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Child Development
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Developmental psychology is the study of the physical, cognitive and psychological growth of the individual throughout the life span. Ranges of expected normal development are established and deviations and individual differences observed and studied.

The influence of genetics and environment (nature and nurture) on child development are examined to enhance our understanding and offer insight into possible therapeutic interventions. Although the nature/nurture debate is often heated, it is prudent to remember that most complex behavior is usually the result of a combination of both genetic and environmental influences. The expression of personality or intelligence is the result of many factors and is a mix of inherited (genetic) and acquired (environmental) influences.

Developmental psychologists often describe stages of development. A stage is usually defined by an expected age range and its accompanying identifiable developmental milestones.

Below is a common classification of age ranges.

Age Range

Conception to Birth Prenatal
Birth to 2 years Infant
2 years to 3 years Toddler
3 years to 6 years Early Childhood
6 years to 13 years Middle Childhood
13 years to 20 years Adolescence
20 years to 40 years Young Adulthood
40 years to 65 years Middle Adulthood
65 years and up LateAdulthood

Biological Development

Prenatal development
is characterized by rapid changes. It   is broken down into stages. We commonly hear of the three trimesters that mark the equal division of the nine months of pregnancy. Prenatal development is also usefully divided into the germinal, embryonic and fetal stages.

During the germinal stage, which begins at conception and lasts approximately eight weeks; the zygote (the one celled organism formed by the unification of sperm and ovum) cells divide rapidly. This growing mass of cells travels through the mother's fallopian tube to the uterus. there, it becomes embedded into the uterine lining and the placenta is formed. The placenta surrounds and protects the zygote and brings in nutrients and oxygen while removing wastes.

At approximately two weeks after conception, the zygote has increased in mass and become implanted in the uterus. At this point we begin to speak of it as the embryo. The embryonic stage lasts from approximately week two to week eight. During this period, the embryo continues to grow and most of the body systems and organs begin formation.

The final stage of prenatal development, the fetal stage, lasts from approximately week eight to birth. During the fetal stage growth continues by cell division and the fetus becomes stronger, movement develops and the biological structures become increasingly functional.

Cognitive Development

The growing ability to think, including memory, learning, language and perception is called cognitive development. Children make great strides during their early years as their first impressions interact with their inherited capacities to create concepts and structures to facilitate growing understanding and mastery of their world.

One of the leading theorists of cognitive development was Jean Piaget. He postulated four stages of cognitive development.

Piaget's Stages of Cognitive Development

Stage Age
Sensorimotor Stage Birth to two years
Preoperational Stage Two years to seven years
Concrete Operational Stage Seven years to eleven years
Formal Operational Stage Eleven years and beyond


Psychological Development

Sigmund Freud was one of the most important of all the personality theorists. His theory of child development postulated five "psychosexual stages" in which the child's orientation to the world was based on the biological development of sexual excitation which is focused on different body organs and systems (erogenous zones) as the child develops. The child's activities during these stages are heavily influenced by the gratification of sexual impulses.


Freud's Theory of Psychosexual Development

Age Stage Organ, System, Activity
Birth to 18 months Oral Mouth/sucking, biting
18 months to 3 years Anal Anus/bowel and bladder control
3 years to 6 years Phallic Genitals/self stimulation
6 years to puberty Latency Repression/relative dormancy of sexual excitation
Puberty to adulthood Genital Mature sexual functioning or fixation

Child Development Articles

Planet Psych Links:

Attachment: A New Way of Understanding the Problems of Parents and Kids; Debra Wesselman

Dealing with an Angry Child

Traumatic Events Have Long-Term Impact on Children

Handling Difficult Preschoolers; Jim Windell

Head Banging in Infants; Jim Windell

Self Defeating Behavior; Jim Windell

Parents Can Impact Their Children’s Attitudes Toward Violence





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