Developing Into Humans
Introduction
Development has always been an interesting subject, as that is how we learn why we
are the way we are. As stated by the author of the book, developmental psychology is defined
as, “The study of continuity and change across the life span.” (Schacter, Gilbert, Wegner 308)
There are steps as to how we develop as humans. How we are set to begin our development all
starts in the months between conception and birth in events. You are continuously developing,
the process does not stop. During childhood, children are to learn about how they want to see
the world and what their relationship is to it. This is where they also start to learn what is right
and what is wrong. Then comes adolescent, where they come out of their childhood as they
learn to become independent and “sexual creatures.” (Schacter, Gilbert, Wegner 308) After
adolescent, they start become adults as they are in adulthood. At this stage of their life, “They
typically leave their parents, find mates, have children, and grow old.” (Schacter, Gilbert,
Wegner 308)
Literature Review
Our development starts when we are being conceived, with about 200 million sperms
from our father making a journey into our mother’s vagina, through her uterus, and onto her
fallopian tubes. Only a few make it, as it is a treacherous journey. Some of these sperms that
are making the journey, are defected which makes them unable to swim strongly to get to their
end point. There are some sperms that get stuck in what is called a, “spermatazoidal,” which is
like a traffic jam; they too, never make it to the end. As for the other ones that have made it
past the uterus, they may take a wrong turn and end up in a fallopian tube with no egg.
The sperm has successfully made it and fertilized an egg, the nuclei of the sperm and
egg eventually merge which then the prenatal development stage begins. A zygote as defined
by the book is, “A fertilized egg that contains chromosomes from both a sperm and an egg.”
(Schacter, Gilbert, Wegner 309) The zygote contains all the information, the blueprint for our
development. It contains the genes that will determine what features we will get from our
parents. We are either male or female by what the sperm is carrying, an X chromosome or a Y
chromosome. If you are a male, your father’s sperm carried a Y chromosome; if you are a
female, your father carried an X chromosome. After two weeks of conception, germinal stage
begins. At this stage, cells are being divided. By the time we come out of our mother’s womb,
our cells have divided into a trillion. Zygotes make their way back down to the fallopian tube,
but this is a treacherous journey too, so only half usually make it. The zygote then transplants
itself into the wall of the uterine wall, where the embryonic stage then begins. Cells are divided
and begin to differentiate at this point. There is a little embryo, and it has a heartbeat along
with some other body parts. If it is a little boy, it has even produced testosterone which then
masculinizes their reproductive organs. (Schacter, Gilbert, Wegner 309) The last stage is the
fetal stage, this lasts up until the baby comes out of the mother. It is now a fetus with muscles
and skeleton, with its size growing very fast.
The time has finally come as now the mother has given birth, and she has a newborn
child in her arms. Newborn development is divided into different stages: cognitive, language,
physical, and social. (Infant-Newborn Development) At this point, they have limited range of
vision, but they are very responsive to social stimuli. (Schacter, Gilbert, Wegner 312) Newborn
babies are able to use their eyes right away and have a small set of reflexes, but they are not
able to use other abilities that they have yet. That’s why their development is divided into
different stages. According to the Schacter, Gilbert, Wegner, infants start controlling their
limbs from start to bottom. They start with holding their head up, then eventually learning to
walk. What about what is going on in their minds? “Between infancy and adulthood, children
must come to understand (1) how the physical world works, (2) how their minds represent it,
(3) how other minds represent it. These are the three essential tasks of cognitive
development.” (Schacter, Gilbert, Wegner 312) Cognitive development is divided into four
stages, using their ability to sense and move to gain information from their surroundings.
Between 18 months to 24 months, is when a child starts to develop childhood. It lasts
until adolescence, which then begins between 11 to 14 years of age. According to Medline plus,
“Children grow and mature at very different rates. It’s hard to say what “normal” is. Also,
“Children become more independent from their parents. They may rebel. They also look
outward to their friends, who are usually of the same sex. Peer approval becomes very
important.” (Child Development) This is where they start learning how the world is. I
remember being at this stage, where I started to rebel against my parents because I wanted to
be a “cool kid” too. Being 14 was definitely really tough for me. As stated in the book, “As
children develop into the concreate operational stage, they begin to realize that way the world
appears is not necessarily the way the world is.” (Schacter, Gilbert, Wegner 316) They also start
to discover their minds, as well as other people’s minds. They start to learn that not everyone
may have the same emotional reaction as them. Theory of mind, is what they have acquired
after understanding that everyone is different in perceptions, beliefs, and emotions.
Moral development starts as soon as they are born, but distinctions are not made until
they are older during childhood. They are able to differentiate between pleasure and pain. The
book gives an example as, “But as they mature, they begin to notice that their pleasures
(“Throwing food is fun”) are often someone else’s pains (“Throwing food makes mom mad”)
this is a problem. Human beings need one another to survive and thrive, and when people
make others feel bad, then others tend to avoid them, exclude them, or retaliate against
them.” (Schacter, Gilbert, Wegner 324) They begin to learn what is wrong or right at this point
also. They use rational analyzing to distinguish between two, making moral scenarios making
them think and feel about it.
They now start developing into the adolescent stage. As defined by the book,
“Adolescent is the period of development that begins with the onset of sexual maturity (about
11 to 14 years of age) and lasts until the beginning of adulthood (about 18 to 21 years of age).”
(Schacter, Gilbert, Wegner 328) During the stage, transitions for males and females are very
noticeable. According to the book, “The average adolescent gains about 40 pounds and grows
about 10 inches. Girls’ growth rates begin to accelerate around the age of 10, and they reach
their full heights at around 15 ½ years. Boys experience an equivalent growth spurt about 2
years later and reach their full heights at around 17 ½ years.” (Schacter, Gilbert, Wegner 328)
After reading about this section in the book, I realized why I stopped growing after I was 13
years of age. I definitely had a growth spurt when I was 10, because I was taller than everyone
else in my 4th grade class. It was quite an awkward stage in my life, as I was even taller than all
the boys in my class. My parents definitely thought I was going to end up being 5’11” as I was
so tall already at the age of 10. It did not happen, as I started 8th grade, everyone got taller
while I just stayed the same. I have been 5 feet tall since I was 10! The growth spurts we have
all experienced are signs of puberty. Puberty happening involves primary sex characteristics and
secondary sex characteristics. In girls, breasts are enlarged and hips are widened. What
happens in both genders are facial hair, pubic hair, underarm hair, and lowering of voice.
During puberty, the brain also changes as connections between temporal lobe and parietal lobe
are multiplying rapidly. There is a time when it stops, and that’s when the time for learning a
language ends. The adolescent stage is a more difficult time for boys, as they reach puberty
later, so they mature later. This causes it to be stressful for them, because they are less athletic
and feel not much of a man as others. It is the opposite for girls though, if they go through
puberty earlier, they are the ones who struggle. In the book, it is stated that, “Early-maturing
girls don’t have as much time as their peers do to develop the skills necessary to cope with
adolescence.” (Petersen & Grockett, 1985)
After adolescent, they finally reach adulthood. It is defined in the book as, “the stage of
development that begins around age 18 to 21.” (Schacter, Gilbert, Wegner 334) When we are in
our early 20’s, we are in tip top shape. Our health, stamina, vigor, and prowess are in its prime.
Our cognitive abilities are also at its peak. Years go by, in between 26 and 30, is when you start
slowing down slowly. Your body starts to deteriorate in every way, as stated by the book.
(Schacter, Gilbert, Wegner 334) Everything as this point changes, from the elasticity of your
muscles, to your brain cells dying rapidly. Physically, your body changes too. For women, the
older they get, their ovaries start to stop making eggs and they become infertile.
In conclusion, it takes a lot for us to become who we are. Who would have known that
we started from when we were conceived? I never really thought about it, I figured we only
started developing from when we are developing as a fetus. At each stage of our lives, a lot of
different developments happen. I feel like newborns hit a lot of milestones that parents notice
more often, and not the same goes for when you are in the adolescent stage. The adolescent
stage is a tough time, as we are going through puberty, and we are trying to find ourselves. We
sometimes to begin to distance ourselves from our parents, and so they only see the struggle
we are fighting. I feel like adulthood is when you start finding yourselves, and sometimes things
start becoming easier. I really enjoyed doing this paper, as I learned a lot about how I
developed into the person I am.
Sources:
Child Development: MedlinePlus. (n.d.). Retrieved February 10, 2015.
Introducing Psychology 2nd Edition by Schacter Gilbert Wegner
Mannheim, J. (2013, January 27). Infant - newborn development. Retrieved February 10, 2015.