Chapter 4
Developmental
Psychology
 People of different ages have diverse
thoughts, needs, and wants that are
important to them at that time.
 For example, none of you are worried
about paying the mortgage and your
parents are not worried about getting
clear skin to impress that cute boy/girl
Some psychologists devote their lives to studying the
changes people go through throughout their
lifetime
This branch of psychology is called…
Developmental Psychology
– The study of how our behavior and thoughts change
over time
– Think of it this way …
• the study of humans WOMB
to TOMB
Before we get into developmental psychology we
need to discuss one thing
Chicken or the Egg??
• We will try to answer one of the major themes
in psychology called the Nature vs. Nurture
argument
– Basically asking which is more powerful in
determining behavior and traits??
Nature
– the idea that your behaviors, thoughts and
traits come from our genetics (we are born
with them) (Biology is Destiny)
Nurture
– the idea that our behaviors come from our
environment (we learn from our surroundings)
So which one
is it??
The Nature Argument
(is sometimes compelling)
This guy
will never
be…
Why does Brad Pitt look
the way he does?
Probably genes (and I don’t mean
his Levi's)
This guy!!!
Genes:
Our Biological Blueprint
More on these guys later…
Another way psychologists try to answer Nature vs.
Nurture is through a field called
Evolutionary Psychology
Evolutionary Psychology:
Explaining Universal Behaviors
• According to EP the motivator of all
behavior is the passing of one's genes
to the next generation for survival
– (natural selection and survival of fittest)
Look at our Behaviors…
Can you answer these questions using evolutionary psychology?
• Why do infants fear strangers when they
become mobile?
• Why are most parents devoted to their
children?
• Why do we have more phobias about spiders
and snakes than electricity and nuclear
weapons?
Now, the big one…
How and why do men and
women differ sexually?
• There are of course real biological
differences
Of course, there are other
differences too….
What do men and women want?
(According to Evolutionary Psychology)
• Men want:
• Healthy
• Young
• Waist 1/3 narrower
than hips.
•
•
•
•
Women want:
Wealth
Security
Power
Behavior Genetics
The study of the power and
limitations of genes on who
we are.
The Genetic Revolution
If it were possible, would you want to take
a genetic test telling you which diseases
you are likely to suffer from later in life?
If you or your spouse were pregnant,
would you want the unborn child tested
for genetic defects?
Do you think it should be legal for
employers to use genetic tests in deciding
whom to hire?
Temperament
 The
aspects of a persons personality that we
are born with



whether someone is shy, aggressive, easily scared
They remain relatively stable over time.
Tends to lend evidence that nature is very powerful
What is your temperament??

Heritability
The degree to which genetic factors (heredity) can
explain the differences of a given trait among a
population
 For



example
A heritability estimate of 50% for intelligence
would mean what?
That genetics explains 50% of the differences
among people in IQ scores
The remaining 50% of the differences would be
explained by non-genetic factors, such as
environment influences
Now On to
Nurture
Environmental Influences on
Behavior
Specific Types of
Environmental Influences
Parents
Prenatal
Experience
Peer Influence
Culture
Gender
How Much Credit (or Blame )
Do Parents Deserve?
Are children clay to be molded
by their parents?
 It depends…
 probably not when it comes
to personality
Take a look at your siblings…
are you alike??
Parents effect your
belief systems and values
much more than your personality.
Peer Influence
• Perhaps the biggest
environmental influence, at
least by your age may
be….peers
• “Selection effect”
– we seek out people with similar
interests
– that may explain why we seem to
conform to our peers.
What can happen when there is no
one around to influence children??
Feral Children
• Children who have been
deprived of social contact
or upbringing
– Literally means wild or
untamed
– Suggests the important role
nurture can play in normal
human development
Cultural Influences on Children
• Lev Vygotsky
– Said that one’s thinking
is influenced by one’s
culture
– This interaction produces
a culturally specific way
of thinking
– Zone of Proximal
Development
• Vygotsky thought that if a
child had an older
influence, they would
develop faster
Nature v. Nurture
What do you think so far?
Does Nature and Nurture interact
and grow off of each other?
First, how do psychologists study
this question?
How do Psychologists Study Development??
• Cross sectional
• uses people of different ages to compare how certain
characteristics may change over the course of life
• Can be hard when the groups have grown up in different times
(math tests – computers vs. calculators)
• Longitudinal
• examines one group of participants over a long period of time
• Costly, takes a long time, and typically lose participants over time
• Biographical or retrospective studies
• Looks at one person at a time through individuals memory
• Good for detail, but memory may not be accurate and the
information may not be generalizable
 Lets say I wanted to see at what age


people are the best at playing
Halo
I could go about doing this in two
ways.
If I wanted to do a cross-sectional
study I could take ten 5 year olds,
ten 10 year olds, ten 15 year olds,
and ten 20 year olds, have them all
play Halo and see which group lasted
the longest.
 This would be a fast and easy way to
do the study and MOST studies are
done just like this
• But, if I wanted to do a longitudinal study
I would take ten 5 year olds, have them play
halo, wait five years and test them again,
wait five more years and test them again,
then test them again at twenty and I would
have my study.
• This type of research is much more rare
simply because it takes so long!!!!
• So you can see that both types of research
have advantages and disadvantages.
But lets get down to Business
I am going to break developmental psychology
down into Five sections or types of development
• Physical
– the ways our body changes from womb to tomb
• Social
– the ways our social needs change from womb to tomb
• Cognitive
– the ways our thinking and learning changes from womb
to tomb
• Moral
– the ways we think about right and wrong changes from
womb to tomb
• Gender
– the ways we think about what our gender means from
womb to tomb
Genes: Their Location and
Composition
In the nucleus of every cell we have 46 chromosomes……
Chromosome Breakdown
Chromosomes
Genes
DNA
Nucleotides
Natural Selection at Work
• 1959 Russian Fox story
• 40 Males, 100 Femalesmated- then kept only
tamest of bunch.
• Mated the tames.
• 40 years later
• New Breed of Fox
Cultural Variations
• To understand how cultures effect who we
are it is important to recognize our cultural
norms:
– an understood rule for acceptable behavior.
– The do’s and don’t of a culture
– Because the norms differ from culture to
culture, our behavior also reflects this
– Individual v. Collectivistic Cultures
• How do they impact our behavior??
Variations over Time
• Different generations of the same culture may
also have differing norms and resulting behaviors.
Consider the norms
for dating…