How Genes and the Environment Operate to Influence Child Development Es

How Genes and the Environment Operate to Influence 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 p51]. 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 Mendal, [1865] showed that a plant’s single characteristic such as colour could be ‘inherited’ or altered though cross-hybridisation. That plants possessed individual traits ‘genes’ that could be altered and passed on to descendents. It wasn’t until DeVrise, Corrnens and Tschermak work in the twentieth centaury [cited in Sturtevant, 1965 and Weinsten, 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, DeFries, and McClern, 1990, cited in Richards, 1994 p214]. 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 evo... ...tes, J. [1994] ‘Infant Individuality’, in Oates, J (ed.) The foundations of development, Oxford, Blackwell/ The Open University p191. Thelen, E. [1992] 'Self-organisation in developmental processes: can a systems approach work?' in Johnson, M. H. (ed.) Brain Development and Cognition, Oxford, Blackwell. Cited in Richardson, K. [1994] ‘Evolution and Development’, in Oates, J (ed.) The foundations of development, Oxford, Blackwell/ The Open University p.69. Toulmin, S. [1971] 'Brain language: a commentary', Synthese, 22, pp. 369-95. Cited in Richardson, K. [1994] ‘Interactions in Development’, in Oates, J (ed.) The foundations of development, Oxford, Blackwell/ The Open University pp.221. Torrez, T. W. [1971] Morphogenesis of the Vertebrates, New York, Wiley. Cited in Richardson, K. [1994] ‘Evolution and Development’, in Oates, J (ed.) The foundations of development, Oxford, Blackwell/ The Open University p.62. Weinstein, A.[1977] How Unknown Was Mendel's Paper? Journal of the History of Biology 10, 341-364. Weismann, A. 1885 [1889]. Continuity of the Germ Plasm. In Essays upon heredity and kindred biological problems, ed. E. Poulton et al. Oxford: Clarendon Press.