2.4.2 The stages of prenatal development

Lesson Objectives: (Do not answer these questions)

• How delicate is the developing life form at each of the three stages?
• What are the factors that contribute to low birth weight?
• Why are some babies born prematurely?
• What are some common genetic conditions that can be detected during prenatal development?

Research: (ANSWER THESE QUESTIONS)
What are the factors that contribute to low birth weight?
Why are some babies born prematurely?
Define some common genetic conditions that can be detected during prenatal development: club foot, cleft palate/lip, cystic fibrosis, spina bifida, PKU, haemophilia, hydrocephalus, and muscular dystrophy.
What is Fetal Alcohol Syndrome (fetal alcohol spectrum disorder)?
What is Down Syndrome?
Miscarriage: What is it?  What causes it?

2.4.1 Heredity and genetics

Lesson Objectives:

• What are heredity and genetics?
• How are traits passed from one generation to the next?
• What is genetic engineering?
• How do doctors test for genetic disorders?
• What are the ethical and moral issues involved in genetic engineering?
• How can we test the morality of our decisions?

What is heredity and genetics?

Heredity is the process of transmitting biological traits from parent to offspring through genes, the basic units of heredity.  Heredity also refers to the inherited characteristics of an individual including traits such as height, eye colour, and blood type.  Genetics is the study of how heredity works and, in particular, of genes.  A gene is a section of a long deoxyribonucleic acid (DNA) molecule and it carries information for the construction of a protein or part of a protein.  Through the diversity of proteins they code for, genes influence or determine such traits as eye colour, the ability of a bacterium to eat a certain sugar, or the number of peas in a pod.  A virus has as few as a dozen genes.  A simple roundworm has 5 000 to 8 000 genes, while a corn plant has 60 000.  The construction of a human requires an estimated 50 000 genes.  If the DNA in a single human cell could be unraveled, it would form a single thread about 1.5 metres long and about 100 trillionths of a centimetre thick (Lefton et al., 2000, p. 39).

How are traits passed from one generation to the next?

Humans have 23 pairs of chromosomes.  In each pair, one chromosome comes from the mother and the other from the father.  Twenty-two of the pairs are the same in both men and women and these are called autosomes.  The twenty-third pair consists of the sex chromosomes, so called because they are the primary factor in determining the gender of a child.  The sex chromosomes are known as the X and Y chromosomes.  Females have two X chromosomes and males have one X and one Y chromosome.  The Y chromosome is about one-third the size of the X chromosome.  A sperm, the reproductive cell produced by the male, can carry either one X or one Y chromosome.  An egg, the reproductive cell produced by the female, can carry only the X chromosome.  When a sperm with an X chromosome unites with an egg the result is a child with two X chromosomes, a female.  When a sperm with a Y chromosome unites with an egg, however, the result is a child with one X and one Y chromosome, a male.  Thus, the father determines the gender of the child (Baron et al., 1998, p. 74).

What is genetic engineering?

Genetic engineering is the alteration of an organism's genetic instructions through the insertion of additional genes.  In humans genetic engineering involves adding normal genes, either directly via a blood transfusion or bone marrow transplant or directly into a cluster of cells, thereby enabling the body to replace ailing cells with healthy ones.  The technique is being used experimentally for hemophilia, cystic fibrosis, rheumatoid arthritis, several types of cancer, and dozens of rare diseases (Berger, 2000, p. 95).

How do doctors test for genetic disorders?

Scientists have developed a number of tests to determine whether the fetus is developing normally: 

• Amniocentesis is a prenatal medical procedure performed between the 12^th and 16^th weeks of pregnancy in which a sample of amniotic fluid is withdrawn by syringe.  It is tested to discover if the fetus is suffering from any chromosomal or metabolic disorders.
• Ultrasound sonography is a prenatal medical procedure in which high frequency sound waves are directed into the pregnant woman’s abdomen.  The echo from the sounds is transformed into a visual representation of the fetus’s inner structures.
• The chorionic villus test is a prenatal medical procedure in which a small sample of the placenta is removed at some point between the 8^th and the 11^th week of pregnancy.
• The maternal blood test (alpha-fetaprotein test) is a prenatal diagnostic technique that is used to assess neural tube defects.  This test is administered to women 14 to 20 weeks into pregnancy only when they are at risk for bearing a child with defects in the formation of the brain and spinal cord (Santrock, 1999, p. 72).

What are the ethical and moral issues involved in genetic engineering?

Gene mapping and genetic engineering create some dilemmas.  Do people want to know about their genetic defects even though these defects cannot be corrected?  When the issues are genetic screening and abortion, ethical values often clash with practicality and parental rights.  Do parents want to bring to term a child that will have a severe disorder?  One country has already instituted a policy about such disorders.  In 1993, China had a program of abortions, forced sterilization, and marriage bans to avoid new births of “inferior quality” infants and raise the standards of their country.  Worries abound that the information housed in people’s genes will be used to their detriment.  A drop of blood or a lock of hair contains all of the genetic information a potential employer or insurer would need to determine whether someone is at risk of contracting any of a long list of debilitating diseases.  Ethical dilemmas will increase in the next decade as scientists on the Human Genome Project continue to make headway in mapping out human genes (Santrock, 1999, p. 74).

Some experts get nervous about genetic technology for other reasons.  One is genetic screening.  This can be done today for some conditions and it will become more commonplace in the near future.  Careful study of a sample of DNA can reveal how likely a person is to succumb to certain illnesses.  Where the moral dilemma creeps in is whether anybody else should know, and this applies to all genetic screening.  Another concern is the possibility of creating “designer babies.”  Today, when a sperm and an egg unite, chance plays a major role in how the life thus created will turn out.  The embryo will get half its genes from its mother and half from its father.  Whether it inherits its father's tallness or its mother's blue eyes pretty much depends on a roll of the dice.  But genetic engineering holds within it the promise of overcoming the random nature of heredity (Taylor, 2000, p. 7). 

How can we test the morality of our decisions?

In our daily lives, we must make choices that involve questions of honesty, the treatment of other people, acting responsibly, etc.  These are moral choices because they are about right and wrong.  Moral choices are choices between what might be good for us personally and what would be good for others.  We may want to do one thing, but we have doubts about whether we are doing the right thing.  When a situation is morally doubtful we have to have some basis for deciding what to do.  Should an individualistic, personal point of view be taken?  Should one always be “nice” and make sure that everyone else is satisfied?  When should individuals look out for themselves and when should they be concerned about others?

• Ages and Stages : “Cloning: A Twist on Creation”
  • Ian Wilmut, one of the scientists who created Dolly the sheep at the Roslin Institute in Scotland, says the cells from which stem cells are derived are embryonic in nature with no evidence of the formation of a nervous system. In an article in The Globe and Mail in February 2000, he wrote that “the human nervous system will not begin to form until several weeks into a normal pregnancy. In these circumstances, I would consider using the cells of human embryo.” Dr. Wilmut points out that, under British law, a human embryo has special status but not that of a full human being.
    - Discuss his view on using human embryos for research.
    - What does Canadian law say about the issue of fetal rights?
    - What are the legal issues involved in the question of fetal rights?

2.3 Looking through the eyes of the fetus..... What do you see?

What is the process of biological development from conception to birth?

Refer to Lesson 2.1 Unit Overview: Human development from conception to birth, for information regarding the three stages of prenatal development.

What is the process of cognitive development from conception to birth?

Some simple aspects of the functioning of the human nervous system appear very early. Indeed the blood circulation system and the nervous system are the first to function in embryonic life, with heartbeat commencing in the third week following conception. By the second month, an avoidance reaction, the withdrawal of the hand region by contraction of the neck muscles, occurs if an unpleasant stimulus is applied to the embryonic upper lip. These developments imply that simple arc reflexes are already differentiated at this stage, with appropriate synaptic connections and interneuronal activity being brought into play in order to coordinate muscular movements (Rose, 1989, p. 192).

What is the process of socioemotional development from conception to birth?

The fetus is no passive passenger in the womb, nor is the woman simply “carrying” the fetus (Kisilevsky and Low, 1998). Development is interactive even before birth. Research suggests that, at least in some ways, fetuses prepare more than just their reflexes and organ systems for physiological functioning after birth: they also begin to accustom themselves to the particulars of the social world that they soon will join. Meanwhile, mothers begin to identify features of their future offspring: almost all pregnant women, by the last trimester are talking to, patting, and dreaming about their long-awaited child (Berger, 2000, p. 106).

http://www.youtube.com/watch?v=yOB_MqcaZHw

http://www.youtube.com/watch?v=65BV5dXXxzM&NR=1

http://www.babycenter.ca/video/pregnancy/weeks-1-to-9-pregnancy/

2.2 Issues and challenges in becoming a parent

Lesson Objectives:
* What are the issues and challenges in becoming a parent?
* What do you need to know before deciding to have a child?

The National Procreation Council (NPC)

What if prospective parents had to apply to some authority for permission to have children? What if you had to have a license to become a parent? Who should have children? What are the qualities of a good parent? Why do people want and choose to have children? Why do others choose not to have children? These basic questions are the focus of the role play activity.

Prospective parents (Groups of two students).
- Form family units and prepare a case to present to the National Procreation Council. The family units may consist of any combination of people with any type of cultural, religious, socioeconomic, sexual orientation, educational and career background.
- Produce an application and a letter of reference to the NPC. The aim is to indicate:
o The personal qualities you possess that would qualify you to be a good parent
o The situational factors that affect families and the raising of children
o Your reasons for wanting children
o How you intend to raise and care for children.
- Present the application and letter to the NPC to show how worthy you are of children and why your application should be approved.
- Respond to any questions asked by the NPC.

National Procreation Council (five to six students)
- Your job is to develop criteria for evaluating and deciding who shall be approved as parents.
- Produce a set of criteria for evaluating cases and a set of questions to ask prospective parents that will elicit the necessary information for determining each case.

Role play procedure
- Read the What if …? Scenario included in the Curriculum Support Materials, and discuss it with the class. Parent applicants swear an oath to tell the truth as in a judicial procedure and present their case to the NPC. Courtroom-like order is expected to prevail. The NPC hears each case, collects and reads applications, and questions the prospective parents. The NPC then deliberates and evaluates each case. The outcome of each case is presented along with the reasons for the Council's decision. Debrief the activity after the last case is heard.

2.1 Unit Overview: Human development from conception to birth

Lesson Objectives:

* What roles do nature and nurture play in the development of a fetus?
* How do the various domains influence development during the prenatal stage?
* What are the sociocultural influences on prenatal development?

What roles do nature and nurture play in the development of a fetus?

Both genes and environment are necessary for a person to exist. Without genes, there is no person; without environment, there is no person (Scarr and Weinberg, 1980). Heredity and environment operate together, or cooperate, to produce a person’s intelligence, temperament, height, weight, abilities, and so on. The emerging view is that many complex behaviours likely have some genetic loading that gives people a propensity for a particular developmental trajectory. But the actual development requires more - an environment. And that environment is complex, just like the mixture of genes we inherit. Environmental influences range from the things we lump together under “nurture” (such as parenting, family dynamics, schooling, and neighbourhood quality) to biological encounters (such as viruses, birth complications, and even biological events in cells) (Santrock, 1999, p. 83).

How do the various domains influence development during the prenatal development stage?

Physical Development:

* The germinal period is the first two weeks of development. This period is characterized by rapid cell division, the beginning of cell differentiation, and implantation of the blastocyst into the uterine wall. By approximately one week after conception, the zygote is composed of 100 to 150 cells. The differentiation of cells commences and the zygote becomes differentiated into two layers: The blastocyst is the inner layer of cells that later develop into the embryo; the trophoblast is the outer layers of cells that later provides nutrition and support for the embryo. Implantation of the zygote into the uterine wall takes place about 10 days after conception (Santrock, 1999, p. 103).
* The embryonic period is the period of prenatal development that occurs from two to eight weeks after conception. The embryo's endoderm, the inner layer or cells, primarily produces internal body parts such as the respiratory and digestive systems. The middle layer of cells, called the mesoderm, will become the circulatory system, bones, muscle, excretory system, and reproductive system. The outer layer of cells, the ectoderm, will become the nervous system, the sensory receptors (eyes, nose, ears), and skin. As the embryo develops so too does the placenta, the umbilical cord and the amnion (fluid-filled sac) (Santrock, 1999, p. 103).
* The fetal period is the period of development that begins two months after conception and lasts for seven months, on the average. Three months after conception the fetus is 10 centimetres long and weighs approximately 60 grams. It has become active, moving its arms and legs, opening and closing its mouth, and moving its head. The face, forehead, eyelids, nose, and chin are all distinguishable, as are the arms, hands and legs. At four months, a growth spurt occurs in the fetus' lower parts. By the end of the fifth month the toenails and fingernails have formed and the fetus is more active. By the end of the sixth month the eyes and eyelids have completely formed, a grasping reflex is present and irregular breathing occurs. In the last two months, fatty tissues develop and the functioning of various organs such as the heart and kidneys steps up (Santrock, 1999, p. 103).

Cognitive Development:

* Some simple aspects of the functioning of the human nervous system appear very early. Indeed the blood circulation system and the nervous system are the first to function in embryonic life, with heartbeat commencing in the third week following conception. By the second month, an avoidance reaction, the withdrawal of the hand region by contraction of the neck muscles, occurs if an unpleasant stimulus is applied to the embryonic upper lip. These developments imply that simple arc reflexes are already differentiated at this stage, with appropriate synaptic connections and interneuronal activity being brought into play in order to coordinate muscular movements (Rose, 1989, p. 192).

Temperament/Personality Development:

* Every individual is born with a distinct, genetically-based set of psychological tendencies, or dispositions. These tendencies, which together are called temperament, affect and shape virtually every aspect of the individual's developing personality. Temperament, and therefore personality, is not merely genetic: it begins in the multitude of genetic instructions that guide the development of the brain and then is affected by the prenatal environment (Berger, 2000, p. 219).

1.4 Action research in developmental psychology

Lesson Objective:

- How do we use the scientific method to make sense of our behaviour?

Type of Research


Suggested Research Topics

Survey

* Conducting research using a survey involves going out and asking questions about the phenomenon of interest.



* Should the federal government subsidize daycare for all children?
* Should parenting courses for expecting parents be compulsory?
* Should expectant mothers be given fully-paid maternity leave for the term of the pregnancy?
* Should we allow cloning (copying) of human tissue for transplants and surgery?
* Should family size be restricted?
* Should the family allowance be increased to cover all food, educational and health costs for children up to the age of three?
* Should adults wait until they are at least 25 years of age before starting a family?

Interview

* The interview method of research, typically, involves a face-to-face meeting in which a researcher (interviewer) asks an individual a series of questions.



* How have parenting styles changed from when your parents were children?

* What was it like being a teenager when your parents or grandparents were adolescents?

* How has the role of the father in parenting and child-raising changed?

Naturalistic Observation

* In naturalistic research, the observer does not intervene at all. For all intents and purposes, the researcher is invisible and works hard not to interrupt the natural dynamics of the situation being investigated.



* What are the play behaviours of young children?

* Are there gender differences in aggressive behaviour?

* Are there gender differences in the choice, type and use of toys?

* Do mixed gender playgroups change the nature and type of play behaviours?

* Group dynamics: How do groups solve problems?

* What are the various forms and techniques of discipline?

* What effect does violence on television have on people?

Case Study

* A case study is an intensive study of one individual. Typically, the case study is based on interviews with the subject regarding his or her background, present thinking or actions. It may also utilize interviews of others who know the individual. Additional case study material may be obtained through observation, experiments and standardized tests, such as personality inventories and intelligence tests.



* Lives lived. Conduct a case study of a senior or Elder in your family or community and construct a presentation or report on his or her life.

* Who was B.F. Skinner and what role did he play in developmental psychology?

* Who was Ivan Pavlov and what role did he play in developmental psychology?

* Who was Jean Piaget and what role did he play in developmental psychology?

* Who was Albert Bandura and what role did he play in developmental psychology?

* Who was Abraham Maslow and what role did he play in developmental psychology?

* Who was Lev Vygotsky and what role did he play in developmental psychology?



Experimental Research

* Experimental researchers take care to create an environment in which they can make causal statements. They manipulate variables, randomly assign participants to various conditions, and seek to control other influences that could affect their research.



* Eyewitness testimony: How reliable is it? Design a research study to evaluate the accuracy of the recall of observers to an unanticipated event. Stage an unexpected event such as a person bursting into the classroom and describing an “emergency” situation. Once the actor leaves, ask the students to write down exactly what they heard described. Share individual descriptions with the class and discuss the variances in the testimony.

1.3 How do we make sense of our behaviour?

Lesson Objectives:

* How do we make sense of our behaviour?
* What are the methods of research in developmental psychology?
* What are the methodological issues in conducting research?
* What are some of the ethical issues in conducting research?
* How do I conduct research using the scientific method?

How do we make sense of our behaviour?

Science is fundamentally a rational process. In its simplest form, the rational model consists of four steps: (1) formulating a theoretical problem, which is then translated into testable hypotheses; (2) selecting the appropriate research method, and designing and carrying out the study; (3) analyzing and interpreting the results; and (4) using the results to confirm, deny or modify the theory (Alcock, Carment and Sadava, 1998, p. 17).

What are the methods of research in developmental psychology?

Experimental methods came into being because of the need to draw causal inferences about how variables influence one another. Using the experimental method, the researcher deliberately assigns subjects randomly to two or more groups and applies an independent variable to one group and not the other. Then the researcher measures the effect of the treatment by comparing the two groups (Alcock et al., 1998, p. 23).

Interviews typically involve a face-to-face meeting in which a researcher (interviewer) asks an individual a series of questions. The interviewer usually tape records or writes down the participant’s responses (Lefton et al., 2000, p. 14).

Observation involves direct observation of the spontaneous behaviour of an individual, or group of people in a natural setting. The observer may remain aloof and simply observe or become a participant-observer (Baron et al., 1998, p. 20).

A case study is an intensive study of one individual. Typically, the case study is based on interviews with the subject regarding his or her background, present thinking or actions; it may also utilize interviews of others who know the individual. Additional case study material may be obtained through observation, experiments, and standardized tests, such as personality inventories and intelligence tests (Baron et al., 1998, p. 21).

A topical research study involves the acquisition, synthesis, organization and presentation of information. Typically, the topical research study will involve both paper-based as well as web-based resources. Additional information may be gained through the other research methods and strategies.

Survey research involves going out and asking, or sending out, questions about the phenomenon of interest. The survey method is especially useful for collecting data from a large number of people and is often the only way of obtaining data about thoughts, feelings, and private behaviour not open to direct observation (Alcock et al., 1999, p.21).

What are the methodological issues in research?

Reliability is the extent to which the research yields the same results each time they are applied to the same issue. For instance, if we were conducting an observational study of the play behaviours of children during recess, and our findings at the end of one study indicated that the boys were more aggressive than girls, but when we repeated our study at a different school and we found the opposite, that the girls were more aggressive than the boys, then we could not claim that our study was reliable (Baron et al., 1998, p. 459).

Validity is the extent to which a research methodology measures what it is supposed to measure. Continuing with our example of the play behaviours of young children, is the observational approach a valid means of studying the topic? Let’s say that we had chosen to do an interview, and we interviewed the children and asked them questions about what happened at recess time. Would this method be considered valid as a way to gain information from which we could draw a conclusion? Probably not, or not as valid as directly observing them (Baron et al., 1998, p. 459).

What are some of the ethical issues in research?

Confidentiality is the right of privacy for subjects concerning their participation in research. All steps must be taken to assure that subjects’ participation is confidential. If any possibility exists that someone other than the researcher may have access to the data, the subjects must be informed of this possibility before they provide their informed consent to participate (Buskist, Carlson, Enzle and Heth, 1997, p. 42).

Informed consent requires that potential subjects understand exactly what is expected of them during the course of the research and that the investigator protects participants from physical and psychological discomfort, harm, and danger (Buskist et al., 1997, p. 42).

Debriefing requires that research participants be given full information about all aspects of the study after they have participated in it, thus assuring that they leave with a full understanding of its purpose, and receive a full disclosure of the information gathered (Baron et al., 1998, p. 31).

Researchers must be careful to avoid subtle biases that influence results, such as gender (male or female), ethnicity (people’s common traits, background, and allegiances which are often cultural, religious, or language-based), and cultural (a person’s racial and ethnic background, religious and social values, artistic and musical tastes, and scholarly interests) bias (Lefton et al., 2000, p. 15).

How do I make research more valid and reliable?

Scientific investigation includes the possibility that researchers’ procedures and/or biases may compromise the validity of their findings. Researchers can, however, use a number of techniques to increase the validity of their research:

* Sample size: To make statements about people in general, scientists study groups of individuals chosen from populations. Each such group, called a sample, must be large enough to ensure that a few extreme cases within the sample do not distort the picture it gives of the population.


* Representative sample: Data collected from one group of individuals may not be valid for other people who are different in significant ways, such as in gender or ethnic background. Thus it is important that every sample be a representative sample, that is it consists of people who are typical of the general population the researchers wish to learn about.


* “Blind experimenters”: When experimenters have specific expectations about their research findings, those expectations can affect the research results. As much as possible, therefore, the people who actually gather the data should be “blind”, that is, unaware of the purpose of the research.


* Operational definitions: When planning a study, researchers must establish operational definitions of whatever phenomena they will be examining. That is, they must define each variable in terms of specific, observable behaviour that can be measured with precision.


* Experimental and control groups: To test a hypothesis accurately in an experiment, researchers must gather data on two samples that are similar in every important way except one. They must compare an experimental group which receives some special experimental treatment, and a control group, which does not receive the experimental treatment.


* Statistical significance: Whenever researchers find a difference between two groups, they have to consider the possibility that the differences occurred purely by chance. Determining the statistical significance is a mathematical measure of the likelihood that a particular research result occurred by chance (Berger, 2000, pp. 22-23).

1.2 Looking Through the Eyes of... What do you see?

Lesson Objectives:

* What are the four domains of human development?
* What are the theoretical perspectives on human development?


What are the four domains of human development?

Biological processes involve changes in the individual’s physical nature. Genes inherited from parents, the development of the brain, height, weight, changes in motor skills, the hormonal changes of puberty, and cardiovascular decline all reflect the role of biological processes in development (Santrock, 1999, p. 16).

Cognitive processes involve changes in the individual’s thought, intelligence and language. Watching a colourful mobile swinging above the crib, memorizing a poem, imagining what it would be like to be a movie star, and solving a crossword puzzle all reflect the role of cognitive processes in development (Santrock, 1999, p. 16).

Socioemotional processes involve changes in the individual’s relationships with other people, changes in emotions, and changes in personality. An infant’s smile in response to her mother’s touch, a young boy’s aggressive attack on a playmate, a girl’s development of assertiveness, an adolescent’s joy at the senior prom, and the affection of an elderly couple all reflect the role of socioemotional processes in development (Santrock, 1999, p. 17).

By spirituality we mean the experiences that appeal to the human spirit and our connection to God or some spiritual power outside ourselves. Through this spiritual dimension, we try to supply meaning to our lives. We also try to understand the profound sense of awe and mystery at the core of our Beings. It is also our spiritual nature that fuels our drive to express ourselves in painting, music, drama, poetry, architecture, sculpture and other art forms (Badley, 1996, p. 142).

What are the theoretical perspectives on human development?

Lifespan development has produced a number of broad conceptual perspectives representing different approaches to development. Each broad perspective encompasses a number of theories, explanations and predictions concerning phenomena of interest. A theory provides a framework for understanding the relationships among an organized set of principles or facts. The six major theoretical perspectives include:

* Psychodynamic Perspective: Focusing on the inner person. Rooted in Freud’s theory, the psychodynamic approach maintains that all behaviour and mental processes reflect the constant and mostly unconscious psychological struggles that rage silently within each person. Usually, these struggles involve conflict between the impulse to satisfy instincts or wishes and the need to play by the rules in society. Anxiety, depression and other disorders are outward signs of this inner turmoil (Bernstein and Nash, 1999, p. 11).


* The Behavioural Perspective: Considering the outer person. As founded by John Watson, the behavioural approach views behaviour and mental processes as primarily the result of learning. Psychologists who take this approach see rewards and punishment acting on the raw materials provided by genes, evolution and biology to shape each individual. So, whether considering a person’s aggression or drug abuse, behaviourists would look at that person’s learning history. Since people learn problem behaviours, they can also learn to change or even prevent them by unlearning old habits and developing new ones (Bernstein and Nash, 1999, p. 11).


* The Cognitive Perspective: Examining the roots of understanding. The cognitive perspective focuses on how people take in, mentally represent and store information. Cognitive psychologists then relate perception and information processing to patterns of behaviour. They study such areas as decision-making, problem-solving, interpersonal attraction and intelligence. Aggression, for instance, might be viewed as a result of poor problem solving (Bernstein and Nash, 1999, p. 11).

* The Humanistic Perspective: Concentrating on the unique qualities of human beings. According to the humanistic approach, our capacity to choose how to think and act determines our behaviour. Each person’s unique perceptions – not instincts, cognitive processes, or rewards and punishments – dictate the choices made. Humanistic psychologists believe that people are essentially good, that they are in control of themselves, and that they seek to grow toward their highest potential (Bernstein and Nash, 1999, p. 12).


* The Evolutionary Perspective: Focusing on biology as the determinant of development. Darwin’s ideas on evolution and adaptation of species laid the foundation for the evolutionary approach. The evolutionary approach to psychology holds that the behaviour of animals and humans today is the result of evolution through natural selection. Psychologists who follow this approach are concerned with the adaptive value of behaviour, the anatomy and biology that make it possible and the environmental conditions that encourage or discourage it (Bernstein and Nash, 1999, p. 11).


* The Sociocultural Perspective: Emphasizing the systems of support. Calling attention to the external influences on human behaviour such as the physical surroundings and social interactions that provide incentives, opportunities and pathways for growth, Urie Bronfenbrenner (1979) began to emphasize the ecological apporach to the study of human development. In Bronfenbrenner’s application of this concept, human ecosystems include both the physical environment (the climate, the space per person, that arrangement of the dwelling) and the social environment (the people, the culture, the economy) (Berger, 2000, p. 4).