need points on 'nurture nature for future'?

Question

For making up of subject for an elocution

Answer 1

The nature-nurture debate goes by several names that are often used interchangeably in different sub-disciplines of psychology. These are nativism-empiricism (perception); maturation versus learning (developmental psychology); heredity versus environment (individual differences). Francis Galton began the nature-nurture debate when he referred to genes and environment as the two sources of individual differences in his study of giftedness (Hereditary Genius: An Inquiry into its Laws and Consequences, 1869). Until recently, the debate has remained rooted in the discipline of psychology. During the 1940s-1960s it was dominated by environmentalism through the influence of behaviourism and learning theory. However, with critical discoveries in molecular biology and genetics, made possible by the advent of sophisticated technologies, the new interdisciplinary fields of behavioural genetics and genetic epidemiology have emerged, and the importance of genetic contributions to development are becoming increasingly apparent. New challenges to accepted wisdom in the nature-nurture debate have grown apace since the 1960s, as the texts reviewed below will show. Most recent writing in the area views genes and environment as interdependent, recognising that genetic expression is always environmentally mediated and that genotypes moderate the effects of experience.


NATURE, NURTURE AND PSYCHOLOGY contains 24 chapters from eminent researchers in the field of developmental psychology and behavioural genetics. It begins with a brief historical exploration of the origin of the nature-nurture debate, followed by a discussion of the different questions this debate raises in each of the three main areas of inquiry: personality, cognitive ability, and psychopathology (focusing on depression, schizophrenia, alcoholism, autism, and attention deficit hyperactivity disorder). It concludes with a discussion of the role that behavioural genetics and new experimental paradigms will play in future research. Although dealing with difficult and complex issues, it is a very readable book, and provides an excellent overview of the key issues in the current debate.

This issue of ARCHIVES OF GENERAL PSYCHIATRY contains three articles and a commentary on the genetic epidemiology of psychiatric illness. Each article examines key questions related to the role of development, gene-environment interaction, and the familial environment in the aetiology of behavioural (aggression, anti-social behaviour, conduct disorder) and emotional disorders (major depression). The most intriguing article by Reiss et al, addresses the impact of differential parenting ie the effects of the differences in the ways in which parents treat their children on their children’s development of depression or antisocial behaviour. They found that parents treat their children similarly in the area of monitoring-control, but quite differently in conflict-negativity and warmth-support. They conclude that families are important for mental health, but that the influence derives from the unique features of individual parent-child relationships rather than from the generic familial environment.

MAGNUSSON contains a number of chapters of direct relevance to the nature-nurture debate, and these are tackled from a lifespan perspective. The first of these chapters, Genes and Environment (John C Loehlin) summarises the major findings from twin and adoption studies and synthesises them into succinct summaries. For intelligence, the message is that genes do not contribute much early in the lifespan but become increasingly important as people develop and age. The reverse effect is true of the environment. For personality, the moderate genetic influence on individual differences peaks in young adulthood and remains stable until late in life. The influence of shared family environment decreases over time until late adolescence. Gottlieb, in his chapter A systems View of Psychobiological Development, offers a four tiered model involving genetic, neural, behavioural, and environmental influences with bidirectional effects between each of the tiers. In their chapter, Cognitive Development, Weinert and Perner are concerned with what and in which form, knowledge is innately specified. Bellugi et al examine the same question using clues from genetically based syndromes; while Klein examines the genetically and socially transmitted knowledge related to language development. The final section of the book, Biology and Socialisation, offers fascinating insights into brain – behaviour, biology - culture relationships.

The nature-nurture debate as it relates to intelligence has been the most controversial and political of the three psychological domains to which this debate pertains because of the implications associated with any findings related to racial differences in IQ scores. This debate was ignited anew by the publication of The Bell Curve: Intelligence and Class in American Life by Hernstein and Murray in 1994. In response to the public furore created by this book, the American Psychological Association set up a task force chaired by NEISSER to provide an impartial, scientific report on the nature of intelligence. This excellent report first discusses the current conceptualisations of intelligence and then guides the reader through the complex maze of evidence related to both the genetic and environmental contributions to scores on IQ tests. This is followed by an analysis of the possible causes of differences in mean scores on IQ tests among different ethnic groups (Asian, Hispanic, and African Americans). A related paper on which much of the current race-IQ relationship debate is based is summarised in FLYNN, James. Searching for Justice: The Discovery of IQ gains over Time. American Psychologist, 54/1, (1999): 5-20.

This volume of CURRENT DIRECTIONS describes new research, using genetically sensitive strategies and methods in behavioural genetics, that unravels the nature/nurture puzzle in three domains: personality (see Saudino and Hamer) psychopathology (see Eley; Reiss; Boomsa, Anokhin, & de Geus) and cognitive abilities (see Petrill). Saudino challenges the accepted wisdom on the role of genetics in personality in three ways. Firstly, she argues that parental rating biases of identical and fraternal twins and siblings have resulted in an overestimate of genetic influence on the heritability of personality. Secondly, genetic factors may contribute to both situational variations in personality as well as to stability or continuity across situations. Thirdly, genetically influenced personality factors affect how people select, construct, or perceive their environments. That is, personality mediates the genetic contribution to environmental measures. Eley demonstrates the shared genetic influences on both internalising (ie anxiety and depression) and externalising (ie antisocial aggressive and non-aggressive behaviours) disorders in children. Petrill highlights the importance of genetic determinants of variance in cognitive ability across the lifespan, arguing that genetic evidence points to molarity, while the non-shared, individually experienced environment underpins modularity in cognitive function. Similarly, Reiss provides strong evidence of the importance of nongenetic, nonshared environmental influences on development. Boomsa addresses the relationships between genes, brain and behaviour by exploring the individual differences in brain electrical activity, the extent to which these differences are heritable, and the genetic risk associated with disorders such as schizophrenia and alcoholism. Finally, Hamer, a molecular biologist, searches for personality genes through linkage analysis that may contribute to diverse behavioural manifestations such as homosexuality and novelty seeking.

Early genetic research focused on discovering the relative contributions of nature and nurture on intelligence, concluding that there is strong evidence for the genetic influence on individual differences in intelligence, with heritability estimates averaging about 50%. Research has now moved into new areas, investigating issues related to change and continuity in intelligence throughout the lifespan, associations among different cognitive abilities, and the identification of specific genes that may be responsible for both cognitive abilities and disabilities. PLOMIN and PETRILL provide an exciting review of recent research and its findings. For example, using developmental genetic analysis, researchers have found that the genetic influence on intelligence increases with increasing age, doubling from about 40% in childhood to 80% in later life. Plomin and Petrill argue that "genetic dispositions nudge us towards environments that accentuate our genetic properties, thus leading to increased heritability throughout the lifespan (p 60)." For a more detailed discussion, see PETRILL, Stephen, PLOMIN, Robert, BERG, Stig, et al. The Genetic and Environmental Relationship between General and Specific Cognitive Abilities in Twins age 80 and Older. Psychological Science, 9/3, (1998): 183[-]189.

Answer 2

to save future you have to take care of nature.