Developmental stages, theories of

Encyclopedia of Psychology

"Trust versus mistrust" from birth to 18 months

"Autonomy versus shame" from one-and-a-half; to three years

"Initiative versus guilt" from three to six years

"Industry versus inferiority" from six to 12 years.

"Sensorimotor stage" from birth to two years

"Preoperational stage" from two to seven years

"Concrete operational stage" from seven to 12 years

"Formal operational stage" from 13 to adult.

"Preconventional stage," where moral decisions are based on how they themselves are affected

"Conventional stage," where moral judgments are based on the conventions of society, family, religion, or other social order (Many people do not pass beyond this stage.)

"Post-conventional level," where moral judgments are based on personal beliefs.

Developmental psychologists, by and large, study the way humans develop from an embryo into a full grown adult, focusing mainly on the factors that contribute to intelligence, personality, morality, and lifestyle. Of special interest are the effects certain stimuli have on the development of humans. For instance, does genetics pre-program a person to be introverted, or is that personality trait the result of specific life events that caused him or her to retreat inward? Or, did intense study of music from an early age make someone a gifted musician, or is that something their genes had pre-programmed from the moment of conception?

Over the past hundred years or so, several prominent psychologists and psychiatrists have devised various theories seeking to quantify the developmental stages humans pass through, and in doing so, have sought to map out this difficult process. One of the more famous theories of developmental psychology was put forth by the psychological theorist Erik Erikson in 1963 in his important work Childhood and Society. In this work, Erikson suggests that psychosocial development, the changing ways we perceive ourselves individually and in relation to society, occurs in eight stages-only four of which deal with childhood. The first of Erikson's stages is "trust versus mistrust" and occurs from birth to 1 years. The child formulates either a trusting or mistrusting relationship to the world around it, based on whether its immediate needs are met. These needs, at this young age, generally have to do with satisfaction of physical cravings (food, sleep, and comfort) and for feelings of attachment.

The second stage of development Erikson called "autonomy versus shame" and doubt-occurring between 1 and 3 years of age. Here, young children learn to be independent and autonomous on the condition that they are adequately encouraged to explore their world and given the freedom to do so. On the other hand, children with overly restrictive or anxious parents who wield too great an influence over their children's behavior, stifling creativity and independent exploration of their environment, become shameful and self doubting.

Between the ages of three and six, children pass through the stage Erikson refers to as "initiative versus guilt." During this period of development, children seek to further explore their world by initiating new experiences. The guilt comes about when there are unexpected consequences involved in these initiations. The final stage of childhood development is called "industry versus inferiority," and it lasts from age six to 12. Here, children seek to become industrious in all areas of life, from school to interpersonal relations. Mastery of these skills, with adequate support at home and in school, brings about a sense of overall competence, whereas failure brings about a sense of inferiority.

Another prominent theorist in developmental psychology was Jean Piaget, who developed the four stages of cognitive development. He theorized that people pass from one stage to another not just as a matter of course, but only when they are confronted with the correct type of stimulation to initiate a change. Piaget believed that in the absence of the correct kinds of stimulation, children would never reach their full potential.

According to Piaget, from birth to two years of age, children are in the "sensorimotor" stage of cognitive development. During this stage, children first begin to develop motor skills. They also have little or no ability for what is called symbolic representation, that is, the ability to conceive of things existing outside of their immediate vicinity. Piaget called this ability object permanence. Piaget's next stage is called "preoperational" (from ages two to seven). In this stage, children begin to use language and other representational systems to conceive of, and even discuss, things or people who are not physically present. The chief marker of this stage is what Piaget called egocentric thought. That is, preoperational children can conceive of things that are not present, but they can not conceive of others perceiving what they can not. The classic example of this kind of thinking is the young child who in order to hide simply covers his eyes, thinking that since he can no longer see, no one else can either.