Last Page Update: Tue, 05-Feb-2002 3:46 PM

How do psychologists study the degree to which development is a joint function of heredity and enviromental factors?

Developmental psychology is the branch of psychology that studies growth and change throughout life. One fundamental question is how much developmental change is due to nature-- heredity factors-- and how much to nurture-- environmental factors. Most developmental psychologists believe that heredity defines the upper limits of our growth and change, whereas the environment affects the degree to which the upper limits are reached. Cross-sectional research compares people of different ages with one another at some point in time. In contrast, longitudial research traces the behavior of one or more subjects as the subjects become older. Finally, cross-sequential research combines the two methods by taking several different age groups and examining them over several points in time.

What is the nature of development prior to birth, and what factors affect a child during the mother’s pregnancy?

At the moment of conception, the male’s sperm cell and a female’s egg cell unite, with each contributing to the new individual’s genetic make-up. The new cell, a zygote, immediately begins to grow, becoming an embryo measuring about one-fifth of an inch long at four weeks. By the ninth week, the embryo is called a fetus and is responsive to touch and other stimulation. At about twenty eight weeks it reaches the age of viability: It may survive if born prematurely. A fetus is normally born after thirty-eight weeks of pregnancy, weighing around 7 pounds and measuring about 20 inches in length.

What are the major milestone of physical, perceptual and social development after birth?

The newborn, or neonate, has many capabilities. Among them are the rooting reflex, the startle reflex, and the Babinski reflex. After birth, physical development is rapid; children typically triple their birth weights in a year. Perceptual abilities also increase rapidly; infants can distinguish color and depth after just one month. Other sensory capabilities are also impressive ate birth; infants can distinguish sounds and discriminate tastes and smells. However, the development of more sophisticated perceptual abilities depends on increased cognitive abilities. Social development in infancy is marked by the phenomenon of attachment-- the positive emotional bond between a child and a particular individual.

8 Stages

Approximate age

trust vs mistrust stage

Birth - 1 1/2

autonomy vs shame and doubt

1 1/2 - 3

initiative vs guilt stage

3 -6

industry vs inferiority stage

6 -12

identity vs role confusion

Adolescence

intimacy vs. isolation

Early adulthood

generativity vs. stagnation

Middle adulthood

ego-integrity vs despair

Late adulthood

    According to Erikson, eight stages of psychosocial development encompass people’s changing interactions and understanding of themselves and others. During childhood, there are four stages, each of which relates to a crisis that requires resolution. These stages are labeled trust vs mistrust (birth to 18 months), autonomy versus shame and doubt (18 months to 3 years), initiative versus guilt (3 to 6 years) and industry versus inferiority (6 to 12 years).

Stage Age Characteristic
Sensorimotor birth - 2 yrs development of object permanence, development of motor skills , little or no capacity for symbolic representation
Preoperational 2 - 7 years Development of language and symbolic thinking, egocentric thinking
Concrete Operational 7 - 12 years Development of conservation, mastery of concept of reversibility
Formal Operational 12 - onwards Development of logic and abstract thinking

 

Piaget’s theory suggests that cognitive development proceeds through four stages in which qualitative changes occur in thinking. In the sensorimotor stage (birth to 2 years), children develop object permanence, the awareness that objects and people continue to exist even if they are out of sight. In the preoperational stage (2 to 7 years), children display egocentric thought, and by the end of the stage they begin to understand the principle of conservation-- the knowledge that quantity is unrelated to the arrangement and physical appearance of an object. The conservation principle is not fully grasped until the concrete operational stage (7 to 12 years), in which children begin to think more logically, and to understand the concept of reversibility. In the final stage, the formal operational period (12 years to adulthood), thinking becomes abstract, formal and fully logical.

Although Piaget’s theory has had enormous influence, some theorists suggest that the notion of developmental stages is inaccurate. They say that development is more continuous and that the changes occuring within and between changes are reflective of quantitative advances in cognitive development rather than the quality of thought. Because environmental factors play such an important role in cognitive development, child-rearing practices can have an important effect on the degree to which a child realizes his or her genetic potential. Parents can help by giving children the opportunity to explore their environment, being emotionally responsive and involved with their children, being verbally interactive, providing appropriate play materials, giving children a chance to make and learn from mistakes, and holding high expectations.

What major physical, social , and emotional transitions characterize adolescence?

Adolescence, the developmental stage between childhood and adulthood, is marked by the onset of puberty, the point at which sexual maturity occurs. The age at which puberty begins has implications for the way people view themselves and the way they are seen by others. According to Erikson’s model of psychosocial development, adolescence may be accompanied by an identity crisis, although this is by no means universal. Adolescence is followed by three stages of psychosocial development which cover the remainder of the life span.