Developmental Psychology

Developmental Psychology

Most of you reading this are anywhere from 16 – 20 years old.  I guarantee that just about ten minutes ago this was going through your mind "what’s on TV tonight- I really need to change my myspace picture- I am really fat….that’s it- NO MORE FOOD- but I am supposed to meet the guys at the Cheesecake factory for buffalo blasts and Godiva cheesecake- oh well, no more eating starting next Monday- that guy in math is so cute- I need some new clothes- school sucks- why can’t I park on campus- school sucks- if my mom asks me one more time to clean my room I am going to scream- school sucks- Lance is gay, no way- school sucks…". 

That is unless you are a 16-20 year old boy, then what was going through your head was more simple "sex- school sucks- sex- hungry-me want chicken wings- sex- school sucks- sex-sex-sex-sex -sex" you get the picture.

I often wonder what is going through my 6 year old son Samuel’s head, "POWER RANGERS SBD GOOOOOOO!!!!!- mommy is so pretty- if I had a superpower, I want to turn into a dinosaur- mommy is so pretty- who would win in a fight, Dora or Batman?- mommy is so pretty".

In my 2 year old Caleb we would have something more like this, "who can I bite now- I want to hurt something- I own everything I see- my Dad is the strongest person ever- give me food of I WILL bite you- what does poo poo taste like- hmmm, not so bad".

In my 6 month old Harris’s head might be, "want milk, want milk, want milk, want touch, want milk, want touch".

In my 30 year old wife’s head, "I love my husband so much- he is da bomb- he is like a combination of Ben Affleck’s looks with Matt Damon’s talent and LL Cool J’s body- I want him- need him- love him- he is my life" (this last thought may be more fantasy, but its my fantasy!!!)

The point behind all of this rambling is that people of different ages have diverse thoughts, needs and wants that are important to them at that time.  None of you are worried about paying the mortgage and your parents are not worried about getting those big puss filled zits (I used to love popping those babies and watching them squirt against the mirror). 

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.  I like to think of Developmental Psychology as the study of humans womb to tomb (cute eh?).

Before we delve into the inner workings of developmental psychology I would like to discuss two things.

First, we will use this unit to try to answer one of the major themes in psychology called the nature vs. nurture argument.  Nature is the idea that your behaviors, thoughts and traits come from our genetics (we are born with them).  Nurture is the idea that our behaviors come from our environment (we learn them from our surroundings).  My best friends Rob and Rob both twirl their hair.  They have both been doing it for years (Rob A had a bald spot in the back of his head, Rob G in the front).  If you were a proponent of nurture, you would say that they both grew up in Rye (sorry, but I did too- go Garnets!!!), had similar stresses, friends and family structure that shaped them into becoming hair twirlers.  You would also think that if raised in a different environment, say the South Bronx, hair twirling might not be their habit of choice.  But if you were a proponent of nature, you would believe that regardless of where the Robs live, they would twirl their hair , because the hair twirling trait is in their genes. 

Most of us like to believe Nurture is the more important factor in our development.  We like to believe that if we try hard enough we can do anything we want to do (a nurture idea).  But Nature does put serious restrictions on our development.  Lets say my father wanted me to play Center for the New York Knicks.  He hires Pat Riley and Mike Krzyzewski (famous basketball coaches) to start training me at 4 years old. 

I train 8 hours a day for 20 years on shooting, dribbling, strategy,  and passing.  Sure I would be better than I am now, but would I ever play center for the Knicks?  Not a chance (unless Isaiah Thomas was making the personnel decisions).  Genetics gave me certain limitations and no matter how much I alter my environment I cannot break through the nature barrier.  Of course, the true answer lies in a combination between the two.

The second issue I want to discuss before we begin is how we study developmental psychology. 

Twins are the best way to study the issue of nature vs. nurture. 

Think about it, if we have a set of identical twins (we will discuss what that is soon- but just know they are two people with almost exactly the same genetic makeup) and one is raised in Harrison by wealthy Jewish parents, the other in Moscow by poor out of work clowns- how similar will the twins be? 

If they are very similar, nature scores points, if not, nurture takes the cake. 

That said, most studies in developmental psychology are either cross-sectional or longitudinal.

  • Cross-Sectional: uses participants of different ages to compare how certain variables may change over the life span.
  • Longitudinal: examines one group of participants over a long period of time

Lets say I wanted to see at what age are people the best at playing Halo (if you do not know what Halo is, you have bigger issues than this course).

  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 five year olds, have them play halo, wait five years and test them again, wait five more years and test them again, them test them again at twenty and I would have my study.  This type of research is much more rare simply because it takes so freaking long!!!!  Both types of research have other advantages and disadvantages that will will discuss in more depth in class.

Lets Get Down to Business

I am going to break developmental psychology down into FOUR sections or types of development.

  1. Physical: the ways our body changes from womb to tomb.
  2. Social: the ways our social needs change from womb to tomb.
  3. Cognitive: the ways our thinking and learning changes from womb to tomb.
  4. Moral: the ways we think about right and wrong changes from womb to tomb.


Physical Development


Physical development pretty much starts the same way for all of us.  Our Dad takes our Mom out for a nice dinner and movie, maybe she has too much to drink, they get back to the house, he puts on some of Marvin Gaye’s  Lets Get it On or anything by Barry White….lets just end that right there. 

What you should probably know about that experience is that you are here because of chromosomes (and Barry White).  Chromosomes are like books that gives instructions for what the body should do.  If chromosomes are the books then the pages that make up the book are called DNA.  To go further- pages are made up of words and in this messed up analogy, the words would be genes and the letters that make up the words would be called nucleotides.  If that whole book analogy made no sense then here it is in plain English – Chromosomes are made up of DNA which are made up of genes which are made of of nucleotides.  Do you have to know what each piece does- no- but know the order and the fact that they are blueprints to who you are.

Lets get back to Mom and Dad and Marvin Gaye (for those of you who have no idea who Marvin Gay or Barry White are- good for you- you are too young- if a guy every starts playing Barry White – run!!!).  Every cell in your parent’s body has 46 chromosomes (23pairs) except for two types of cells- sex cells- your Pop’s sperm and your Mom’s eggs only have 23 chromosomes.  When the sperm rams into the egg they form 46 chromosomes- which was you.  This newly formed you is called a zygote- the first cells of conception (if you really want to know what the music sounded like when you became a zygote click here).


Lets spend a second talking about twins. 

If you were not a twin- then one sperm hit one egg- BAM- one zygote.

Sometimes the woman drops down more than one egg from their ovary and they are both (or even more) fertilized.  When we have two zygotes from two different sperm, they are called Fraternal Twins.  They have just as much in common with each other as you and an older or younger sibling (they just happen to be born at the same time).  So fraternal twins can be of different genders.

The most rare type of conception is when one sperm hits one egg- the zygote is formed, but them splits into two separate zygotes.  Both these two zygotes have pretty much the same genetic material (if one committed a crime DNA evidence could nail the other twin).  These twins are called Identical twins and are the most sought after people in developmental psychology research.

Ok- lets get back to you as a zygote.  As a zygote your cells begin to rapidly divide and your heart begins to beat.  A week or so in you become an embryo.  As an embryo, your organs develop and you become a REALLY small version of yourself.  A couple of months later you become a fetus– and basically you grow bigger and more what you would recognize as human (the lungs are usually the last organ to develop as a fetus).

Things that can go wrong in the womb

Unfortunately, there are many things that can go wrong when a baby is developing in the womb or prenatal environment. You have a placenta that acts as a filter to the fetus, but sometimes dangerous chemicals can travel through the placenta and harm the child.  These agents, whether they are cigarette smoking, drugs or alcohol are called as a group; teratogens.  A teratogen is any chemical agent that can cause harm to the prenatal environment.  The most common teratogen is alcohol and can sometimes cause FAS (Fetal Alcohol Syndrome) characterized by mental retardation and some skull abnormalities.

Another issue that can effect a baby are chromosomal abnormalities.  For example, our gender is determined by the twenty third pair of chromosomes (a man’s sperm carries an X or Y and a woman’s egg has just an X).  If the male gives an X, we have a girl, a Y we have a boy.  Sometimes a baby is born with just a single X chromosome resulting in Turner’s syndrome (shortness, webbed neck and unusual sexual development).  

Babies born with an extra X (XXY) have Klinefelter’s syndrome (minimal sexual development and extreme introversion). 

Other chromosomal abnormalities cause mental retardation like Down’s syndrome (rounded face, shorter fingers, eyes wider apart, low cognitive ability) caused by an extra chromosome on the twenty-first pair.

Wow- now that we talked about all that can go wrong- lets talk about what a healthy baby is like physically.



It used to be that babies were believed to be born as a blank slates- like empty pages just waiting to be written upon (the ultimate nurture perspective).  But we now know that we are born with some basic programming- called reflexes.  The following five reflexes you should know for the AP or just to mess with your baby brother or sister.

  1. Rooting Reflex: when touched on the cheek, the baby will turn their head towards the touch.
  2. Sucking Reflex: the baby will suck on anything put in their mouth.
  3. Grasping Reflex: when something is placed in the palm of hand or foot, the baby will try to grab hold of it.
  4. Moro Reflex: when startled, the baby will flail out its arms and legs, then retract them, making herself as small as possible.
  5. Babinski Reflex: when baby’s foot is stroked, he or she will spread their toes.

Now if your math teacher sticks their finger in your mouth, are you going to begin sucking? 

Probably not, because reflexes go away with brain development.  Also note that these reflexes are different then the ones you have when you touch a burning pot (I will address these types later).

The Newborn’s Development

When healthy babies are born, they also are born with certain preferences for sweet foods (for me that never went away) and are attracted to human voices and humanlike faces as soon as they emerge from the birth canal.  Now babies are born legally blind and can only see 8-12 inches from their face (which is about the distance from the baby to the mother’s face when breast feeding).

A baby’s physical development (ours too) is called maturation.  Maturation is our physical develop that occurs regardless of the environment around you (you cannot really stop growing hair in you armpits no matter where you live or how much education you have).  Essentially the order of our maturation is always the same throughout our lives, but timing varies greatly. 

 What I am trying to say is that we will all learn to sit up before walking, but some of us will walk at 9 months, others at 16 months (12 is the average).  Think about a female’s breast development.  All girls when they hit puberty will begin to develop breasts, but the timing varies.  There is always that one girl that develop breasts about a year before anyone else.  Back at Osborn school in Rye- that girl was named Karen.  We used to snap her bra all the time and really make fun of her.  I still feel kinda bad, but she would make fun of my stutter, so I guess that makes us even.

Physical Development- Adolescence (that period of time in between childhood and adulthood where the zits come out)

The next major changes you body undertakes occurs during puberty (the period of sexual maturation where people become capable of reproducing).  Yep, right now you are going through puberty and your bodies are telling you to go out and make babies (but that would probably be unwise at this juncture because a baby would really get in the way of studying for the AP exam- all those smelly diapers).

I am not going to delve that deeply into puberty (that is what health class and late night cable TV is for), but rather the changes that you are experiencing fall under two major categories.

  1. Primary Sexual Characteristics: the body structures that make sexual reproduction possible- the things you really need (not sexy underwear) but the penis, testicle (only one is necessary), the vagina and the ovaries.
  2. Secondary Sexual Characteristics: nonreproductive sexual characteristics- changes that occur during puberty- but are not necessary for babies (deepening of the make voice, body hair, breasts, widening of the hips).

How do you know when puberty starts? 

Well for a boy the landmark is that first ejaculation.
For a girl it would be the first menstrual period (called the menarche)

How tasteless is this graphic?

Physical Development- Adulthood

After puberty, physical development losing its excitement.  The good news is that your senses (like vision, hearing and smell) tend to peak around the age of 27.  The bad news is that after your 20’s everything begins to deteriorate.  Slowly at first, but around the early 60s, you see a RAPID decline in the senses.  The one major physical milestone in adulthood is menopause, which is when a woman stops releasing eggs, thus stops having their periods.  Men will never experience anything like menopause- we can go on producing sperm until the day we die.

A common problem we see today in aging adults is Alzheimer’s Disease (a progressive and irreversible brain disorder characterized by gradual deterioration of memory, language and physical functioning).  We are not sure of what causes Alzheimer’s Disease but we know it is linked to the deterioration of a natural chemical that our body produces called Acetylcholine (ACH for short).  Acetylcholine is a neurotransmitter that you will learn a lot about when we go over neuroscience (aren’t you just so excited!!!).

Physically, the story always ends the same way- we die. 

Psychiatrist Elizabeth Kubler-Ross said we go through 5 stages before dying (unless you fall into a tree shredder and death happens way to quick to think about.  This is not really physical development, but I could not think of any other place to put it and I might as well write it down while I remember it.

  1. Denial: no freakin way this is happing to me
  2. Anger: How dare god let this happen- this is BS!!!
  3. Bargaining: Just let me live to see my son get married.
  4. Depression: I cannot deal with this, what is my family going to do without me.
  5. Acceptance:  I am ready, I do not want to fight this anymore.

This is Elizabeth Kubler-Ross, she looks way too nice to focus on death.

That is all the reading you have to do for today- if you really want to read ahead than onward to Social Development, lets go!!!!!