Erikson's stages of psychosocial development
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Erikson's stages of psychosocial development, as articulated by Erik Erikson, in collaboration with Joan Erikson, is a comprehensive psychoanalytic theory that identifies a series of eight stages, in which a healthy developing individual should pass through from infancy to late adulthood. All stages are present at birth but only begin to unfold according to both a natural scheme and one's ecological and cultural upbringing. In each stage, the person confronts, and hopefully masters, new challenges. Each stage builds upon the successful completion of earlier stages. The challenges of stages not successfully completed may be expected to reappear as problems in the future.
However, mastery of a stage is not required to advance to the next stage. The outcome of one stage is not permanent and can be modified by later experiences. Erikson's stage theory characterizes an individual advancing through the eight life stages as a function of negotiating his or her biological forces and sociocultural forces. Each stage is characterized by a psychosocial crisis of these two conflicting forces (as shown in the table below). If an individual does indeed successfully reconcile these forces (favoring the first mentioned attribute in the crisis), he or she emerges from the stage with the corresponding virtue. For example, if an infant enters into the toddler stage (autonomy vs. shame and doubt) with more trust than mistrust, he or she carries the virtue of hope into the remaining life stages.
- 1 Stages
- 1.1 Hope: trust vs. mistrust (oral-sensory, infancy, 0–2 years)
- 1.2 Will: autonomy vs. shame and doubt (early childhood, 2–4 years)
- 1.3 Purpose: initiative vs. guilt (locomotor-genital, preschool, 4–5 years)
- 1.4 Competence: industry vs. inferiority (latency, school age, 5–12 years)
- 1.5 Fidelity: identity vs. role confusion (adolescence, 13–19 years)
- 1.6 Love: intimacy vs. isolation (early adulthood, 20-39 years)
- 1.7 Care: generativity vs. stagnation (adulthood, 40–64 years)
- 1.8 Wisdom: ego integrity vs. despair (maturity, 65 – death)
- 1.9 Ninth stage
- 2 Development of post-Freudian theory
- 3 Critique
- 4 See also
- 5 References
- 6 Publications
0 -18 months
|Hope||Basic trust vs. mistrust||Mother||Can I trust the world?||Feeding, abandonment|
|Will||Autonomy vs. shame and doubt||Parents||Is it okay to be me?||Toilet training, clothing themselves|
|Purpose||Initiative vs. guilt||Family||Is it okay for me to do, move, and act?||Exploring, using tools or making art|
|Competence||Industry vs. inferiority||Neighbors, school||Can I make it in the world of people and things?||School, sports|
|Fidelity||Identity vs. role confusion||Peers, role model||Who am I? Who can I be?||Social relationships|
|Love||Intimacy vs. isolation||Friends, partners||Can I love?||Romantic relationships|
|Care||Generativity vs. stagnation||Household, workmates||Can I make my life count?||Work, parenthood|
|Wisdom||Ego integrity vs. despair||Mankind, my kind||Is it okay to have been me?||Reflection on life|
Hope: trust vs. mistrust (oral-sensory, infancy, 0–2 years)
- Existential Question: Can I Trust the World?
The first stage of Erik Erikson's theory centers around the infant's basic needs being met by the parents and this interaction leading to trust or mistrust. Trust as defined by Erikson is "an essential trustfulness of others as well as a fundamental sense of one's own trustworthiness." The infant depends on the parents, especially the mother, for sustenance and comfort. The child's relative understanding of world and society come from the parents and their interaction with the child. A child's first trust is always with the parent or caregiver; whomever that might be; however, even the caregiver is secondary whereas the parents are primary in the eyes of the child. If the parents expose the child to warmth, regularity, and dependable affection, the infant's view of the world will be one of trust. Should the parents fail to provide a secure environment and to meet the child's basic needs; a sense of mistrust will result. Development of mistrust can lead to feelings of frustration, suspicion, withdrawal, and a lack of confidence.
According to Erik Erikson, the major developmental task in infancy is to learn whether or not other people, especially primary caregivers, regularly satisfy basic needs. If caregivers are consistent sources of food, comfort, and affection, an infant learns trust—that others are dependable and reliable. If they are neglectful, or perhaps even abusive, the infant instead learns mistrust—that the world is an undependable, unpredictable, and possibly a dangerous place. While negative, having some experience with mistrust allows the infant to gain an understanding of what constitutes dangerous situations later in life; yet being at the stage of infant or toddler, it is a good idea not to put them in situations of mistrust: the child's number one needs are to feel safe, comforted, and well cared for.
Will: autonomy vs. shame and doubt (early childhood, 2–4 years)
- Existential Question: Is It Okay to Be Me?
As the child gains control over eliminative functions and motor abilities, they begin to explore their surroundings. The parents still provide a strong base of security from which the child can venture out to assert their will. The parents' patience and encouragement helps foster autonomy in the child. Children at this age like to explore the world around them and they are constantly learning about their environment. Caution must be taken at this age while children may explore things that are dangerous to their health and safety.
At this age children develop their first interests. For example, a child who enjoys music may like to play with the radio. Children who enjoy the outdoors may be interested in animals and plants. Highly restrictive parents, however, are more likely to instill in the child a sense of doubt, and reluctance to attempt new challenges. As they gain increased muscular coordination and mobility, toddlers become capable of satisfying some of their own needs. They begin to feed themselves, wash and dress themselves, and use the bathroom.
If caregivers encourage self-sufficient behavior, toddlers develop a sense of autonomy—a sense of being able to handle many problems on their own. But if caregivers demand too much too soon, refuse to let children perform tasks of which they are capable, or ridicule early attempts at self-sufficiency, children may instead develop shame and doubt about their ability to handle problems.
Purpose: initiative vs. guilt (locomotor-genital, preschool, 4–5 years)
- Existential Question: Is it Okay for Me to Do, Move, and Act?
Initiative adds to autonomy the quality of undertaking, planning and attacking a task for the sake of just being active and on the move. The child is learning to master the world around them, learning basic skills and principles of physics. Things fall down, not up. Round things roll. They learn how to zip and tie, count and speak with ease. At this stage, the child wants to begin and complete their own actions for a purpose. Guilt is a confusing new emotion. They may feel guilty over things that logically should not cause guilt. They may feel guilt when this initiative does not produce desired results.
The development of courage and independence are what set preschoolers, ages three to six years of age, apart from other age groups. Young children in this category face the challenge of initiative versus guilt. As described in Bee and Boyd (2004), the child during this stage faces the complexities of planning and developing a sense of judgment. During this stage, the child learns to take initiative and prepare for leadership and goal achievement roles. Activities sought out by a child in this stage may include risk-taking behaviors, such as crossing a street alone or riding a bike without a helmet; both these examples involve self-limits.
Within instances requiring initiative, the child may also develop negative behaviors. These behaviors are a result of the child developing a sense of frustration for not being able to achieve a goal as planned and may engage in behaviors that seem aggressive, ruthless, and overly assertive to parents. Aggressive behaviors, such as throwing objects, hitting, or yelling, are examples of observable behaviors during this stage.
Preschoolers are increasingly able to accomplish tasks on their own, and can start new things. With this growing independence comes many choices about activities to be pursued. Sometimes children take on projects they can readily accomplish, but at other times they undertake projects that are beyond their capabilities or that interfere with other people's plans and activities. If parents and preschool teachers encourage and support children's efforts, while also helping them make realistic and appropriate choices, children develop initiative—independence in planning and undertaking activities. But if, instead, adults discourage the pursuit of independent activities or dismiss them as silly and bothersome, children develop guilt about their needs and desires.
Competence: industry vs. inferiority (latency, school age, 5–12 years)
- Existential Question: Can I Make it in the World of People and Things?
The aim to bring a productive situation to completion gradually supersedes the whims and wishes of play. The fundamentals of technology are developed. The failure to master trust, autonomy, and industrious skills may cause the child to doubt his or her future, leading to shame, guilt, and the experience of defeat and inferiority.
The child must deal with demands to learn new skills or risk a sense of inferiority, failure, and incompetence.
"Children at this age are becoming more aware of themselves as individuals." They work hard at "being responsible, being good and doing it right." They are now more reasonable to share and cooperate. Allen and Marotz (2003) also list some perceptual cognitive developmental traits specific for this age group. Children grasp the concepts of space and time in more logical, practical ways. They gain a better understanding of cause and effect, and of calendar time. At this stage, children are eager to learn and accomplish more complex skills: reading, writing, telling time. They also get to form moral values, recognize cultural and individual differences and are able to manage most of their personal needs and grooming with minimal assistance. At this stage, children might express their independence by talking back and being disobedient and rebellious.
Erikson viewed the elementary school years as critical for the development of self-confidence. Ideally, elementary school provides many opportunities to achieve the recognition of teachers, parents and peers by producing things—drawing pictures, solving addition problems, writing sentences, and so on. If children are encouraged to make and do things and are then praised for their accomplishments, they begin to demonstrate industry by being diligent, persevering at tasks until completed, and putting work before pleasure. If children are instead ridiculed or punished for their efforts or if they find they are incapable of meeting their teachers' and parents' expectations, they develop feelings of inferiority about their capabilities.
At this age, children start recognizing their special talents and continue to discover interests as their education improves. They may begin to choose to do more activities to pursue that interest, such as joining a sport if they know they have athletic ability, or joining the band if they are good at music. If not allowed to discover their own talents in their own time, they will develop a sense of lack of motivation, low self-esteem, and lethargy. They may become "couch potatoes" if they are not allowed to develop interests.
Fidelity: identity vs. role confusion (adolescence, 13–19 years)
- Existential Question: Who Am I and What Can I Be?
The adolescent is newly concerned with how they appear to others. Superego identity is the accrued confidence that the outer sameness and continuity prepared in the future are matched by the sameness and continuity of one's meaning for oneself, as evidenced in the promise of a career. The ability to settle on a school or occupational identity is pleasant. In later stages of adolescence, the child develops a sense of sexual identity. As they make the transition from childhood to adulthood, adolescents ponder the roles they will play in the adult world. Initially, they are apt to experience some role confusion—mixed ideas and feelings about the specific ways in which they will fit into society—and may experiment with a variety of behaviors and activities (e.g. tinkering with cars, baby-sitting for neighbors, affiliating with certain political or religious groups). Eventually, Erikson proposed, most adolescents achieve a sense of identity regarding who they are and where their lives are headed.
The teenager must achieve identity in occupation, gender roles, politics, and, in some cultures, religion.
Erikson is credited with coining the term "identity crisis".:39 Each stage that came before and that follows has its own 'crisis', but even more so now, for this marks the transition from childhood to adulthood. This passage is necessary because "Throughout infancy and childhood, a person forms many identifications. But the need for identity in youth is not met by these." This turning point in human development seems to be the reconciliation between 'the person one has come to be' and 'the person society expects one to become'. This emerging sense of self will be established by 'forging' past experiences with anticipations of the future. In relation to the eight life stages as a whole, the fifth stage corresponds to the crossroads:
What is unique about the stage of Identity is that it is a special sort of synthesis of earlier stages and a special sort of anticipation of later ones. Youth has a certain unique quality in a person's life; it is a bridge between childhood and adulthood. Youth is a time of radical change—the great body changes accompanying puberty, the ability of the mind to search one's own intentions and the intentions of others, the suddenly sharpened awareness of the roles society has offered for later life.
Adolescents "are confronted by the need to re-establish [boundaries] for themselves and to do this in the face of an often potentially hostile world". This is often challenging since commitments are being asked for before particular identity roles have formed. At this point, one is in a state of 'identity confusion', but society normally makes allowances for youth to "find themselves", and this state is called 'the moratorium':
The problem of adolescence is one of role confusion—a reluctance to commit which may haunt a person into his mature years. Given the right conditions—and Erikson believes these are essentially having enough space and time, a psychosocial moratorium, when a person can freely experiment and explore—what may emerge is a firm sense of identity, an emotional and deep awareness of who he or she is.
As in other stages, bio-psycho-social forces are at work. No matter how one has been raised, one's personal ideologies are now chosen for oneself. Often, this leads to conflict with adults over religious and political orientations. Another area where teenagers are deciding for themselves is their career choice, and often parents want to have a decisive say in that role. If society is too insistent, the teenager will acquiesce to external wishes, effectively forcing him or her to ‘foreclose' on experimentation and, therefore, true self-discovery. Once someone settles on a worldview and vocation, will he or she be able to integrate this aspect of self-definition into a diverse society? According to Erikson, when an adolescent has balanced both perspectives of "What have I got?" and "What am I going to do with it?" he or she has established their identity:
Dependent on this stage is the ego quality of fidelity—the ability to sustain loyalties freely pledged in spite of the inevitable contradictions and confusions of value systems. (Italics in original)
Given that the next stage (Intimacy) is often characterized by marriage, many are tempted to cap off the fifth stage at 20 years of age. However, these age ranges are actually quite fluid, especially for the achievement of identity, since it may take many years to become grounded, to identify the object of one's fidelity, to feel that one has "come of age". In the biographies Young Man Luther and Gandhi's Truth, Erikson determined that their crises ended at ages 25 and 30, respectively:
Erikson does note that the time of Identity crisis for persons of genius is frequently prolonged. He further notes that in our industrial society, identity formation tends to be long, because it takes us so long to gain the skills needed for adulthood's tasks in our technological world. So… we do not have an exact time span in which to find ourselves. It doesn't happen automatically at eighteen or at twenty-one. A very approximate rule of thumb for our society would put the end somewhere in one's twenties.
Love: intimacy vs. isolation (early adulthood, 20-39 years)
- Existential Question: Can I Love?
The Intimacy vs. Isolation conflict is emphasized around the age of 30. At the start of this stage, identity vs. role confusion is coming to an end, though it still lingers at the foundation of the stage (Erikson, 1950). Young adults are still eager to blend their identities with friends. They want to fit in. Erikson believes we are sometimes isolated due to intimacy. We are afraid of rejections such as being turned down or our partners breaking up with us. We are familiar with pain and to some of us rejection is so painful that our egos cannot bear it. Erikson also argues that "Intimacy has a counterpart: Distantiation: the readiness to isolate and if necessary, to destroy those forces and people whose essence seems dangerous to our own, and whose territory seems to encroach on the extent of one's intimate relations" (1950).
Once people have established their identities, they are ready to make long-term commitments to others. They become capable of forming intimate, reciprocal relationships (e.g. through close friendships or marriage) and willingly make the sacrifices and compromises that such relationships require. If people cannot form these intimate relationships—perhaps because of their own needs—a sense of isolation may result; arousing feelings of darkness and angst.
Care: generativity vs. stagnation (adulthood, 40–64 years)
- Existential Question: Can I Make My Life Count?
Generativity is the concern of guiding the next generation. Socially-valued work and disciplines are expressions of generativity.
The adult stage of generativity has broad application to family, relationships, work, and society. "Generativity, then is primarily the concern in establishing and guiding the next generation... the concept is meant to include... productivity and creativity."
During middle age the primary developmental task is one of contributing to society and helping to guide future generations. When a person makes a contribution during this period, perhaps by raising a family or working toward the betterment of society, a sense of generativity—a sense of productivity and accomplishment—results. In contrast, a person who is self-centered and unable or unwilling to help society move forward develops a feeling of stagnation—a dissatisfaction with the relative lack of productivity.
- Central tasks of middle adulthood
- Express love through more than sexual contacts.
- Maintain healthy life patterns.
- Develop a sense of unity with mate.
- Help growing and grown children to be responsible adults.
- Relinquish central role in lives of grown children.
- Accept children's mates and friends.
- Create a comfortable home.
- Be proud of accomplishments of self and mate/spouse.
- Reverse roles with aging parents.
- Achieve mature, civic and social responsibility.
- Adjust to physical changes of middle age.
- Use leisure time creatively.
Wisdom: ego integrity vs. despair (maturity, 65 – death)
- Existential Question: Is it Okay to Have Been Me?
As we grow older and become senior citizens we tend to slow down our productivity and explore life as a retired person. It is during this time that we contemplate our accomplishments and are able to develop integrity if we see ourselves as leading a successful life. If we see our life as unproductive, or feel that we did not accomplish our life goals, we become dissatisfied with life and develop despair, often leading to depression and hopelessness.
The final developmental task is retrospection: people look back on their lives and accomplishments. They develop feelings of contentment and integrity if they believe that they have led a happy, productive life. They may instead develop a sense of despair if they look back on a life of disappointments and unachieved goals.
This stage can occur out of the sequence when an individual feels they are near the end of their life (such as when receiving a terminal disease diagnosis).
- Psychosocial Crises: All first eight stages in reverse quotient order
Joan M. Erikson, who married and collaborated with Erik Erikson, added a ninth stage in The Life Cycle Completed: Extended Version. Living in the ninth stage, she wrote, "old age in one's eighties and nineties brings with it new demands, reevaluations, and daily difficulties". Addressing these new challenges requires "designating a new ninth stage". Erikson was ninety-three years old when she wrote about the ninth stage.
Joan Erikson showed that all the eight stages "are relevant and recurring in the ninth stage". In the ninth stage, the psychosocial crises of the eight stages are faced again, but with the quotient order reversed. For example, in the first stage (infancy), the psychosocial crisis was "Trust vs. Mistrust" with Trust being the "syntonic quotient" and Mistrust being the "diatonic". Joan Erikson applies the earlier psychosocial crises to the ninth stage as follows.
"Basic Mistrust vs. Trust: Hope"
In the ninth stage, "elders are forced to mistrust their own capabilities" because one's "body inevitably weakens". Yet, Joan Erikson asserts that "while there is light, there is hope" for a "bright light and revelation".
"Shame and Doubt vs. Autonomy: Will"
Ninth stage elders face the "shame of lost control" and doubt "their autonomy over their own bodies". So it is that "shame and doubt challenge cherished autonomy".
"Inferiority vs. Industry: Competence"
Industry as a "driving force" that elders once had is gone in the ninth stage. Being incompetent "because of aging is belittling" and makes elders "like unhappy small children of great age".
"Identity confusion vs. Identity: Fidelity"
Elders experience confusion about their "existential identity" in the ninth stage and "a real uncertainty about status and role".
"Isolation vs. Intimacy: Love"
In the ninth stage, the "years of intimacy and love" are often replaced by "isolation and deprivation". Relationships become "overshadowed by new incapacities and dependencies".
"Stagnation vs. Generativity: Care"
The generativity in the seventh stage of "work and family relationships", if it goes satisfactorily, is "a wonderful time to be alive". In one's eighties and nineties, there is less energy for generativity or caretaking. Thus, "a sense of stagnation may well take over".
"Despair and Disgust vs. Integrity: Wisdom"
Integrity imposes "a serious demand on the senses of elders". Wisdom requires capacities that ninth stage elders "do not usually have". The eighth stage includes retrospection that can evoke a "degree of disgust and despair". In the ninth stage, introspection is replaced by the attention demanded to one's "loss of capacities and disintegration".
Living in the ninth stage, Joan Erikson expressed confidence that the psychosocial crisis of the ninth stage can be met as in the first stage with the "basic trust" with which "we are blessed".
Development of post-Freudian theory
Erikson was a student of Anna Freud, the daughter of Sigmund Freud, whose psychoanalytic theory and psychosexual stages contributed to the basic outline of the eight stages, at least those concerned with childhood. Namely, the first four of Erikson's life stages correspond to Freud's oral, anal, phallic, and latency phases, respectively. Also, the fifth stage of adolescence is said to parallel the genital stage in psychosexual development:
Although the first three phases are linked to those of the Freudian theory, it can be seen that they are conceived along very different lines. Emphasis is not so much on sexual modes and their consequences as on the ego qualities which emerge from each stages. There is an attempt also to link the sequence of individual development to the broader context of society.
Erikson saw a dynamic at work throughout life, one that did not stop at adolescence. He also viewed the life stages as a cycle: the end of one generation was the beginning of the next. Seen in its social context, the life stages were linear for an individual but circular for societal development:
In Freud's view, development is largely complete by adolescence. In contrast, one of Freud's students, Erik Erikson (1902–1994) believed that development continues throughout life. Erikson took the foundation laid by Freud and extended it through adulthood and into late life.
||This section may stray from the topic of the article. (November 2015)|
Erikson's theory may be questioned as to whether his stages must be regarded as sequential, and only occurring within the age ranges he suggests. There is debate as to whether people only search for identity during the adolescent years or if one stage needs to happen before other stages can be completed. However, Erikson states that each of these processes occur throughout the lifetime in one form or another, and he emphasizes these "phases" only because it is at these times that the conflicts become most prominent.
Most empirical research into Erikson has related to his views on adolescence and attempts to establish identity. His theoretical approach was studied and supported, particularly regarding adolescence, by James E. Marcia. Marcia's work has distinguished different forms of identity, and there is some empirical evidence that those people who form the most coherent self-concept in adolescence are those who are most able to make intimate attachments in early adulthood. This supports Eriksonian theory, in that it suggests that those best equipped to resolve the crisis of early adulthood are those who have most successfully resolved the crisis of adolescence.
- Child development
- Developmental psychology
- Ethnic identity development
- Kohlberg's stages of moral development
- Positive disintegration
|Library resources about
Erikson's stages of psychosocial development
- Robert Mcg. Thomas Jr., "Joan Erikson Is Dead at 95; Shaped Thought on Life Cycles," New York Times obituary, August 8, 1997. Online at https://www.nytimes.com/1997/08/08/us/joan-erikson-is-dead-at-95-shaped-thought-on-life-cycles.html.
- Crain, William (2011). Theories of Development: Concepts and Applications (6th ed.). Upper Saddle River, NJ: Pearson Education, Inc. ISBN 978-0-205-81046-8.
- Macnow, Alexander Stone, ed. (2014). MCAT Behavioral Science Review. New York City: Kaplan Publishing. p. 220. ISBN 978-1-61865-485-4.
- Bee, Helen; Boyd, Denise (March 2009). The Developing Child (12th ed.). Boston, MA: Pearson. ISBN 978-0-205-68593-6.
- Axia College Materials (2010)
- "Stages of Social-Emotional Development – Erik Erikson". childdevelopmentinfo.com. Child Development Institute. Retrieved 8 May 2015.
- Allen, Eileen; Marotz, Lynn (2003). Developmental Profiles Pre-Birth Through Twelve (4th ed.). Albany, NY: Thomson Delmar Learning. ISBN 978-0-7668-3765-2.
- Gross, Francis L. (1987). Introducing Erik Erikson: An Invitation to his Thinking. Lanham, MD: University Press of America. p. 47. ISBN 0-8191-5788-0.
- Wright, Jr, J. Eugene (1982). Erikson: Identity and Religion. New York, NY: Seabury Press. p. 73. ISBN 0-8164-2362-8.
- Stevens, Richard (1983). Erik Erikson: An Introduction. New York, NY: St. Martin's Press. pp. 48–50. ISBN 978-0-312-25812-2.
- Slater, Charles L. (2003), "Generativity versus stagnation: An elaboration of erikson's adult stage of human development", Journal of Adult Development, 10 (1): 53–65
- Erik H. Erikson, Joan M. Erikson, The Life Cycle Completed: Extended Version (W. W. Norton, 1998).
- Erik H. Erikson, Joan M. Erikson, The Life Cycle Completed: Extended Version (W. W. Norton, 1998), 4, 105.
- James Mooney, "Erik Erikson" in Joe L. Kincheloe, Raymond A. Horn, editors, The Praeger Handbook of Education and Psychology, Volume 1 (Praeger, 2007), 78.
- Erik H. Erikson, Joan M. Erikson, The Life Cycle Completed: Extended Version (W. W. Norton, 1998), 106.
- Erik H. Erikson, Joan M. Erikson, The Life Cycle Completed: Extended Version (W. W. Norton, 1998), 106-107.
- Erik H. Erikson, Joan M. Erikson, The Life Cycle Completed: Extended Version (W. W. Norton, 1998), 107-108.
- Erik H. Erikson, Joan M. Erikson, The Life Cycle Completed: Extended Version (W. W. Norton, 1998), 109.
- Erik H. Erikson, Joan M. Erikson, The Life Cycle Completed: Extended Version (W. W. Norton, 1998), 109-110.
- Erik H. Erikson, Joan M. Erikson, The Life Cycle Completed: Extended Version (W. W. Norton, 1998), 110-111.
- Erik H. Erikson, Joan M. Erikson, The Life Cycle Completed: Extended Version (W. W. Norton, 1998), 111-112.
- Erik H. Erikson, Joan M. Erikson, The Life Cycle Completed: Extended Version (W. W. Norton, 1998), 112-113.
- Erik H. Erikson, Joan M. Erikson, The Life Cycle Completed: Extended Version (W. W. Norton, 1998), 112-113.
- Wrightsman, Lawrence S. (1994). Adult Personality Development. Thousand Oaks, CA: Sage Publications, Inc. p. 61. ISBN 0-8039-4400-4.
- Erikson, Erik H. (1993) . Childhood and Society. New York, NY: W. W. Norton & Company. p. 242. ISBN 978-0-393-31068-9.
- Kail, Robert V. & Cavanaugh, John C. (2004). Human development: A life-span view (3rd ed.). Belmont, CA: Thomson/Wadsworth. p. 16. ISBN 978-0-534-59751-1.
- Erikson, Erik (1956). "The problem of ego identity" (pdf). Journal of the American Psychoanalytic Association. 4: 56–121. doi:10.1177/000306515600400104. Retrieved 2012-01-28.
- Marcia, James E. (1966). "Development and validation of ego identity status" (PDF). Journal of Personality and Social Psychology. 3: 551–558. PMID 5939604. doi:10.1037/h0023281. Retrieved 2012-01-28.
By: Leta Gurmessa Tafa July30,2016
- Erikson, E. (1950). Childhood and society (1st ed.). New York: Norton
- Erikson, Erik H. (1959) Identity and the Life Cycle. New York: International Universities Press.
- Erikson, Erik H. (1968) Identity, Youth and Crisis. New York: Norton.
- Erikson. Erik H. and Joan M. (1997) The Life Cycle Completed: Extended Version. New York: W. W. Norton
- Sheehy, Gail (1976) Passages: Predictable Crises of Adult Life. New York: E. P. Dutton.
- Stevens, Richard (1983) Erik Erikson: An Introduction. New York: St. Martin's.