Human Development Theory

When a psychologist does a very detailed examination of one individual it is called a case study. This is helpful when trying to determine why or how someone is experiencing a stage or aspect of life. Humans are very complicated and individualistic creatures and case studies help to hone in on one individual's uniqueness and solve their specific problems or shed insight on humans the way large scale studies cannot. [4]
During the course of a case study, a psychologist might use naturalistic observation, which is the process of studying people in their normal environment. This can offer much more insight into the way humans think and are affected by society. It can also lead to better data since the subject does not feel awkward or out of place due to a fabricated environment.

Psychoanalytic Theories The most famous psychologist of all time, Sigmund Freud, was the founder of psychoanalysis and psychoanalytic theories. [5] These theories are based on the belief that developmental changes occur because of the influence of internal drives and emotions on behavior.
Freud's Psychosexual Theory
From Freud's psychoanalysis theories psychologists were given one possible insight as to how the conscious and unconscious mind work. [6] Freud believed that there is a constant unconscious drive in humans to seek pleasure, which he called the libido. He argued that the human personality can be divided into three different parts.

1. id

   - Part of the unconscious, the id houses the libido. It is the instinct all humans are born with that gives us carnal, animal like desire. It causes us to pursue sex and be aggressive.

2. ego -

   The ego develops in our first 2 to 3 years of life and is the conscious, thinking part of our minds. The ego is the part of our personalities we are most aware of. Part of the ego's job is to help satisfy the needs of the id. It's job is to keep all three components of personality in harmony.

3. superego -

   The superego is the root of our morality. The rules we are taught by family, friends, and society all merge and become part of the superego. The superego helps us decide between right and wrong. The ego's job is to try and satisfy the id without going against rules set forth by the superego.

When these components are in conflict with one another it creates tension and emotional problems. To get rid of this tension a person might use defense mechanisms which are ways of thinking about a situation to reduce anxiety. Examples of defense mechanisms include repression, denial, or projection. [7] Without defense mechanisms, Freud believed that the person with conflicting personality components would be under so much stress that they develop mental illness or kill themselves.

While Freud was first psychoanalyzing his patients he noticed a trend. Almost all of them had memories of sexual feelings and behaviors from their childhood. As a result, Freud developed a series of stages that he believed everyone went through. These stages all had to do with sexual development. If a child was not given an upbringing which successfully carried them through these stages then they would develop a fixation. They become study at a certain stage, which results in the person acting in ways that show unresolved problems and unmet needs.



The Oedipus complex is a collection of the feelings a young boy has during their phallic stage. According to Freud, boys this age are supposed to have very strong feelings for their mother and because of those feelings they develop a jealousy toward their father. Sometimes the feelings are so strong that they want to kill their father. Girls will have a similar experience called the elektra complex, where their attraction to their father will result in feelings of distaste for their mothers.
Erikson's Psychosocial Stages
Erik Erikson was a psychologist who had an alternative opinion to Freud's about human development. Erikson proposed a theory composed of various stages but rather than focusing on sex he focused on social changes. His theory states that we go through eight stages and that in each one we face a conflict that can either be successfully or unsuccessfully resolved.



The positive characteristics shown in the diagram will only be gained if the dilemma in the stage is successfully resolved. In the case of trust vs. mistrust, the dilemma should be resolved so that the person has trust rather than mistrust.
Freud's psychosexual theory has some shortcomings in that sexual feelings are probably not as important to development as Freud believed. Erikson's psychosocial theory has some shortcomings in that it is very simplified.

Learning Theories Whereas psychoanalytic focus on internal drives and emotions, learning theories propose that through external factors, especially the environment, people can be trained and learn to do or be anything. John Watson, the psychologist who first developed learning theories , called this behavioralism. [1] Behavioralism defines development in terms of behavior changes caused by environment influences. Learning theories say that development should happen through the accumulation experiences.
Pavlov's Classical Conditioning
Ivan Pavlov found that humans can acquire new signals for existing behaviors. This means that we learn through stimuli. We come to expect certain stimulating effects from certain things. He saw that when we know something should happen when we develop a conditioned response. [8]
Skinner's Operant Conditioning
B.F. Skinner proposed operant conditioning, which says that people can learn to repeat or stop behaviors because of the consequences that go along with them. Reinforcement is anything that follows a behavior and causes it to be repeated. This can be as simple as giving out a piece of candy every time the subject has successfully done something. Positive reinforcement would be something pleasant which causes the subject to repeat the behavior over again. It reinforces the action and causes them to do it again in hopes of recieving candy. Punishment is anything that follows a behavior and causes it to stop. Also called negative reinforcement or nonreinforcement, this might involve taking an insulin shot to prevent the negative effects of diabetes. The shot isn't pleasant but most be done to prevent a less pleasant occurence. Extinction occurs when a behavior is completely eliminated through nonreinforcement.
Shaping is the learning of complex behavior through the reinforcement of intermediate steps. An example of this would be learning to play a sport. You learn one step at a time, reinforcing yourself alont the way, until you can finally bring all of the steps together to successfully play the sport.
Bandura's Social-Learning Theory
Albert Bandura was a psychologist who had the idea that learning does not necessarilty require reinforcement. He believed that we can also learn by observing other people. Children learn how to behave by looking at their siblings and other adults. Bandura believes that this kind of learning depends on four things.

1. What the person pays attention to

2. What they are able to remember

3. What they are physicially able to copy

4. What they are motivated to imitate.

Bandura also believed that we learn from not only behavior but also ideas, expectations, internal standards, and self-concepts. Bandura calls this self-efficacy which can influence our well-being and physical health as well as learning. [9]

Cognitive Theories When theories emphasize mental aspects of development such as memory and logic then they are categorized as cognitive theories. These theories look at the human mind as the focal point and base everything around that.
Piaget's Cognitive Developmental Theory
Jean Piaget developed a very famous theory about human development. There are a number of terms that accompaned Piaget's influential theory.

1. scheme

   - An internal cognitive structure that provides an individual with a procedure to use in a specific circumstance.

2. assimilation

   - When we use scemes to make sense of experiences it is called assimilation.

3. accomodation

   - Schemes are sometimes changed as a result of some new information acquired through assimilation.

4. equilibrium -

   The process of balancing assimilation and accomodation to create schemas that fit the environment someone is in.

Piaget divided his theory into stages:


Information-processing Theory - A theoretical model that uses the computer as a model to explain how the mind manages information. Often this model will show how humans receive incoming sensory data which is stored in sensory memory, then sent to short term memory which can then be sent into long-term memory. [10] Since Piaget's theory there has been the development of neo-Piagetian theory . Neo-Piagetian theories often use information-processing principles to explain the development stages in Piaget's theory.

Biological Theories Theories that combine physiological and biological aspects of development are called biological theories. Some can address groups of people and others focus on individuals.There are certain beliefs that biological theories will follow or exhibit, although they are not required.

1. Nativism

   - There is a belief that human beings have genetic traits that will be exhibited in all members of the species. This is called nativism, and is used to explain how people are programmed to be a certain way by their genetic code which the environment has no influence on.

2. Ethology

   - Ethologists believe that survival behaviors evolved through natural selection. Behaviors and skills that are successful will be passed on to the next generation. Those that do not have these necessary skills will die and not pass on their genes. Ethologists also believe that emotional relationships are required for the survival of human infants. For instance, if a mother didn't emotionally respond the the cries of her child then she would have no desire to take care of that child.

3. Sociobiology

   - The study of society using the methods and concepts of biology is called sociobiology. Genes that help groups of people survive are often the core interest of sociobiologists. Sociobiology tries to find the common links in all of human society, or the universal rules that all humans seem biologically programmed to create. Evolution selects the genes that will best promote the survival of the human species .

4. Behavior Genetics

   - Studying how heredity affects individual differences among humans is called behavior genetics. Heredity has been show to affect such things as intelligence, aggressiveness, and shyness. Behavior geneticists have studied identical twins to see what characteristics are present in both because they have the same DNA.

Vgotsky's Sociocultural Theory Piaget believed that complex thinking were developed through a child's explorations. Vgotsky proposed that complex thinking develops through social interactions. [11] When a child's learning experience is guided by an adult it is called scaffolding. For successful scaffolding an adult must model the best strategy, gain and keep the child's attention, and adapt the learning to the child's developmental level, which Vgotsky called the zone of proximal development.

Bronfenbrenner's Ecological Theory Who we are and the actions we make are not defined solely by our inner cognitive mechanism, but are decided in large by exterior environment. Such is the theory presented by scholar Urie Bronfenbrenner in his Ecological Systems Theory. Though Bronfenbrenner has passed away, his work is still widely admired today and was undoubtedly a leader in the field of developmental psychology. His Ecological Systems Theory was first published in 1979. In this theory, Bronfenbrenner presents the concept that there are four environmental systems interlinked bi-directionally that each play a specific role in the development of humans throughout their lifespan. These systems are the microsystem, the exosystem, and the macrosystem. [12]


Diagram Courtesy of http://reginaldwilliams.blogspot.com/2007_04_24_archive.html

Eclecticism A modern trend in human developmental studies is the use of many theories and perspectives to explain and study development. This is called eclecticism and it is helpful because psychologists are no longer restricted to the rigid confines of just one theory anymore. If something isn't accounted for in one theory, then the psychologist can take it from another theory to help with his or her studies. In a sense the theories are molded to represent a more realistic view of human kind.

Theories Compared All of the theories discussed so far have their own merit and usefulness. A developmentalist would look at all of these theories and apply the one which fits their current purposes best. To do this, it is helpful to compare all of the theories at once:

[1]

Conclusion None of these theories are completely correct and none of them are incorrect. They are proposals that shed light on the development of human beings. Psychologists will always argue over which theories are superior to others but the most important thing to keep in mind it doesn't matter. If a theory helps you do your work then it has served its purpose. If you disagree with any of the theories then you can modify them or create your own. Human development is a very interesting and important focus of study and its theories will continue to be useful for anyone interested in the biological and psychological sciences.

References

1. Boyd, D., & Bee, H. (2005). Lifespan Development. Boston: Pearson/A and B.

2. Ridley, M. (2003) Nature Via Nurture: Genes, Experience, and What Makes us Human. Harper Collins.

3. Mental Illness Exacts Heavy Toll, Beginning in Youth. DNA Paternity Testing, Sibling and Immigration Tests.
   http://www.dna-testing-paternity.com/content/7676/mental-illness-exacts-heavy-toll-beginni.php

4. Case Studies. Writing@CSU Home Page
   http://writing.colostate.edu/guides/research/casestudy/

5. The Conscious and Unconscious Mind. About.com.
   http://psychology.about.com/od/theoriesofpersonality/a/consciousuncon.htm

6. FREUD's Theory of Psychosexual Development. a2zpsychology.com
   http://www.a2zpsychology.com/great_psychologists/freud_psychosexual_thoery.htm

7. Section 6: Freud's Ego Defense Mechanisms. AllPsych Online.
   http://allpsych.com/psychology101/defenses.html

8. Classical Conditioning. Ivan Pavlov
   http://www.mucknmire.com/wam101/pavlov.html

9. Social Learning Theory. Ormrod, J.E. (1999). Human learning (3rd ed.). Upper Saddle River, NJ: Prentice-Hall.
   http://teachnet.edb.utexas.edu/~lynda_abbott/Social.html

10. Theories Used in Research Information Processing Theory (2005). Appalachian State University
    http://www.istheory.yorku.ca/informationprocessingtheory.htm

11. Vygotsky & Socio-Cultural Theory. KidsDevelopment
    http://www.kidsdevelopment.co.uk/VygotskySocioCulturalTheory.html

12. Bronfenbrenner, U. (1979). The ecology of human development. Cambridge, MA: Harvard University Press.