Human Lifespan Development: Stages from Birth to Late Adulthood

Introduction to Lifespan Development

The process of human development is assessed according to multiple phases, each of which carries its own distinct set of expectations in terms of emotional growth, psychological development, physical maturation, and social awareness. With each phase also comes a distinct set of life-cycle considerations and a set of both socially and self-imposed pressures to participate in certain rites and elements of the life cycle. The intercession of these realities produces what are referred to in psychology and sociology as the stages of development. These stages tend to be distinguished from one another in a normally developing individual by an array of physical, mental, and sexual changes that will significantly shape the course of one's life.

The concept of emotional development is described in Erik H. Erikson's 1963 text, Childhood and Society. Here, the sociologist asserts that the ability of one's parents during the formative stages of life to earn the infant's trust will directly impact the success of his or her development. In elucidating the stages of emotional development that contribute to the mental and psychological growth of a human being, Erikson pays great attention to the matters of trust and nurturing.

Every person goes through many stages in life beginning at the time of conception, continuing throughout life, and ending in death. Human development is important to psychologists because it can provide insight about a person and the stage he or she may be experiencing in life, based on age-related changes in behavior, emotions, personality, and thought processes (Boyd & Bee, 2009). The study of changes throughout a person's life, from childhood through adulthood, has developed into a psychological area of study called the lifespan perspective. This modern perspective holds that interdisciplinary research is important for understanding lifespan development, and that each individual, of all ages, can change and develop through many different contexts (Boyd & Bee, 2009).

According to Annenberg Media Learner (2010), the following stages start at birth, although Boyd and Bee (2009) identify the prenatal period as the very first stage of development. The first period is birth to age two (infancy); the second is ages two through six (early childhood); the third is ages seven to nine (middle childhood); the fourth is ages ten to twelve (middle childhood); the fifth is ages thirteen to fifteen (adolescence); and the sixth is ages sixteen to nineteen (early adulthood). These first six stages all occur before age twenty, and a large amount of development takes place during these years. The seventh period is ages twenty to forty (emerging adulthood); the eighth period is forty to sixty-five (middle adulthood); and the last period is sixty-five and older (late adulthood). Considerable change and development occur during the adult years, though not as rapidly as in the younger years.

Prenatal and Infancy Stages

Theories within the lifespan perspective — such as Freud's or Erikson's psychosocial stages — are similar in age ranges but differ slightly. Each category under the lifespan perspective will vary somewhat within each theory and across the different domains of physical, cognitive, and social development. A key concern in the lifespan perspective is the nature versus nurture debate. In earlier decades, many developmentalists believed in only one or the other. It is only more recently that this perspective has shifted, and many now consider the factors of both nature and nurture in human development (Boyd & Bee, 2009).

One area of concern involves standard epidemiological methods that tend to discard the role genetics play in risk factors for disease, as well as genetic studies that ignore environmental risk factors. The National Institute on Alcohol Abuse and Alcoholism has conducted ongoing studies since the 1970s with adopted children, noting that adoptive environments could either facilitate or suppress the onset of alcohol abuse. A second area of concern is the context of development. According to Boyd and Bee (2009), it is important to examine the context in which a child and adult are changing — not solely within the immediate family, but also including the school, the neighborhood, the types of relationships the parents maintain with each other and others, and the parents' occupations and attitudes toward those occupations. Parenting style also plays a large role in child development. All of these factors interact with the personality traits of the individual to make each person's lifespan development unique.

In sum, the modern theory of human development lies within the lifespan perspective. It integrates research from different perspectives and areas of expertise and combines the influence of genetics with the influence of environment — both of which play a large role in an individual's progression through different stages of life. The lifespan perspective can be broken down into ten different stages of life, starting with conception, within three different domains: biological, cognitive, and psychosocial. The context in which a person progresses through life assimilates all aspects of each domain, interdisciplinary research, the multi-contextual nature of development, and the unique characteristics of the individual.

The womb is the first place a baby knows. During the later parts of pregnancy, when the cerebral cortex has developed and the fetus begins to gain a sense of awareness, recognition, and tactile sensation, the environment provided by the womb is critical to development. The unborn child will be affected by the safety, health, and equanimity of this environment — or by any conditions to the contrary. Syncresis (2009) indicates that there is a deep interconnection between the emotional orientation of the mother and the fetus, explaining that the emotionality of the mother carries the implicit potential for a profound influence on the child-to-be. If the mother is constantly anxious, fearful, depressed — or joyfully ecstatic — the embryonic child-body will be grown and molded by this prevailing affective environment and will be subtly but inexorably conditioned and programmed to live with and process, in utero, whatever emotional experience passes through the mother (Syncresis, 2009). This provides a consistent foundation for what is likely to occur during the child's infancy as well.

In infancy, the first crucial human relationship a person has is the one shared with his or her mother, already established in the prenatal stage. It is within the confines of this relationship that a child may be expected to develop feelings of security. In his text, Erikson asserts that "the firm establishment of enduring patterns for the solution of the nuclear conflict of basic trust versus basic mistrust in mere existence is the first task of the ego, and thus first of all a task for maternal care" (Erikson, 1963). This, he explains, is what enables the child to begin to experience a sense of comfort even while developing an awareness of his or her dependency on others. Constituted by the certainty that though the mother has left the room, she will soon return, a child comes into a sense of himself as he relates to other people according to the parameters of this first relationship. Trust, in this context, may be interchanged with confidence — a virtue gained on the strength of one's ability to first trust others and then, with maturation, to trust oneself.

Early and Middle Childhood

As explored throughout this discussion, the manner in which one experiences each stage of development will, Erikson believed, have a cumulative effect on the individual. In infancy, issues of trust and comfort are absolutely imperative to healthy development. The absence of these can have stultifying, even emotionally devastating effects on the development of the individual's ego orientation. According to Harder (2002), if one fails to develop trust — due to persistent frustration resulting from unmet needs — the individual will end up with a sense of worthlessness and will not feel secure in his or her environment. Researchers have also found that suicides and suicide attempts correlate with early developmental failures to accept, in a basic sense, that the world is trustworthy and that the individual belongs in it (Harder, 2002).

As the extreme consequences potential in the infancy period suggest, the rate of early childhood development is influenced as much by environmental surroundings as by individual capabilities. With the right framework and support structure, it is possible to facilitate proper socialization in a child, thereby encouraging the appropriate development of physical, emotional, and cognitive abilities. A suitable setting for these faculties also provides a stable basis by which to measure individual progress. The home environment plays a key role in shaping the early capabilities of children toward socialization and emotional stability, as do the first social contexts into which a child is introduced.

Erikson's view on early childhood was that this is a period of extremely dynamic integration of stimuli. He formulates that at this stage, children will learn to accept and work on mastering skills themselves — learning to walk, talk, and feed themselves, and developing finer motor skills, in addition to toilet training. Self-esteem and autonomy develop during this period, helping individuals learn to gain control over their bodies while acquiring new skills (Harder, 2002).

The effectiveness with which the child is able to navigate early childhood leads to the phase known as middle childhood, which is distinguished by the first identification of paths toward validation through positive personal relationships. The social tendencies, loyalty, and dedication that accompany the development of complex ethical cognizance all play a part in a phase that demands the refinement of social instincts, the development of problem-solving skills, and participation in more formal social activities. This stage serves as an ideal lens through which to observe the early emergence of both talents and challenges that will shape future learning patterns. The schemas encountered during early childhood may be integrated into more meaningful and self-directed views of the world. According to Huitt (2003), behavior and adaptation to the environment are controlled through mental organizations called schemes that the individual uses to represent the world and designate action. This adaptation is driven by a biological drive to obtain balance between schemes and the environment, a process Piaget called equilibration (Huitt, 2003).

It is during middle childhood that children begin to develop an understanding of moral schemes as something more complex than simply a matter of consequences. This conforms to Piaget's ideas about moral growth as it coincides with stages of development. Research has found that at about ten or eleven years of age, moral thinking in children undergoes significant modifications. Younger children base their moral judgments on consequences, while older children focus more on intentions. For example, when comparing a child who breaks fifteen cups accidentally and one who breaks one cup while trying to help, a young child will judge the first situation as worse because of the amount of damage. An older child will instead consider the motives and intentions behind the actions (Crain, 1985).

Conclusion: The Lifespan Perspective

This view of integrity is also what Erikson argues would allow individuals to make the final emotional and psychological preparations for the terminal stages of life. Healthy development and the achievement of self-actualization during adulthood would significantly factor into the ability of the individual to cope with the reality of his or her own mortality. For those who have achieved the meaning and identity required for personal contentment, Erikson argues that this stage should bring about a sense of acceptance for the inevitable.