Transcript ppt: units 3c

AP PSYCHOLOGY
Nature, Nurture, and Human
Diversity
UNIT 3C
How to do define
PSYCHOLOGY?
• The study of
the human
mind AND
human
behavior
Two basic views
• Nativists
Emphasize genes and inborn characteristics
• Empiricists
Emphasize learning and experience
Evolutionary Psychology
• Emphasizes evolutionary mechanisms that
may help explain human commonalities in;
– Cognition, development, emotion, social practices
and other behavior.
In a culture that emphasizes our differences, we
sometimes forget just how similar we are…
HUMAN BEHAVIORAL
GENETICS
• In 1869, FRANCIS
GALTON published the
first empirical work in
human behavioral genetics,
Hereditary Genius.
• Galton intended to
demonstrate that ‘a man's
natural abilities are
derived by inheritance ‘
Behavior
Geneticists
• To what extent does
genetics and environment
influence our behavior?
– Environment means every
external, non-genetic aspect
of our lives, from prenatal
nutrition to the people and
things around us
Pattern Recognition
• Nature v. Nurture
1. Sugar and spice and everything nice, that’s what
little girls are made of…”
2. “Handsome is as handsome does.”
3. “Like father like son.”
4. “You can’t teach an old dog new tricks.”
6. “Boys will be boys.”
7. “You are what you eat.”
8. “Blood will tell.”
9. “All men are created equal.”
SIMILARITIES AS HUMANS
1. Biological
heritage and needs
2. Shared brain
architecture
3. Ability to use language
4. Our senses which we use
to explore
5. Social behaviors
DIFFERENCES AS HUMANS
•
•
•
•
•
•
Personality
Interests
Physical appearance
Family background
Culture
Native-Language
Donald Brown
UNIVERSAL PEOPLE
Donald Brown
Verbal Communications
Donald Brown
Non-verbal Communications
Donald Brown
Rules of Etiquette
Donald Brown
Favoritism for In-Group
Donald Brown
Preference for Kin
Donald Brown
Incest & Children
Donald Brown
Fear Snakes
Donald Brown
Exchange Gifts
Donald Brown
• Demonstrate MODESTY in sexual behavior
and bodily functions
• Labor is divided by age
• Men are more aggressive than women
• Women provide more child care
• Every culture has tools
• People form beliefs about death and disease
• People plan for a future
Donald Brown
•
•
•
•
•
Group identities, but recognize individuality
Cultures have taboos
Societies have sanctions against crimes
People recognize marriage
People flirt, mimic, envy, empathize, joke,
tease and dance and make music
• There are myths and folklore, worldviews and
poetry
•
Genes
The Human Genome Project
• Human Genome
– The genetic blueprint for making a complete
human being
– The sequence of DNA is very similar in people
all over the world.
Kassin, Essentials of Psychology - ©2004 Prentice Hall Publishing
Genes
What Genes Are and How They Work
Genetic Building Blocks
Kassin, Essentials of Psychology - ©2004 Prentice Hall Publishing
Genes
How Genes Affect Behavior
• Genotype
– The underlying DNA sequence that an
individual inherits
• Phenotype
– An organism’s observable properties, physical
and behavioral
• Genes contribute more directly to physical
traits than to psychological characteristics.
Kassin, Essentials of Psychology - ©2004 Prentice Hall Publishing
PUNNETT SQUARE
• The Punnett square is a
diagram designed by
Reginald Punnett and
used by biologists to
determine the probability
of an offspring having a
particular genotype (entire
genetic identity of an
individual)
PUNNETT SQUARE
• Your parents both had two
chromosomes that contain a
gene that you could receive
• We will begin by setting up
a Punnett Square to
determine gender
PUNNETT SQUARE
• You then would label
the chromosomes from
your father (X/Y) on
the side, and the
chromosomes from
your mother (X/X) on
the top like so:
PUNNETT SQUARE
• Next, you match up the
genes on the top with
the ones on the side,
filling all four spaces
of the square like you
see below:
PUNNETT SQUARE
• Two of the spaces have X/Y, and two
others have X/X. Well, since X/Y
means a boy, and X/X means a girl,
you can conclude that two spaces mean
boy and the others mean girl.
• There is a 50% chance of being male,
and a 50% chance of being female.
• This explains why about half the world
is male, and the other half is female.
• This equilibrium can be used on all
traits.
b
EYE COLOR
B
B
b
b
EYE COLOR
B
b
b
B
EYE COLOR
B
b
b
Heterochromia
• It is a result of the relative excess or lack of PIGMENT
within an iris or part of an iris, which may be INHERITED or
acquired by disease or injury. This uncommon condition
usually results due to uneven MELANIN content. A number
of causes are responsible, including genetics such as
CHIMERISM, HORNERS SYNDROME and
WAARDENBURG SYNDROME
Cystic Fibrosis
• A recessive genetic
disorder affecting the
mucus lining of the
lungs, leading to
breathing problems and
other difficulties
PUNNETT SQUARE
• Let us assume, for instance, that both you and your mate are carriers for a
particularly unpleasant genetically inherited disease such as cystic
fibrosis
– A recessive genetic disorder affecting the mucus lining of the lungs, leading to
breathing problems and other difficulties
• You are worried about whether your children will be healthy and
normal.
• For this example, let us define “C" as being the DOMINANT normal
allele and “c" as the RECESSIVE abnormal one that is responsible for
cystic fibrosis.
• As carriers, you and your mate are both heterozygous (Cc).
• This disease only afflicts those who are homozygous recessive (cc).
• The Punnett square makes it clear that at each birth, there will be a 25%
chance of you having a normal homozygous (AA) child, a 50% chance of
a healthy heterozygous (Cc) carrier child like you and your mate, and a
25% chance of a homozygous recessive (cc) child who probably will
eventually die from this condition.
PUNNETT SQUARE
• Some disorders are caused by dominant alleles for
genes.
• Inheriting just one copy of such a dominant allele
will cause the disorder.
– This is the case with Huntington disease, gigantism,
achondroplastic dwarfism, and polydactyly.
• People who are heterozygous (Aa) are not healthy
carriers.
• They have the disorder just like homozygous
dominant (AA) individuals.
Huntington Disease
• Huntington disease (HD) is a disorder
affecting nerve cells in the brain. Mild
symptoms, which include forgetfulness,
clumsiness and personality changes first
appear in middle age.
• Over the next 10-20 years, a person with
HD gradually loses all control of their
mental and physical abilities.
– There is no cure for HD at the moment,
although some of the symptoms can be treated
with drugs.
Genetically Speaking
• Every human is close to being your identical
twin
– 99.9% of your DNA is the same as the other
– 0.01% is what makes the difference!
Twin Biology
Studying the effects of heredity and environment on
two sets of twins, identical and fraternal, has come in
handy.
Fraternal vs. Identical
IDENTICAL
(MONOZYGOTIC) TWINS
• The term twin most
notably refers to two
individuals (or one of
two individuals) who
have shared the same
uterus (womb) and are
usually, but not
necessarily, born on the
same day
• Also called
MONOZYGOTIC
TWINS
FRATERNAL (DIZYGOTIC)
TWINS
• Twins that have been
produced by the
simultaneous fertilization
of two egg cells and who
therefore share only on
average 50 percent of
their genes, just like other
siblings;
• Also called
DIZYGOTIC TWINS
Separated Twins
A number of studies compared identical twins raised
separately from birth, or close thereafter, and found
numerous similarities.
Separated Twins
Personality, Intelligence
Abilities, Attitudes
Interests, Fears
Brain Waves, Heart Rate
Separated Twins
Critics of separated twin studies note that such
similarities can be found between strangers.
Researchers point out that differences between
fraternal twins are greater than identical twins.
Bob Sacha
Adoption Studies
Adoption Studies
Adoption studies, as opposed to twin studies, suggest
that adoptees (who may be biologically unrelated)
tend to be different from their adoptive parents and
siblings.
SEPARATED TWIN STUDY
SEPARATED TWINS
• When given tests
measuring their
personality, intelligence,
heart rate and brain waves
– Identical twins more
similar than Fraternal
twins if separated
– Emphasis on heredity and
environment come into play
to be studied (nature vs.
nurture)
Tamara and Adriana
• Tamara Rabi is a city girl raised Jewish. Adriana
Scott is Catholic and raised in the suburbs. But they
have many similarities in spite of growing up in
different homes.
They're both night people, they both love to dance,
they both want to have a boy and a girl (in that
order) and they both use Pantene shampoo.
Tamara and Adriana
• They're both "B" students, even though Tamara attended a
top private school and Adriana went to public school. And
the subject that gives them both the most trouble? Math.
They look remarkably alike, but they're not exactly alike.
Tamara has a birthmark over her right eyebrow. And Adriana
had braces for five years.
Plus, Tamara says she's a little more outgoing than Adriana,
who admits she's a very shy person.
Tamara and Adriana
• Segal, however, says it's a scientific phenomena that
Adriana and Tamara act alike and even dance the
way they do:
• "All of us are comfortable in certain ways because
of the way our bodies are made.
• And if all of us had identical twins, they'd be sitting
exactly as we are."
Adoptive Studies
Adoptive studies strongly point to the simple fact
that biologically related children turn out to be
different in a family. So investigators ask:
Do siblings have differing experiences?
Do siblings, despite sharing half of their genes, have different
combinations of the other half of their genes?
Ultimate question: Does parenting have an effect?
Parenting
Parenting does have an effect on biologically related
and unrelated children.
Parenting Influences
children’s
Attitudes, Values
Manners, Beliefs
Faith, Politics
Adoption Studies
• Adopted children carry
the genetic inheritance
from their biological
parents into an
environment created by
their adoptive families
ADOPTIVE STUDIES
• Similarities between
the child and the
biological relatives give
clues to the influence of
heredity
ADOPTIVE STUDIES
• Similarities between
the child and the
adoptive parents give
clues to the influence of
environment
ADOPTIVE STUDIES
• Adoptive children tend to
resemble their biological parents
in their personality (their
characteristic pattern of thinking,
feeling, and acting), and their
adoptive parents in their values,
attitudes, manners, faith and
politics)
ADOPTIVE
STUDIES
• Studies of adoptive families have
provided clues to heredity and
environmental influences
• Adopted children share many
values and attitudes with their
adoptive parents, but adopted
children’s personalities tend to
display the genetic legacy of their
biological parents
Is Adoptive Parenting a Fruitless
Venture?
• No.
• The genetic leash may
limit the family
environment’s
influence on
personality, but parents
do influence their
children’s attitudes,
values, manners, faith
and politics
Is Adoptive Parenting a Fruitless
Venture?
• In adoptive homes,
child neglect and abuse
and even parental
divorce are rare
• Except for a somewhat
greater risk of
psychological
disorders; most adopted
children thrive,
especially when
adopted as infants
Temperament Studies
Temperament refers to a person’s stable emotional
reactivity and intensity.
Identical twins express similar temperaments,
suggesting heredity predisposes temperament.
TEMPERMENT
• In psychology,
temperament is the
general nature of an
individual's personality,
such as introversion or
extraversion
TEMPERMENT #1
CHARACTERISTIC
• Temperament, a
person’s
characteristic level of
emotional reactivity
and intensity, is
apparent soon after
birth and tends to
continue relatively
unchanged
TEMPERMENT #2
CHARACTERISTIC
• The second element
common to all
temperament
characteristics is that
these differences are
inherent in the person
TEMPERMENT #3
CHARACTERISTIC
• The third component of
all definitions of
temperament is that
behavioral styles are
relatively stable across
development
How do we Measure
Temperment?
• According to Meyers, most temperament studies
focus on four dimensions: activity, reactivity,
emotionality, and sociability.
- Activity is the intensity and rate of a child's movement and speech.
• How much does the child move around during play or at her desk at school?
– Reactivity is the intensity of a child's approach or withdrawal from
a situation and how long the child is interested in and stays in the
situation.
• How much does a child withdraw from novel toys or new situations?
How do we Measure
Temperment?
– Emotionality is the degree to which a child
expresses negative or positive emotions and how
often she expresses them.
• Does a child get upset easily or become angry quickly?
– Sociability is the tendency to initiate social
contact and the preference to be with others.
• Is the child friendly?
Heritability
Heritability refers to the extent to which the
differences among people are attributable to genes.
HERITABILITY
• Heritability is defined as
the proportion of the total
phenotypic variance in a
trait that is due to the
additive effects of genes, as
opposed to dominance or
environmental effects
HERITABILITY
• Using the twin and
adoption studies and
methods, behavior
geneticists can
mathematically estimate
the heritability of a trait –
the extent to which
variation among individuals
can be attributed to their
differing genes
HERITABILITY
• RULE
– We can never say what
percentage of an
individual’s personality or
intelligence is inherited
• Heritability can vary
from study to study
– Correlation
HERITABILITY
• As environments become more
similar, heredity as a source of
differences necessarily become
more important
• Saying that genes are selfregulating means that genes are
not blueprints, they can react
differently in different
environment
Group Differences
If genetic influences help explain individual diversity
in traits, can the same be said about group
differences?
Group Differences
If genetic influences help explain individual diversity
in traits, can the same be said about group
differences?
Not necessarily.
Group Differences
If genetic influences help explain individual diversity
in traits, can the same be said about group
differences?
Individual differences in weight and height are
heritable and yet nutritional influences have made
westerners heavier and taller than their ancestors
were a century ago.
GROUP DIFFERENCES
• If genetic influences help
explain individual
diversity in traits such as
aggressiveness can the
same be said of group
differences between men
and women, or between
people of different races?
GROUP DIFFERENCES
• Heritable individual
differences need not
imply heritable group
differences
• Aggressive individuals
does not correlate with
aggressive groups
– Putting people in a new
social context can change
their aggressiveness
Genetic Diversity
1
1
Group Differences
If genetic influences help explain individual diversity
in traits, can the same be said about group
differences?
Group Differences
If genetic influences help explain individual diversity
in traits, can the same be said about group
differences?
Not necessarily.
Group Differences
If genetic influences help explain individual diversity
in traits, can the same be said about group
differences?
Individual differences in weight and height are
heritable and yet nutritional influences have made
westerners heavier and taller than their ancestors
were a century ago.
GROUP DIFFERENCES
• Heritable individual
differences need not imply
heritable group differences
• Aggressive individuals does
not correlate with aggressive
groups
– Putting people in a new social
context can change their
aggressiveness
Universal of Bald Men
Gene-Environment Interaction
Genes can influence traits which affect responses, and
environment can affect gene activity.
A genetic predisposition that makes a child
restless and hyperactive evokes an angry response
from his parents.
A stressful environment can trigger genes to
manufacture neurotransmitters leading to
depression.
Gene-Environment Interaction
Genes and environment affect our traits
individually, but more important are their interactive
effects.
Alessia Pierdomenico/Reuters/Corbis
Rex Features
People respond differently to
Rowan Atkinson (Mr. Bean) than Orlando bloom.
OBJECTIVE NINE
• Identify the potential
promise and perils of
molecular genetics
MOLECULAR GENETICS
• Molecular geneticists
study the molecular structure and
function of genes in search of those
that influence behaviors
• Psychologists and molecular
geneticists are working together in
a search to identify specific
genes, or more often, teams of
genes, that put people at risk for
disorders
MOLECULAR GENETICS
• Knowledge of such links
will enable medical
personnel to inform
expectant parents of some
situations in which a fetus
deviates from normal
patterns
– Ethical implications
• Abortion?
• Embryo manipulation
• Stem Cell Research
Nature, Nurture, and Human Diversity
Behavior Genetics: Predicting
Individual Differences
 Genes: Our Codes for Life
 Twin Studies
 Temperament Studies
 Heritability
 Gene-Environment Interaction
 The New Frontier: Molecular Genetics
OBJECTIVE 10
• Describe the area of
psychology that
interests
evolutionary
psychologists
EVOLUTIONARY
PSYCHOLOGY
• Evolutionary psychology is a
theoretical approach to
psychology that attempts to
explain mental and
psychological traits —such as
memory, perception, or
language— as adaptations,
i.e., as the functional products
of natural selection
OBJECTIVE 11
• State the principle of
natural selection, and
point out some possible
effects of natural
selection in the
development of human
characteristics
NATURAL SELECTION
• The concept developed
by Charles Darwin
that genes which
produce characteristics
that are more favorable
in a particular
environment will be
more abundant in the
next generation
Natural Selection
• Charles Darwin (18091882) saw three
problems in need
of a solution.
Problem (the First)
• There is change over time in the
flora and fauna of the Earth
– What we would commonly call
‘evolution’ today
– The fossil record showed this to be
pretty clear, even to people in the
mid 1800s
– This was not controversial in
Darwin’s time, and is not now.
The Second Problem
• There is a taxonomic
relationship among living
things
– People were big into classifying
stuff
– It was pretty obvious that there
was a relationship between
different species
• Different birds, different grasses,
different cats etc
The Third Problem
• Adaptation
– Different kinds of teeth for different animals, say
carnivore ripping teeth and herbivore grinding
teeth
– Different tissues within species
• Heart vs. eye etc.
The Solution!
• Natural Selection provides a mechanistic
account of how these things occurred and
shows how they are intimately related.
• It is one of those ‘oh man is that ever easy,
why didn’t I think of that?’ type things.
How’s it Work?
• Natural Selection determines which
individuals enter the adult breeding
population
– This selection is done by the environment
– Those which are best suited reproduce
– They pass these well suited characteristics on to
their young
This lecture keeps evolving…..
• Survival of the Fittest (which
Charles NEVER said) means
those who have the most
offspring that reproduce
• So, the answer to the trilogy
of problems is:
• ‘Descent with modification
from a common ancestor,
NOT random modification,
but, modification shaped by
natural selection’
Alternate Evolutionary Theories
and Ideas
• Lamarckism
– Inheritance of acquired characteristics
• E.g., giraffes really wanted leaves, so they stretched their necks
and…..
• Sounds crazy, but a lot of people think this way
• ‘We will all have giant heads and tiny bodies someday’
• ‘Cave swelling fish don’t use their eyes so they disappear’
• ‘We don’t use our appendix so it is disappearing’
Alternate Evolutionary Theories and
Ideas
• Orthogenesis
– There is some plan to evolution.
• Mysterious as it is…
– NO WRONG OR INCORRECT, THANKS FOR
PLAYING
– The idea of an ‘evolutionary ladder’ fits in here
– the hypothesis that life has an innate tendency to
move, in a uni-linear fashion, to ever greater
perfection
Alternate Evolutionary
Theories and Ideas
• Intelligent Design
–Creationism
Experience and Brain Development
Early postnatal experiences affect brain
development. Rosenzweig et al. (1984) showed that
rats raised in enriched environments developed
thicker cortices than those in impoverished
environment.
Mating Preferences
Males look for youthful appearing females in order to
pass their genes into the future. Females, on the other,
hand, look for maturity, dominance, affluence and
boldness in males.
Data based on 37 cultures.
Gender Differences in Cognitive
and Personality Traits
• Men outperform women in some visual-spatial skills such
as rotation of three-dimensional objects , throwing accuracy,
and navigation with reference to compass directions;
• Women navigate as well as or better than men with
reference to landmarks, and they have better control of hand
and finger musculature.
Gender Differences in Cognitive
and Personality Traits (cont’d)
• Females outperform males in verbal fluency and
verbal memory skills, whereas males outperform
females in mathematical reasoning and problem solving.
• In personality traits, men score higher than women on
aggressiveness and self-esteem; women score higher
than men on emotional sensitivity and a sense of caring.
Early Care Experiences
• Babies thrive when they
receive warm, responsive
early care
• Early care has a decisive,
long lasting impact on how
people develop, their ability
to learn, and their capacity to
regulate their own emotions
Quality Care for Children
• The way that parents and caregivers relate to
young children and the way they mediate
children’s contact with the environment
directly effects the formation of neural
pathways
Providing Quality Care
• The child care
environment provides an
incredible opportunity to
positively effect child
development
• 7 of 10 children currently
in child care
– 13 million children
• 45% of 1 year-olds,
• 78% of 4 year-olds,
• 84% of 5 year-olds in child
care
• 62% of mothers of
children under 6 work
outside the home
PARENTS’ INFLUENCE
• Freudian psychiatry
and extreme
environmentalism in
early psychology
contributed to the idea
that parents shape their
children’s future
PARENTS’ INFLUENCE
• Influences:
– Manners
– Politics
– Religious beliefs
– Education
– Discipline
– Responsibilities
– Orderliness
– Charitableness
– Interaction with
authority figures
PARENTS’ INFLUENCE
• Non-influences:
– Personality
PEER INFLUENCE
• Children, like adults,
attempt to fit into groups by
conforming
• Children like to seek others
who share their attitudes
and interests
• Interactions
– Cooperation
– Achieving popularity
– Finding style for oneself
Cultural Influences
Humans have the ability to evolve culture. Culture is
composed of behaviors, ideas, attitudes, values and
traditions shared by a group.
Kevin R. Morris/Corbis
Forces Shaping Individual Culture
Urbanization
Nationalism
Colonization
Migration
Minority
Experience
Industrialization
Personal Culture
Social
background
Values
Cross-cultural
Adjustments
Education
World-views
Ethnic
background
Beliefs
Behaviors
Profession
Religion
Gender
Language
• Identify some ways
a primarily
individualist
culture differs from
a primarily
collectivist culture,
and compare their
effects on personal
identity
Culture and Child-Rearing
Individualist cultures (European) raise their children
as independent individuals whereas collectivist
cultures (Asian) raise their children as
interdependent.
Jose Luis Palaez, Inc./ Corbis
Culture and Child-Rearing
Westernized Cultures
Asian-African Cultures
Responsible for your self
Responsible to group
Follow your conscience
Priority to obedience
Discover your gifts
Be true to family-self
Be true to yourself
Be loyal to your group
Be independent
Be interdependent
Gender Roles: Theories
1. Gender Schema Theory suggests that we learn a
cultural “recipe” of how to be a male or a female,
which influences our gender- based perceptions
and behaviors.
2. Social Learning Theory proposes that we learn
gender behavior like any other behavior—
reinforcement, punishment, and observation.
GENDER AND AGGRESSION
• Men more than women
have aggressively and
describe themselves as
aggressive
• The aggression gender
gap appears in many
cultures and at various
stages, especially for
physical aggression
Gender Differences in Aggression
Men express themselves and behave in more
aggressive ways than do women. This aggression
gender gap appears in many cultures and at various
ages.
In males, the nature of this aggression is physical.
In 57 out of 94 studies of aggression; it showed "statistically
significant sex differences" in aggressive behavior.
1.
in 52 of the 57 studies that showed gender differences
in aggressive behavior,boys were more aggressive
than girls.
2. In 5 of the studies, girls were more aggressive than
boys.
3. In 37 studies there were no gender difference in
aggression.
Women and Violence
•
Women commit the majority of child homicides in the U.S.
•
Women commit the majority of physical child abuse in the U.S.
•
Women commit about 25% of the child sexual abuse in the
U.S.
•
Women are primarily responsible for infanticide.
•
30% of the women who killed men in one Chicago study had
previous arrest records for assault, battery, and weapons
charges.
Females are capable of taking up arms . . .
One-third of Columbian rebel
soldiers are female.
. . . and killing people
Violent
Women
Jenny Metcalf
Pearl Hart
Children’s Military Training in China
Afghan Military Parade
Rodeo Champion
Helen Bonham, 1917
Champion Cowgirls
1920
Bonnie McCarroll
Pendleton Roundup, 1915
Annie Oakley, 1890s
Southwestern Cowgirl
1880s
Female Army Scout
1896
GENDER AND SOCIAL POWER
• In most societies, men
are socially dominant
and are perceived as
such
• Men tend to occupy
more leadership
positions, and their
leadership style is more
directive than women’s
Gender and Social Power
In most societies, men are socially dominant and are
perceived as such.
In 2005, men accounted
for 84% of the
governing parliaments.
Women in Politics
We need more women in politics because women are more nurturing
and will transform the political arena.
--Katherine Brown, 1992 Democratic Convention
*
*
*
*
*
However, the following prominent women have not behaved differently
than the men who occupied similar political positions.
•
Margaret Thatcher
•
Gale Norton
•
Indira Gandhi
•
Christie Whitman
•
Golda Meir
•
Phyllis Schlafly
•
Madeleine Albright
•
Condolezza Rice
•
Queen Elizabeth
•
Biljana Plavsic
•
Katherine the Great
Gender Differences and Connectedness
Young and old, women form more connections
(friendships) with people than do men. Men
emphasize freedom and self-reliance.
Dex Image/ Getty Images
Oliver Eltinger/ Zefa/ Corbis
Biology of Sex
Biological sex is determined by the twenty-third pair of
chromosomes. If the pair is XX, a female is produced. If the
pair is XY, a male child is produced.
Sexual Differentiation
In the mother’s womb, the male fetus is exposed to
testosterone (because of the Y chromosome), which leads
to the development of male genitalia.
If low levels of testosterone are released in the uterus,
the result is a female.
Sexual Differentiation
Sexual differentiation is not only biological, but also
psychological and social.
However, genes and hormones play a very important
role in defining gender, especially in altering the brain
and influencing gender differences as a result.
Gender Roles: Theories
1. Gender Schema Theory suggests that we learn a
cultural “recipe” of how to be a male or a female,
which influences our gender- based perceptions
and behaviors.
2. Social Learning Theory proposes that we learn
gender behavior like any other behavior—
reinforcement, punishment, and observation.
Reflections on Nature and Nurture