Physical And Psychological Characteristics Of Child Development example essay topic

CHILD DEVELOPMENT ED 209 BOOK 1: The Foundations of Child Development M A 02 Essay Option 2 Describe the processes by which genes and environment operate together to influence development. Discuss the significance of these processes for our understanding of child development. This essay will look firstly at the ideas that have prevailed throughout history, in relation to genes interacting with the environment, and the human developmental implications of this relationship. It will briefly outline the theory of Heritability, Evolution, Genetic Determination, Epigenesis, Developmental Plasticity and a 'transactional' model of development.

Secondly the theories of Genetic determination, Epigenesis and Developmental Plasticity will be compared. Physical and psychological characteristics of child development will illuminate the differing viewpoints held by these traditions. Anatomical development, temperament and language will be used as illustrators. Since the sixteen hundreds scholars interested in the origins of human formation; believed that humans had not changed since the creation of Adam. In essence what was needed to create a human was there at the point of conception, it just got bigger [Hartsoeker, 1694 cited in Richardson, 1994 p 51]. That all humans go through 'an unfolding' process during development, which is all part of a 'natural plan' this was referred to as 'Preformationism'.

These 'innate' processes or 'stages' were referred to as 'maturation' and this has developed from the philosophical position of 'Rationalism'. This position remained until the eighteen hundreds when biological developments challenged this position. Gregory Mendel, [1865] showed that a plant's single characteristic such as colour could be 'inherited' or altered though cross-hybridization. That plants possessed individual traits 'genes' that could be altered and passed on to descendants. It wasn't until Devise, Corrnens and Tschermak work in the twentieth centaury [cited in Sturtevant, 1965 and Weinstein, 1977] showed that single gene inheritance etc was responsible for evolutionary characteristics in humans, an example of single gene effects can be shown in the case of PKU [Phenylketonuria] which left untreated (not stopping Children with the mutated gene eating phenylalanine in their diet) would cause retarded intellectual development. [Plomin, De Fries, and McClern, 1990, cited in Richards, 1994 p 214].

It appears that Mendel's accomplishments on the laws of 'inheritance' were surpassed by the attention that was being given to the questions concerning the mechanism of evolution. [Bateson, 1909, Dunn, 1965]. By 1859 the Genetic and Epigenetic Paradigms had been proposed. Darwin's ideas being assimilated into popular culture while Lamarck's work languished in obscurity. Darwin's theory of Evolution proposed 'natural selection' and 'adaptation', that an organism could only change as a result of 'mutation', a change in the 'genotype' and that mutation had to 'infer' an advantage in the environment (phenotype) to be selected and therefore passed on. This process according to Darwin occurred below the level of consciousness [Darwin, 1859].

The organism is in essence 'blocked off' from its experience, leading to Weismann's idea of a 'barrier' [Weismann, 1885] and the central view of the genetic paradigm, which is 'reductionist ic'. Lamarck's theory alternatively, is of 'transformational' development, which results from the organism's experience of its environment [Lamarck, 1809]. Its prerequisite is that of the organism being 'open' to the experiences of its environment. 'Interaction' occurs at the genetic and environmental levels. Hence logically leading to the Epigenetic paradigm, which supports the same holistic, arrangements proposed by Lamarck [Burkhardt, 1977]. Two traditions with developmental implications were influenced as a result of the differing viewpoints of Darwin and Lamarck; they were Genetic Determination and Epigenesis.

Genetic Determination sees human development as reaching an 'endpoint'; this is in essence 'p reformational'. The environment is only there to explore where children's 'natural' abilities lie. Development is pretty much biologically 'pre-ordained' both in process and in endpoint. Enzymes make hand genes, which turn into hands [Torrez, 1971 p 243 cited in Richardson, 1994 p 62]. Developmental characteristics have no environmental input. The environment act as the canvas on which the painting will be painted, but the idea is already in the artists mind.

This is drawn from a 'Rationalist' tradition. Genetic Determination also subscribes to the idea that only genes that infer an adaptive advantage are passed on; Richard Dakwins emphasized this point when he coined the term 'selfish gene' [Dakwins, 1976]. Therefore environmental change adaptation under these circumstances would be very difficult [Plotkin and Odling-Smee, 1979 cited in Richardson p 64]. The implications on development are, it has a pre-ordained endpoint. Which is ok for physical characteristics such as feel, teeth respiratory organs etc., which are present in all members of the species; that the genes that code these characteristics are 'canalised' even in extreme environments [Mayr, 1970 cited Richardson, 1994 p 66].

There are therefore limitations on every characteristic that once ' an endpoint' is reached no more development can occur. Psychological characteristics however continue to develop. Genetic Determination would find it harder to explain personality, temperament, intelligence, knowledge and social adjustments, concepts which all imply that the environment is not 'static' but 'fluid' as are these characteristics [Richardson, 1994 p 64]. Epigenesist's on the other hand believe that during development a characteristic can be modified by 'feedback' from the environment, those genes have 'self organising' properties, which can be switched 'on' and 'off' in response to environmental changes.

This process allows a myriad of possibilities to occur in the same developmental characteristics [Ford, 1975, Mayr, 1970 cited in Richardson, 1994 p 66]. Piaget, [1980] referred to this as 'epi genetic systems' he used the example of differing living conditions of a species of water snail, which produced distinctly different shell shapes [Piaget, 1980 cited in Richardson, 1994 p 65]. Which basically means Epigenetic Development, occurs as a result of information over and above the information that is coded in the genes. That environmental information can be 'fed back' to the genes and that information can alter the genes, an example in humans is that of the 'immune system' [Plotkin & Odling-S mess, 1979 cited in Richardson, 1994 p 68].

Epigenesis is seen to occur in physical characteristic only during development i.e. when a hand is fully developed it can't grow another thumb because it would be more helpful [Thelen, 1992, Karmiloff-Smith, 1992 cited in Richardson, 1994 p 69]. Epigenesis is better suited to psychological development. Humans have to adapt to 'abstract' concept i.e. they have to 'learn' what is going on in the world i.e. 'cognitively' and they have to adapt to deal with theses situations. This can be seen in personality temperament intelligence described by Goodwin as '... make organisms independent of the environment by virtue of possessing internal copies of external pattern of variation' [Goodwin 1983 cited in Richardson, 1994 p 70]. Therefore humans develop through gene information interacting with the environment, which is interacting with information that is acquired through life. This is known as Developmental Plasticity, which are 'relaxed' genetic programs that are associated with change over the course of development, which is a 'construction list' model.

But there is one more step, social interactions. Humans have lived with others it has been estimated through reverse engineering since hunter-gatherer societies of 40 000 years ago. It has been suggested that the human brain has increased in size as an adaptation to cope with living within a human society [Richards, 1987 p 143 cited in Richardson, 1994 p 73] in which characteristics and skills such as 'tool manufacture' etc were required [Parker and Gibson, 1979 cited in Richardson, 1994 p 74] along with 'codes of conduct' which have evolved within human societal group [Lancaster, 1975, Richards, 1987 p 171, Dunn, 1988 cited in Richardson 1994, p 73]. Therefore the implications for children's psychological development under Epigenesis are genetic information interacts with the environment, which in turn interacts with information acquired throughout life that in turn interacts with information gained from others, this information is 'bi-directional'. The last part of the 'cycle' was proposed to be 'transactional'. Sameroff, [1991] proposed a 'transactional model' of development which can be demonstrated using the example of temperament [Richardson, 1994 p 240] that a complicated birth can produce anxiety in the mother which in turn produces anxiety in the child which can appear as a difficult temperament which produces avoidance in the parent which in turn produces developmental delay in the child through lack of contact with the parent which was demonstrated in Reading B [Berry-Brazelton and Cramer, 1991 cited in Stevenson and Oates, 1994 'Mary' p 208-9] All of the theories previously mentioned have their advocates as well as their critics.

This section will look at Genetic Determination verses an Epigenetic framework using child development as the arena. Physical development of an embryo to a newborn child is fairly well recognised as 'an unfolding' of genetic programs, humans are for example born with a 'rooting reflex' [Richardson, 1994 p 219]. This is to help locate food sources. Genetic determination would use this example of a 'reflexes' to state that this was an 'innate' process which would fit well within the rationalist tradition, both reflexes and physical characteristics as previously discussed fit well within this tradition; but they cannot explain more abstract concepts like temperament.

Temperament is seen, as being a 'steady state' within a 'fluid's ystem [Stevenson and Oates, 1994 p 170] thereby has no detectable endpoint. Temperament can better be described as epi genetic. Using a 'transactional' approach temperament can have quite far reaching implications on child development, according to Tizard and Hughes, 1984 [cited in Stevenson and Oates, 1994 p 191] children who are 'impulsive' and have 'short attention spans' can suffer both cognitively and socially due to the curbing of undesirable behaviour at school [Tizard and Hughes, 1984] and the same has been noted by Bates in relation to parental responses to different temperaments among their children [Bates, 1989 b cited Stevenson and Oates, 1994 p 192]. Lerner et al.

[1989] have also implied 'the goodness of fit' of a relationship has implications on child development. This basically states that if the child's character 'matches' or 'fits' with their social arrangements then the child will have positive interactions and will be positively socially adjusted. The reverse is true if the relationship with the key other / mother is maladjusted there will be negative consequences to child's long-term social adjustments [Lerner et al. 1989]. It has also been postulated that temperament has an influential effect on education and behaviour when dealing with stressful episodes, Quinton and Rutter used the example of pre-school children being hospitalized [Quinton & Rutter, 1976 cited in Stevenson and Oates, 1994 p 194].

A child's temperament can also have a very important impact on the type, range and quality of experiences they have [Scarr and McCartney, 1981 B] which will in turn effect what they learn from each experience [Rutter, 1982]. Genetic Determination could counter this argument by using the results of twin studies, in which if they could prove that genetically similar / identical individuals raised apart would resemble each other therefore removing experience as a factor [Plomin and Leohlin, 1989 cited in Richardson, 1994 p 227]. This could be countered by the heritability debate, that the methods adopted by the researchers to collect their data would be indistinguishable from genetic variations from environmental effects [Kamin, 1974 and Brofenbrennew, 1986]. Genetic Determination could respond by using the example of language, this is seen as 'an abstract' concept, and not a physical Characteristic.

That a child is seen by some to learn the semantics of a language. According to Non Chomsky humans development of physical and mental attributes are not qualitatively different [Chomsky, 1980 p 33 cited Richardson, 1994 p 219] he goes on to argue that environmental experience doesn't hold the 'richness' of experience that would be required to produce the prerequisite of learning a language [Chomsky, 1980] this point has also been emphasized by Fodor's, [1983] 'information-processing-modules' that are 'pre-wired' into the cognitive system to deal with 'concepts's uch as numbers, space etc. This could be counted by Geertz, 1962 '... A cultureless human being would probably turn out to be not an intrinsically talented thought unfulfilled ape, but a wholly mindless and consequently unworkable monstrosity.. ' [cited in Richardson, 1994 p 76]. On the whole what appears to be one ideology's strong point is the others weakness Genetic Determination 'as in Gesell's day shows that the precise mechanism by which genes work is still unclear' [Cain, 1992 Reading cited in Richardson, 1994 p 258]. That development 'unfolds' due to a pre-ordained course which reaches an endpoint has been shown to hold true for psychical characteristics and that theories relating to psychological characteristic such as Chomsky's can't be proven due to their theoretical nature which has little or no empirical evidence and alternative explanations from 'transactional' models can't be ruled out [Toulmin, 1971, Richards, 1992 cited in Richardson, 1994 p 221].

Developmental plasticity can only occur during childhood and not in later life [Thelen, 1992]. An end point to development can't be proven in psychological development, on the contrary psychological development is seen as ever changing and fluid [Parker and Gibson, 1979]. Each side appears to go only so far Genetic Determination fits well with specific physical 'adaptive' characteristics that have proven to be crucial for survival. Such as lungs, hearts etc that have been shown to exist over extreme environmental conditions where as Developmental Plasticity as a life long process fits better with psychological characteristics, which change throughout life this was illustrated by the temperament examples.

In conclusion both Genetic Determination and Epigenesis have far reaching implications for child development. Genetic determinism is better suited for explanations about physical development, all processes which reach an endpoint there is however a hole in the theoretical frame work about psychological development which don't appear to reach a disenable endpoint. Epigenesis and Developmental Plasticity alternative are better suited in dealing with psychological development as this appears to be built on layers of experience at the levels of personal and social experience which appears to be fluid throughout life. At the genetic-environmental level the organism may only develop until adulthood is reached and an endpoint to this development occurs; which also produces a theoretical whole. Until a theory is put forward that can take account of physical development reaching an 'endpoint' and psychological development remaining 'fluid' throughout life both Genetic Determination and Epigenesis / Developmental Plasticity have to remain in a state of uneasy co-existence.

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