Maturation

views updated Jun 11 2018

Maturation

MATURATION VERSUS DEVELOPMENT

CAVEATS ABOUT IDENTIFYING MATURATIONAL PROCESSES

MATURATIONAN EPIGENETIC PROCESS

MATURATIONTIMING AND SEQUENCE

CO-OCCURRENCE OF MATURATIONAL PROCESSES

LIFESPAN PERSPECTIVES ON MATURATION

BIBLIOGRAPHY

The term maturation comes from maturatio, a Latin word for ripening; thus, many dictionaries describe maturation as the process of becoming ripe or mature, and being mature as being ripe. In the social sciences, when we describe developmental changes as maturational, we are describing the change as having three characteristics: First, maturational change is an intrinsically teleological or endgoal oriented process. Second, maturational change is a systematic process. Finally, the end-goal of maturational change is an adaptive state. Maturity represents this goallike apex of adaptive functioning, and maturation describes the systematic and time-consuming processes that achieve maturity. Consequently, maturity does not just happen; it is a time-consuming and organized growth process.

This definition of maturation is broader than it has been defined historically. For example, the Child Study Movement of the first half of the twentieth century sought to describe child development as a maturational process that is independent of experience and learning. The goal of much of early developmental psychology (e.g., the work of Arnold Gessell and Nancy Bayley) was to chart the course of average and atypical child maturation. This approach, while providing information on the what and when of child development, does not explain why children develop as they do. Subsequent research has shown that human development is never a purely biological process. For example, there is a documented decrease of about four years in the age of menarche (the onset of menstruation in girls) in Europe and North America over the last century. This is called a secular trend (a trend over a long period of time) and appears to have leveled off in developed nations. However, in the United States there is some evidence that breast development is occurring earlier, although average age at menarche (twelve and one-half years) is not declining. Age at menarche is typically half a year later in most parts of Europe (thirteen years). Age at menarche in nations currently struggling with high rates of disease and malnutrition can be as high as seventeenwhere Europe was in the early 1800s. Environmental improvements in nutrition and disease control have the capacity to act on the genetically based timing of female reproductive maturation. Similarly, experiences such as paternal sexual abuse, chemical exposure, obesity, and ongoing stress can speed up pubertal development. On the other hand, severe caloric deprivation (e.g., an eating disorder or famine) can delay the onset of menarche, or even return an adolescent to prepubescent levels of hormonal functioning.

Development is multiply determined; genomes, physical environment, social environment, culture, adaptive history, and even our efforts to retain volitional control by the creation of meanings all contribute to the timing and expression of human development. Genetic code does not have sole control of even physical maturation; instead, the flexible capacity to act on the environment and be acted on by the environment is a core attribute of the human genome. It is increasingly apparent that no aspect of human psychological growth can be understood simply in terms of genetic input. In short, debates that push for allegiance to either nature or nurture no longer fit the data of human development.

Conceiving maturation as a purely biological process shares the same untenable assumption as nature versus nurture debates do; both assume that we can neatly untangle these forces. It is rather like trying to separate conjoined twins who share a brain or heart; each requires something owned by the other. Human development emerges out of dynamic interaction between forces inside and outside our bodies. Additionally, we must remember that there are also less deterministic players in the ringfor example, volition and the cognitive processes of meaning-making. Purely biological maturation is an impossibility. As Irving Gottesman and Daniel Hanson put it: Everything that is genetic is biological, but not all things biological are genetic (2005). We have probably underestimated the degree to which ever-popular nature-versus-nurture debates have blinded us to the profound and lively interaction of internal and external causes development. At best, these debates are artificial; at worst, they create a peculiar lens through which observations become myopic.

So where does this leave the word maturation ? Social scientists still use it to draw attention to biological aspects of development, but few would say they are speaking of purely genetically driven development. Is this word a historical artifactno longer precise enough for science? If we drop the purely biological restriction, does it become a simple synonym of development?

MATURATION VERSUS DEVELOPMENT

Although the term maturation is similar to the term development, from a lifespan perspective it is not synonymous with development. Unsystematic changes and declines can still be developmental changes, but they do not have the goal-based character of maturational change. For example, entropic changes toward lesser functionality and greater chaos are developmental changes, but not maturational because they are not systematic and teleological. Lifespan development is quite inclusive; it can include trajectories of gain or decline, systematic or chaotic processes, goal-directed or random ends. If we drop the dysfunctional aspects of maturations historic definition (i.e., excluding purely biological assumptions), maturation still includes only growthlike, purposeful, and maximally adaptive changes. For example, throughout a lifespan we find maturational growth in many domains of adaptation, but in the final years of life, nonmaturational developmental change increasingly overshadows maturational development. In contrast, maturational change dominates the pubertal, cognitive, emotional, and social developments of the first two decades of life. Declines of aging also have predictable developmental trajectories, but they less frequently include the systematic, goal-directed, adaptive changes characteristic of maturation. Ultimately death occurs because the organism, at all levels, can no longer maintain the goal-directed and systematic functions that preserve equilibrium.

CAVEATS ABOUT IDENTIFYING MATURATIONAL PROCESSES

When we designate a segment of development as a maturational change, we must remember that we have done just thatdesignated. Any dissection of human development into segments imposes onto it our own interests and timelines. In nature, maturation is an integrated whole, but when we describe maturation we would be overwhelmed if we did not focus on particular points of maturity within specific domains. For example, indicators of maturity and their maturational processes will differ depending upon whether one is looking at cognitive maturation, sexual maturation, or emotional maturation; each has its own maturity endpoint, yet in reality they are not as distinct as their separate titles would suggest. We may discuss them as separate maturational processes, but from the perspective of the developing organism (e.g., an adolescent), they are a single, dramatically integrated process.

A less obvious relativity is our choice of end goals or mature attributes. For example, the word ripe conjures images of fruit that has reached a stage of maturity we subjectively find delicious. Some say a mango is not ripe until it drops off the tree, because sweet and juicy is their conception of maturity. Others like mangos picked a little earlier because they prefer tangy mangos. A mango exporter defines maturity by factoring in shipping time and shelf life. The mango tree, if it could reflect on such things, might wonder at our fuss about its intact fruit; its goal is reproductionrotting, sprouting, and such things. Reflecting back on human development, if we value maximally efficacious child development, then a mother is reproductively mature when she herself has reached an acceptable level of psychological maturity. If, however, we are only concerned with basic sexual reproduction, then human females generally reach reproductive maturity during the year following menarche. Similarly, if the maturity or ripeness being defined is wisdom, our descriptions of what constitutes maturity and the processes needed to achieve maturation may vary considerably across cultures, religions, and historical period.

MATURATIONAN EPIGENETIC PROCESS

Maturation is an epigenetic process because it involves the emergence of new structures and functions through bidirectional relations between all levels of biological and experiential variables. According to Gottlieb: Individual development is characterized by an increase of complexity of organization (that is, the emergence of new structural and functional properties and competencies) at all levels of analysis (molecular, subcellular, cellular, organismic) as a consequence of horizontal and vertical coactions among the organisms parts, including organism-environment coactions (Gottlieb 1991, p. 7).

Genetic determinants of behavior are not fixed or immutable; rather, they have the capacity to respond adaptively, to turn off and on as required by circumstances. More than one gene determines the expression of most attributes, and each gene is embedded in a maturational system that is determined by a multitude of other genetic and environmental inputs. For example, Eric Turkheimer and his colleagues (2003) have found that the genetic heritability of intelligence is influenced by socioeconomic status. In impoverished families, shared environment explained most of the IQ variability among seven-year-old twins and almost none was explained genetically. They found the opposite among affluent families; shared genes accounted for most of the variation in intelligence, while environment accounted for very little. Only bidirectional influence between genetic, experiential, and volitional inputs, or epigenesis, can explain this apparent effect of socioeconomic status on genetic expression.

MATURATIONTIMING AND SEQUENCE

The fact that maturational timing is highly variable, while process or stage sequence is generally invariant, is a fascinating characteristic of the first two decades of life. For example, the sequence of motor skills developed before an infant is able to walk is quite consistent across individuals, but the rate at which infants learn to walk is quite variable. Similarly, pubertal maturation follows a predictable sequence of physical changes, but the rate of maturation is highly variable. One adolescent may start and finish pubertal development in a year, while another can take five years to go through the same sequence of change. The timing of female reproductive maturation is more sensitive to environmental and experiential inputs than is male reproductive maturation. This sequential regularity supports the inclusion of systematicity as a characteristic of maturation.

The timing of pubertal maturation has a significant impact on both male and female psychosocial adjustment. In Western cultures, girls who begin pubertal maturation ahead of their peers are more likely to experience depression, premature and exploitive sexual experiences, delinquency, low academic achievement, and school dropout. Because a heavier body type is associated with early pubertal maturation, these girls also experience more body image disturbances and eating disorders. However, early-maturing girls attending same-sex schools do not seem to experience these problems. Boys who mature early experience life differently; they tend to be given more leadership experience, have more success in sports, attract more positive female attention, and have more confidence. The downside of early male pubertal development is greater involvement in delinquent behavior and substance abuse. There is little negative impact of late development on girls. They tend to have the slimmer body type preferred in Western cultures, thus avoiding the body image problems of early developers. Their academic achievement is also significantly higher than that of their early-developing peers. Late-developing boys have more difficulty, with less confidence and more depressive affect, but they do tend to be more creative and achieve more in the end.

CO-OCCURRENCE OF MATURATIONAL PROCESSES

Maturational processes can be correlated or uncorrelated despite occurring during the same period of life. For example, pubertal maturation and the final stages of musculoskeletal and cardiovascular maturation generally co-occur. Other co-occurring maturational processes can be quite independent of each other. For example, the timing of pubertal maturation and adolescent cognitive maturation seem to be unrelated. Adolescent pubertal maturation and its influence on emotion processing (e.g., limbic system) can occur before, during, or after the prefrontal cortex maturation that underlies gains in abstract thinking and self-regulation. Consequently, adolescents whose pubertal maturation precedes their cognitive development are more vulnerable to risk-taking and poor social choices because they have the drives and emotions of puberty without the cognitive maturity to help control their expression.

LIFESPAN PERSPECTIVES ON MATURATION

Developmentalists also use maturation to describe the attainment of skills and capacities achieved later in life. For the adult, both the domains of maturation and the level of maturation reached become individualized. One adult may focus on attaining mature financial skills, while another may focus on attaining mature interpersonal skills or wisdom. Experiential opportunities and demands do play a stronger role in adult maturation than they do in childhood, but genetic input is still substantial. Both genes and prior developmental outcomes contribute to cognitive and physical capacity, and choice of environments, experiences, and acquaintances. Another input that may grow in strength across adulthood is volition. The adult capacity for meaning making and thus control over choices creates maturational opportunities that are not available to the young. These opportunities increase individual differences in both areas of competence and the levels of skill (maturity) reached. These individual differences are part of the study of personality and the study of clinical and counseling applications. For all of these areas, maturity refers to maximally adaptive social, emotional, or cognitive functioning, and maturation is the process of achieving it.

SEE ALSO Child Development; Children; Developmental Psychology; Malnutrition; Nutrition; Undereating

BIBLIOGRAPHY

Gottesman, Irving I., and Daniel R. Hanson. 2005. Human Development: Biological and Genetic Processes. Annual Review of Psychology 56: 263286.

Gottlieb, Gilbert. 1991. Experiential Canalization of Behavioral Development: Theory. Developmental Psychology 27: 413.

Turkheimer, Eric, Andreana Haley, Mary Waldron, et al. 2003. Socioeconomic Status Modifies Heritability of IQ in Young Children. Psychological Science 14 (6): 623628.

Joan M. Martin

Maturation

views updated May 18 2018

MATURATION

Maturation, in the broad sense, means all of the processes in the course of the development of an organism that lead it to a mature state. In a more precise sense, it can be taken to mean the set of preprogrammed mechanisms that set in motion and coordinate the functions necessary for the life of the organism, before they come into operation, and for which biological maturation creates the means and conditions.

The term has made only marginal appearances in psychoanalytic literature. It would seem that Freud never used it in his writings, as evidenced by its absence in James Strachey's detailed index to the Standard Edition.

However, Donald W. Winnicott called one of his books The Maturational Processes and the Facilitating Environment, but, as the title itself indicates, the term is used with the broad understanding that most of the work on mental development could be considered to be studies of maturation. With explicit references to embryogenesis, René Spitz (1979) attempted to describe the organizers that preside over the succession of maturative stages of the mind (the first smile, walking, language)these organizers themselves being preprogrammed.

From a totally different angle, the adjective maturing is sometimes used to characterize some of an analyst's interpretations in the course of the treatment, in a sense similar to what led James Strachey in 1969 to refer to mutative interventions. Here the term is used to designate interpretations that favor the process of maturation in the treatment through a reorganization of the psychic apparatus.

Roger Perron

See also: Adolescence; Archetype (analytical psychology); Genital love; Libidinal development; Imaginary identification/symbolic identification; Integration; Parenthood; Premature/prematurity; Puberty; Stage (or phase); Time; Transgression.

Bibliography

Spitz, René. (1979). L'embryologie du moi. Une théorie du champ pour la psychanalyse. Paris: Complexe.

Strachey, James. (1969). The nature of the therapeutic action of psycho-analysis. International Journal of Psycho-Analysis, 50 (2), 275-291.

Winnicott, Donald W. (1965). The maturational processes and the facilitating environment. London: Hogarth and the Institute of Psycho-Analysis.

Maturation

views updated May 18 2018

MATURATION

Arnold Gesell, a psychologist, pediatrician, and educator in the 1940s, was very interested in child development. From his numerous observations of children, Gesell formulated a theory known as maturation. This theory stated that developmental changes in a child's body or behavior are a result of the aging process rather than from learning, injury, illness, or some other life experience. Gesell's idea of maturation was rooted in the biological, physiological, and evolutionary sciences. As a result, Gesell centered most of his theory on the power of biological forces, which he felt provided momentum for development to occur. Gesell and his contemporaries proposed that development follows an orderly sequence and that the biological and evolutionary history of the species decides the order of this sequence. Maturation supports the idea that each child's unique genetic and biological makeup determines the rate of development regardless of other potential environmental influences.

See also:GESELL, ARNOLD; MCGRAW, MYRTLE BYRAM; MOTOR DEVELOPMENT; STAGES OF DEVELOPMENT

Bibliography

Salkind, Neil J. "Arnold Gesell and the Maturational Approach." Theories of Human Development. New York: D. Van Nostrand, 1981.

Shaffer, David R. "The Concept of Development." Developmental Psychology: Childhood and Adolescence, 4th edition. Pacific Grove, CA: Brooks/Cole, 1989.

Joan ZieglerDelahunt

maturation

views updated May 08 2018

maturation The evolution of hydrocarbons through the increasing pressure and temperature associated with burial. In the immature stage the product is gas; as it matures the development of heavy oils is succeeded by medium, and finally light oils. If the temperature exceeds approximately 100°C, however, dry gas is the sole product and the stage of incipient metamorphism is reached. See also NATURAL GAS; and PETROLEUM.

maturation

views updated May 17 2018

maturation
1. The process of becoming fully developed, especially the final phase in the development of germ cells, which renders the egg or sperm capable of fertilization.

2. Changes in the neuromuscular system as an animal develops that improve coordination regardless of experience.

maturation

views updated May 14 2018

maturation (mat-yoor-ay-shŏn) n. the process of attaining full development.