind.



90% of the population is right-handed. Of
the 10% who are left-handed, there are more
males than females.
95% of right-handers process information in
their left hemisphere, which tends to be
slightly larger.
Left-handers tend to be more diverse. 50%
process speech in their left hemisphere, as
right-handers do. 25% process language in
the right hemisphere, the other quarter use
both hemispheres.
Lefty Brain Teasers

Because their brains are organized differently, left-handers see and think
differently and can get some very different results from various "brain
tests", usually doing very well on tests that involve creative thinking or
unraveling complex images and manipulating 3D images. Here's a
famous test of creativity - have a look at the image below:
Thurston's hand test

The left-handed brain's mastery of the visual has an important benefit - it
can "see" three dimensionally. In Thurston's hand test, you are asked to
identify which pictures are of left hands and which are of right hands.
Your right-handed brain is at a loss to handle this problem, but your lefthanded brain can actually rotate these drawings in imaginary space to
solve the test - have a go!
Famous Left-Handers

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

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Luke Skywalker
Julius Caesar
Beethoven
Sarah Jessica Parker
Leonardo da Vinci
Tom Cruise
Aristotle
Gandhi
Matthew Broderick
Alexander the Great



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Imagine the centre of your back is itching. Which hand do
you scratch it with?
Interlock your fingers. Which thumb is uppermost?
Imagine you are applauding. Start clapping your hands.
Which hand is uppermost?
Wink at and imaginary friend straight in front of you. Which
eye does the winking?
Put your hands behind your back, one holding the other.
Which hand is doing the holding?
Someone in front of you is shouting but you cannot hear the
words. Cup your ear to hear better. Which ear do you cup?
Count to three on your fingers, using the forefinger of the
other hand. Which forefinger do you use?
Tilt your head to one shoulder. Which shoulder does it touch?
Fixate a small distant object with your eyes and point directly
at it with your forefinger. Now close one eye. Now change
eyes. Which eye was open when the fingertip remained in line
with the small object? (when the other eye, the non-dominant
one, is open and the dominant eye is closed, the finger will
appear to move to one side of the object.)
Fold your arms. Which forearm is uppermost?


The most debated issue pertaining to the
nature theory is the existence of a "gay
gene," pointing to a genetic component to
sexual orientation.
A closer look at the issue of gender helps
to explain the nurture side of the
argument.
What is Gender?



A Gender difference is a distinction of biological
and/or physiological characteristics typically
associated with either males or females of a species
in general.
In the study of humans, socio-political issues arise in
classifying whether a sex difference results from the
biology of gender or our experiences.
Quantitative differences are based on a gradient and
involve different averages. For example, men are
taller than women on average, but an individual
woman may be taller than an individual man.
What is a Schema?



In psychology a schema is an organized
pattern of thought about a certain
subject.
It is a mental structure that we create.
It is a cognitive representation of our
views on a certain subject.
What Schema do you have for
the following:






A
A
A
A
A
A
fireman
ballet dancer
politician
college student
male
female
What is gender identity?
Gender identity is the individual’s subjective
sense of belonging to the male or female
category or indeed neither of the two.
Gender may determine self concept and self
esteem.
Gender may determine the talents that are
cultivated/encouraged (boys vs girls
knowledge & skills).
Biologically sex differences may also
determine traits.
Gender Roles

Gender roles are our expectations about the way
men and women behave.
30 years ago:
 Men were expected to initiate dates, drive the car,
pick up the check.
 Women were expected to decorate the home, raise
the children, and cook and clean.
 Do gender roles reflect what is biologically natural for
men and women or do cultures construct them?
Pink vs. Blue


Gender differences surface early in
children’s play. Boys typically play in
large groups with activity focus and
little intimate discussion. Girls usually
play in smaller groups with one friend.
Girls are less competitive in their play
than boys and initiate social
relationships.
Child Rearing
Gender Identity: our sense of being male or female.
 Gender-typed: some boys exhibit more masculine
traits and some girls exhibit more feminine traits.
Social Learning Theory
 This theory assumes that children learn gender-linked
behaviors by observing and imitating and by being
rewarded or punished.
 “Big boys don’t cry.” Or “You are a good mommy to your
dolls.”

Would you let your son have a
dollhouse?
Would you allow your daughter to
join the wrestling team?
Sex Identity


Sex means biological
maleness/femaleness
Genetic sex denotes
chromosomes (xy & xx)
Sex as Identity


Anatomical sex denotes the physical
sex features
Gender therefore becomes the psychosocial meaning attached to the
biological maleness & femaleness
Gender dysphoria


When sex identity is in conflict with
gender identity (biological vs psychosocial identity)
Sex identity is given & genetic while
gender identity & roles are culturally
constructed.
Gender Dysphoria

Crossdressing

Transsexuality

Gender Identity Disorder (GID)


Hormones & sex reassignment
surgery
Other gender variant issues
Transition
1998
2001
Theories of gender identity
Theory
Gender Schema Theory
Social Learning Theory
Example
Theorist/source
Martin
1991
Bee 1998
Identity Constructed
McManus
Theory
1999
Enculturated-Lens Theory Bem 1999
Social learning theory



Almost from birth children are
treated in gender specific ways
(e.g birth day cards & dress)
Parents & society reinforce
gender specific behaviors &
attitudes.
Boys and girls imitate males &
females respectively
Gender Schema Theory





This theory combines social learning theory with cognition.
Gender becomes a lens through which you view your
experiences.
Age 1- Children discriminate between male and female
voices.
Age 2- Children organize their language according to
gender he/she
Age 3/4- Children seek out their own gender for play.
Age 5/6- Stereotypes about boys/girls peak.
Gender schema theory



Links cognitive development with social learning
theory in the sense that schemas are socialized
cognitive networks of sex & gender roles
People with high gender schemas are more prone to
stereotypic perception & behavior.
High schemas facilitate the creation of cognitive
gender stereotypes & gender values.
Identity constructed theory


This theory emphasises the
individual’s sense of commitment to
a gender category.
The gender category may conflict
with social norms (McManus 1999)
- may lead to gender dysphoria.
Gender and Culture


Most of the research has indicated that sex differences in
expressing emotion tend to be greater in North America
than in other cultures, particularly Asian culture.
Culture impacts gender differences in the expression of
emotions. This may be partly explained by the different
social roles (social role) men and women have in different
cultures, and by the status and power men and women
hold in different societies, as well as the different cultural
values various societies hold
Enculturated-lens theory



Development of gender identity is
embedded in socio-historical context of
each culture.
Culture operates as lens through which
gender identity & gender roles are defined
& passed on as norms of behavior.
Androgyny is the socialized freedom to
identify with male or female roles (Bem
1993).
Bem Sex Role Inventory


The Bem Sex Role Inventory is one of the
most widely used gender measures and
was constructed by the early leading
proponent of androgyny, Sandra Bem
(1977).
Based on their responses to the items in
the Bem Sex-Role Inventory, individuals are
classified as having one of four gender-role
orientations: masculine, feminine,
androgynous, or undifferentiated.
Physical Health



From conception to death, but particularly
before adulthood, females are less vulnerable
than males to developmental difficulties and
chronic illnesses.
This could be due to females having two x
chromosomes instead of just one, or being
unexposed to testosterone.
What other reasons might contribute to this?
Neurology


Female brains are more compact than male brains in
that, though smaller, they are more densely packed
with neurons, particularly in the region responsible
for language.
Also, females have language functions evenly
distributed in both cerebral hemispheres, while in
males they are more concentrated in the left
hemisphere. This puts males more at risk for
language disorders like dyslexia.
Gender and Biology




Biological characteristics may partly explain
gender differences
Hormonal activities tend to influence mind and
body (e.g. aggression & emotionality)
Estrogen (associated with xx) may be a
protective hormone associated with longevity
Estrogen may also be associated with the slow
processing of alcohol & quicker intoxication
Sex and Testosterone

Social psychologist Jim Dabbs &
colleagues found high testosterone
levels in:
 Aggressive boys
 Violent criminals
 Men and women with criminal
records
 Military veterans who went
AWOL or got into trouble after
their service
Testosterone

Strong positive correlation between
testosterone levels and aggression.
 Hormone linked to masculine body
development and behavior in a wide
range of species
 Hens given testosterone act like
roosters, and rise in dominance
hierarchy
The Nature Theory - Heredity
Scientists have known for years that traits such as
eye color and hair color are determined by specific
genes encoded in each human cell.
The Nature Theory takes things a step further to
say that more abstract traits such as intelligence,
personality, aggression, and sexual orientation are
also encoded in an individual's DNA.
I.Q. DEBATE


Evidence suggests that family
environmental factors may have an
effect upon childhood IQ, accounting
for up to a quarter of the variance.
On the other hand, by late adolescence
this correlation disappears, such that
adoptive siblings are no more similar in
IQ than strangers.
Intelligence


Many recent studies have concluded that IQ
performances of men and women vary little. However,
one researcher in the United Kingdom, Richard Lynn, has
authored research showing advantages to men of variable
statistical significance.
Other studies show a greater variance in the IQ
performance of men compared to that of women, i.e.
men are more represented at the extremes of
performance, and less represented at the median.
PERSONALITY

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Personality is a frequently cited example of a heritable
trait that has been studied in twins and adoptions.
Identical twins reared apart are far more similar in
personality than randomly selected pairs of people.
Likewise, identical twins are more similar than fraternal
twins.
Also, biological siblings are more similar in personality
than adoptive siblings.
Each observation suggests that personality is inheritable
to a certain extent. However, these same study designs
allow for the examination of environment as well as
genes.
Big Five Personality Traits

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Openness - appreciation for art, emotion, adventure,
unusual ideas, curiosity, and variety of experience.
Conscientiousness - a tendency to show self-discipline, act
dutifully, and aim for achievement; planned rather than
spontaneous behavior.
Extraversion - energy, positive emotions, urgency, and the
tendency to seek stimulation in the company of others.
Agreeableness - a tendency to be compassionate and
cooperative rather than suspicious and antagonistic towards
others.
Neuroticism - a tendency to experience unpleasant
emotions easily, such as anger, anxiety, depression, or
vulnerability.
Gender and the Big 5


In the big five personality traits, women
score higher in Agreeableness (tendency to
be compassionate and cooperative) and
Neuroticism (tendency to feel anxiety, anger,
and depression).
Demographics of the surveys indicate that
60-75% of women prefer feeling and 5580% of men prefer thinking.
Tannen’s Study




Deborah Tannen’s studies found these gender
differences in communication styles.
The studies also reported that in general both sexes
communicated in similar ways.
Critics, including Suzette Haden Elgin, have
suggested that Tannen's findings may apply more to
women of certain specific cultural and economic
groups than to women in general.
Although it is widely believed that women speak far
more words than men, this is actually not the case.
Parental Influence
PEER INFLUENCE


Children are subject to group influences at all ages.
The conformity behavior of children seeking to fit into certain
groups is a significant influence on day-to-day behavior.
Examples:

Children who refuse to eat certain foods at home will more
likely eat that same food at a table of children who like it.

Children pick up accents and slang from other children.

Children/Teens are influenced by peers who smoke. Parental
has less of an effect than peer influence.
Howard Gardner (1998)- Parents and Peers are
Complimentary
Parents are more important when it comes to:
 -Education
 -Discipline
 -Responsibility
 -Orderliness
 -Charitableness
 -Interaction with Authority Figures
Peers are more important when it comes to:
 -Learning Cooperation
 -Finding Popularity
 -Styles of Interaction with other Peers.
Tannen’s Results
 Men tend to talk more than women in public
situations, but women tend to talk more than men
at home.
 Females are more inclined to face each other and
make eye contact when talking, while males are
more likely to look away from each other.
 Boys tend to jump from topic to topic, but girls tend
to talk at length about one topic.
 When listening, women make more noises such as
“mm-hmm” and “uh-huh”, while men are more likely
to listen silently.
 Women are inclined to express agreement and
support, while men are more inclined to debate.
CULTURAL INFLUENCES



Culture is the behaviors, ideas, attitudes, values,
and traditions shared by a group of people and
transmitted from one generation to another.
Some animals are social such as wolves which live
and hunt in packs. People are social and cultural.
Wolves function the same as they did 10,000 years
ago. People adapt to their environment through
culture.
Cultural differences vary throughout the world. We
live in an extremely multi-cultural society.
VARIATIONS ACROSS CULTURES
Gestures



A gesture is a form of non-verbal communication in which
visible bodily actions are used to communicate particular
messages, either in place of speech or together and in
parallel with spoken words.
Gestures include movement of the hands, face, or other
parts of the body.
Gestures differ from physical non-verbal communication
that does not communicate specific messages, such as
purely expressive displays, proxemics, or displays of joint
attention
TWIN
STUDIES
Identical vs. Fraternal




Identical twins develop from a single fertilized egg that splits
into two and are genetically identical.
They are nature’s own human clones who share the same
conception, uterus, birth date, and usually the same cultural
history.
Fraternal twins are genetically no different than regular
brothers and sisters. There are similarities in the genetic
structure because they related and because of shared
environment.
Are identical twins, being genetic clones of on another,
behaviorally more similar than fraternal twins?
ADOPTION STUDIES



Adoption studies also directly measure the strength
of shared family effects.
Adopted siblings share only family environment.
Unexpectedly, some adoption studies indicate that
by adulthood the personalities of adopted siblings
are no more similar than random pairs of strangers.
This would mean that shared family effects on
personality are zero by adulthood. As is the case
with personality, non-shared environmental effects
are often found to out-weigh shared environmental
effects
Twin Studies

It is unethical to take
a child out of its
natural surroundings
to test nature versus
nurture, so identical
twins have become
the most reliable test
cases for finding the
answers of what is
learned and what is
inherited.
TWIN STUDIES
Fraternal vs. Identical Twins
 Even after they are born, it is sometimes difficult to know
whether twins are identical or fraternal. It can be easier if
they:
 share one placenta (identical)
 are different sexes (fraternal)
 have different blood types (fraternal)
 It is harder to know if they are the same sex, have the
same blood type, or if there are two placentas, since they
could then be either fraternal or identical twins.
Higher Order Multiples





The same factors occur with higher order
multiples, with either multiple eggs being
fertilized or one or more fertilized eggs
splitting.
For example, in the case of triplets, you
could have:
three separate eggs being released and
fertilized by three different sperms (fraternal
triplets)
two separate eggs being released, with one
splitting after it is fertilized (2 of the triplets
will be identical and the other fraternal)
the last type is the most rare, with one egg
being released and splitting three times after
it is fertilized (identical triplets)
Identical Twins vs. Fraternal Twins
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Identical twins develop from a single fertilized egg that
splits into two and are genetically identical.
They are nature’s own human clones who share the same
conception, uterus, birth date, and usually the same cultural
history.
Fraternal twins are genetically no different than regular
brothers and sisters. There are similarities in the genetic
structure because they related and because of shared
environment.
Are identical twins, being genetic clones of on another,
behaviorally more similar than fraternal twins?
Thomas Bouchard 2004
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Bouchard’s study was longitudinal.
*In 1979, Bouchard came across an account of a pair of twins
(Jim Springer and Jim Lewis) who had been separated from
birth and were reunited at age 39.
* "The twins," Bouchard later wrote, "were found to have
married women named Linda, divorced, and married the
second time to women named Betty.
One named his son James Allan, the other named his son
James Alan, and both named their pet dogs Toy."
Twins Reared Apart
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In 1979, Thomas Bouchard began to study twins who
were separated at birth and raised in different families.
He found that an identical twin reared away from his or
her co-twin seems to have about an equal chance of
being similar to the co-twin in terms of personality,
interests, and attitudes as one who has been reared with
his or her co-twin.
This leads to the conclusion that the similarities between
twins are due to genes, not environment, since the
differences between twins reared apart must be due
totally to the environment.
Oskar and Jack
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In one case, identical twin babies (Oskar and Jack)
were raised in extremely different cultures. The two
were born in Trinidad and separated shortly after
birth. After that, their childhoods were very different.
The mother took Oskar back to Germany, where his
grandmother raised him as a Catholic and a Nazi
youth. Jack was raised in the Caribbean as a Jew, by
his father, and spent part of his youth on an Israeli
kibbutz.
Oskar and Jack continued…
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But similarities started cropping up as soon as Oskar
arrived at the airport. Both were wearing wire-rimmed
glasses and mustaches, both sported two-pocket shirts with
epaulets.
They share idiosyncrasies galore: they like spicy foods and
sweet liqueurs, are absentminded, have a habit of falling
asleep in front of the television, think it's funny to sneeze in
a crowd of strangers, flush the toilet before using it, store
rubber bands on their wrists, read magazines from back to
front, dip buttered toast in their coffee...
Bouchard professed himself struck by the similarities in
their mannerisms, the questions they asked, their
"temperament, tempo, the way they do things."
MINNESOTA TWIN FAMILY STUDY
(MTFS)
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MTFS was established in 1989 using same-gendered twin
pairs age 11 or 17.
Twin studies are valuable to researchers because identical
twins share 100% of their genes and fraternal twins share,
on average, 50% of their genes.
Both identical and fraternal twins share certain aspects of
their environment (e.g. religious practices in the home).
This allows researchers to estimate the heritability of
certain traits. Participants are asked about academic ability,
personality, and interests; family and social relationships;
mental and physical health; physiological measurements.
Bouchard
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"Our findings continue to suggest a
very strong genetic influence on
almost all medical and psychological
traits."
SIBLING INTERACTION AND
BEHAVIOR STUDY
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The Sibling Interaction and Behavior Study (SIBS) is a
study of adoptive and biological siblings and their parents.
Because adopted siblings are not biologically related to
each other or their siblings, comparing families in which
two siblings are both adopted, families in which one sibling
is adopted and one is biologically related to the parents,
and families in which both siblings are biologically related
to the parents allows environmental and biological
influence to be teased apart.
Temperament Studies
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Temperament: a person’s characteristic
emotional reactivity and intensity.
Difficult babies are irritable, intense,
and unpredictable.
Easy babies are cheerful, relaxed, and
predictable.
Collectivism
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COLLECTIVISM: Collectivism is defined
as the theory and practice that makes
some sort of group rather than the
individual the fundamental unit of
political, social, and economic concern.
In theory, collectivists insist that the
claims of groups, associations, or the
state must normally supersede the
claims of individuals
Collectivist Society
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Highly collectivistic cultures believe group is most important
unit.
Expect absolute loyalty to group (nuclear family, extended
family, caste, organization)
Group orientation
Decisions based on what is best for the group.
Identity based on social system
Shame culture
Dependence on organization and institutions (Expects
organization / institution / group to take care of individual)
“We” mentality
Emphasis on belonging
Private life “invaded” by institution and organizations to which
one belongs
Individualism
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Individualism is at once an ethical-psychological
concept and an ethical-political one.
As an ethical-psychological concept, individualism
holds that a human being should think and judge
independently, respecting nothing more than the
sovereignty of his or her mind; thus, it is intimately
connected with the concept of autonomy. As an
ethical-political concept, individualism upholds the
supremacy of individual rights
ADOPTION STUDIES
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Adoption studies also directly measure the strength of
shared family effects.
Adopted siblings share only family environment.
Unexpectedly, some adoption studies indicate that by
adulthood the personalities of adopted siblings are no more
similar than random pairs of strangers.
This would mean that shared family effects on personality
are zero by adulthood. As is the case with personality, nonshared environmental effects are often found to out-weigh
shared environmental effects
Individualistic Society
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Highly individualist cultures believe individual is most
important unit
People taking care of themselves (including
immediately family only)
Self-orientation
Identity based on individual
Guilt culture
Making decisions based on individual needs
“I” mentality
Emphasis on individual initiative and achievement
Everyone has a right to a private life
IB Exam Question
Discuss the nature-nurture debate, with reference to
psychological theories and/or studies.
(a) Explain what is meant by the nature-nurture
debate.
(b) Discuss two or more examples of the naturenurture debate in psychology