May 1 2012
Make sure to be familiar with the key terms **
**short answer on the exam will be like, define a concept, and give an example
understand and how you can put it in your own words
Issues in Development
What is development? How can we define it?
o Development continues across the life span. Development is change/growth over
the life span
o 1 def: changes that occur over time in though, behavior, reasoning and
functioning of a person due to biological, individual and environmental influences
(whats happening and why its happening ) common elements
Subcategories of Development
1) physical/perceptual development:
o Brain development, changes in perceptual and motor abilities, changes in body
systems and how they function
o Development of thought processes, intellectual abilities, attention, memory,
problem solving, and language. (how much can a five yr old remember relative to
a 12 yr old?)
3)Emotional and Social Development:
o Changes in regulation of emotions, in interpersonal skills, relationship formation,
moral reasoning. (how do temper tantrum changes throughout the decades of
life, how do kids make friends? Who is the most important person in their lifes?
Common breakdown of periods of development
1) Prenatal period : conception to birth
2) Infancy and toddlerhood: birth to 2 years
3) Early childhood: 2 to 6 years
4) Middle childhood: 6 to 11 years
5) Adolescence: 11 to 20 years
Other periods of development
Split adolescence into two components?
o Early adolescence: 11 to 15
o Late adolescence: 16 to 20
When does it end? It doesnt end when you are 20 it keeps going
Need to consider entire lifespan
Age is not development!
Age is a guideline to help us organize how to study and evaluate development
Development is a maturational process independent of age
Age does not cause development
o Experience and genetics cause development
o In developmental psychology, we look at age-related changes Issues in Developmental psychology
1.Nature vs. Nurture
One of the longest running debates in development
Why do we develop individual differences?
Does nature (genetics) or nurture (environment) play a bigger role in our development?
What is the relative contribution of each?
Humans are arguably the only species with language, and language skills typically
emerge around the same age
o indicates a genetic component
Not all humans develop language, and different people develop different languages
o indicates an environmental component
Now most people accept that both factors are involved
Relative influences are still interesting
Watch for this issue throughout the course
o aka: Heredity vs. environment, maturation vs. learning, emergent abilities vs.
Genotype: genetic makeup
o Differences in genotype are due to parental genetic material.
Phenotype: characteristics of individual
o Differences in phenotype are due to differences in genotype and/or differences in
Observable/measurable Heritability:What proportion of individual differences are inherited, from your genes. It doesnt
tell us how the differences develop
Heritability can tell us HOW MUCH variability is explained by genetics, but not HOW
individual differences develop
o Both nature and nurture influence
Extent to which individual differences in phenotypes are due to genetic factors
Question of HOW MUCH
o e.g., measuring intelligence in children & teens: heritability estimate = 0.50 (twin
genetic differences explain about 50% of variation in intelligence in
children and teens
o e.g., measuring correlation of adopted childrens IQ with adoptive vs. biological
Higher with biological parents
Canalization: experience doesnt play much of a role, these are traits that are heavily
controlled by your genes, and no matter what happens to you; you will turn out the same way.
Some traits/characteristics are more influenced by experience, and ones that arent are called
Some behaviours/traits are simply not very responsive to the environment: genetics limit
possible outcomes to only one or a few outcomes
o e.g., infant motor development: sitting, reaching
A strongly canalized characteristic will come out a certain way unless very strong
environmental effects occur
Gene-environment co-variation: genes and environment vary together and how one varies
influences the other, have this cycle of influence, hard to tease apart which is influencing which.
Niche-picking: we tend to do things were naturally good at or enjoy
o Passive or active
Good genes for sports
Enjoys sports, asks to be enrolled in them (active)
Gets lots of practice
o Behaviour influences others
Active: individuals make the choice
Passive: ex; parents who are musicians expose their child to something they enjoy, in this case
they are musicians so they want to expose their child at an early age to music. Still put into a
niche but by the parents decision, not the child.
. Nature vs. Nurture:
Fraternal birth order effect
Do older brothers affect the sexual orientation of younger brothers when the latter are
still in utero (nature)
Does the effect exert itself later, in
childhood or early adolescence? (nurture)
How could we answer this?
boys /male, the more older brother you have the more likely you are to be
homosexual (this only works for right handed males)
Whats causing this effect? Could be a nature thing, having mom carry a whole
bunch of boys changes something in the uterus, something going on in the genetic
early formation of the fetus. (nature) test testosterone level, twins are a good
example. Younger brother who has no biological brothers but a whole bunch of
stepbrothers, and the vice versa..do they show the patern?
A little boy whos growing up with a whole bunch of brothers has certain experiences
that one that grows up with sisters has, learning, something different (nurture). Boy
can idolize older brother and become attracted.
Bogaert (2006) did this and found that boys with older biological brothers were more
likely to be homosexual, but boys raised with older step-brothers were not
Maternal immune response (bogaert) when a women is pregnant.
Theres a conflict between her and the fetus, therefore when the mother is carrying a
boy, there are all these male cells, doesnt have to be all that testosterone, but male
cells/molecules, so the mothers body might see them as foreign bodies and may
elicit anstmmune response.
o 1 child: this happens with first baby, not much is affected
o 2 baby: immune system responds, a little bit better
o 3 and 4 , gets better at fighting off the invasion, this may be causing some