The influence of inborn biological factors and the contrasting aspect of environmental issues has been applied to many areas of psychology and development. The debate concerning nature and nurture has indeed become a central and enduring feature within developmental psychology. It addresses whether it is one’s innate biological nature that influences behavioural traits or if it is life experiences and nurture from the their social environment.
Classic psychology sought to establish firm evidence to discredit the involvement of one or the other of these influences. Modern psychologists however recognise that the origins of human behaviour cannot be referred to in such black and white terms. More recent research focuses on how both biology and environment interact to create the different psychological phenomena that we see and experience.Social development encompasses a number of areas with temperament, personality, gender development and aggression used in this piece. In the past psychologists have attempted to isolate environmental or biological aspects of a topic. The studies of feral children, adoption and twins have become important due to the apparent ability to separate the perceived influences in natural setting.
Reports of feral children focus on children who have been separated from their parents and ‘adopted’ as part of a family of mammals such as wolves or monkeys. The reliability of such information has been doubted but Ward (2002) argues that documented behaviour of children strongly supports the idea that upbringing is entirely responsible for a vast number of traits found to be common in the human population. Observed social behaviour in these children has highlighted issues such as a complete unawareness of the feelings of others, no emotional control, lack of attachment patterns, and no moral or value led beliefs. Although there is strong evidence for the environmental argument the feral children research does not allow us to discount genetic and biological traits in this instance. It is suggested that everyone has different inborn characteristics and the extent to which they display themselves is highly dependent on the environment in which a child is raised. (Nazli 1995)
Researchers have used the study of twins and adoption to assess the extent to which genetic factors play a part in areas of social development. By using identical twins who have been raised apart by adoptive families biologically identical individuals can be observed in different environments. A number of studies have shown that despite separated twins being subject to distinct environmental experiences there is still a strong concordance between twins and traits such as temperament (Gross et al 2000).
Additionally comparing identical and fraternal (dizygotic) twins allows examination of similarities in behaviour dependent on genetic closeness. Identical twins tend to show a higher level of correlation for temperament factors such as emotionality, activity and sociability in comparison to fraternal twins (Bee 2000)
Despite the strong evidence for biology in twin studies the rates of correlation between monozygotic twins are far from one hundred percent. If nature solely determined social development one would expect identical twins, being genetic replicas of one another, to show the exact same traits as one another. Although environment does undoubtedly play a significant part in social development the ways in which it interacts with inborn qualities has not yet been distinguished.
Feldman (2001) also argues that due to twin studies being natural experiments there are many control issues that affect the validity of research. For example Feldman suggests that where twins are placed in adoptive families the mother’s wishes and the interests of the children are took in to account. This can result in the twins growing up apart but in very similar environments.
Thomas and Chess (1982) produced early work on temperament that cites influences from both nature and nurture. They looked at a number of key dimensions of temperament including activity levels, inhibition, anxiety, persistence, control and emotionality. From this they developed three temperament types into which babies can be categorised. As these could be identified in new born babies Thomas and Chess suggested that temperament types were as a result of biological factors. Temperament in the long term however was seen as dependant on the nature and demands of the environment in which the child finds themselves in.
As with temperament, there is evidence to suggest that personality can be determined by inherent characteristics. Ebstein et al (1996) for example claims that there is a novelty seeking gene that exhibits some control on the amount of the chemical dopamine produced in the brain. The existence of a gene, such as for risk taking behaviour, would support biological arguments that seemingly social constructed traits have their roots in behaviour genetics.
In contrast to the biological viewpoint some of the oldest and most unethical experiments known in psychology are still used in evidence of just how much power the environment can exert on human behaviour. Watson and Rayner (1920) demonstrated how classical conditioning can cause enduring dispositions on the basis of learned behaviour. Behaviourists were typically of the belief that manipulation of learning patterns determined social development.
Schaffer (1996) argues however that biological and genetic factors at the time still provided a respected insight into the dimensions of personality. Modern behaviourism has taken the work from classic studies to propose that innate qualities can be reinforced by their learning within their environment.
Looking further at personality Eley, Stevenson and Lichenstein (1999) provide input into aggressive and anti-social behaviour. Their findings from 1,500 pairs of twins advocate that aggressive behaviour can be inherited genetically but that the social environment also plays a significant role in how this develops. It was found that non aggressive behaviour is reinforced in many environments and that this can in turn impact on someone who has a biologically high tendency to exhibit aggression. Schaffer (1996) noted that hormones and other biological aspects have been implicated in the occurrence of aggression however no definite conclusion has been reached in terms of what extent they interact with the social environment.
Gender development and self concept are another aspect of social development that has been subject to the nature nurture debate. Money and Ehrhardt (1972) emphasised the social in their study of gender reassignment. The most prominent case looked at a set of male twins, one who suffered from deformed genitalia as a result of an unsuccessful surgical circumcision. The child was consequently raised as a girl. The child began to exhibit traits that were distinctly feminine and a significant difference was observed in behaviour compared to the child’s brother. Money and Erdhardt claimed that these differences were due to parental treatment and regarded the situation as a demonstration of how gender is socially generated. Bee (2000) however argues that many similar studies have resulted in psychological difficulties for those whose gender was reassigned contrary to their actual sex and that environment cannot solely shape a child’s gender concept. The premise here is that both biological gender and social gender exist.
Social development and developmental psychology foster many areas of possible research. What is apparent from relevant literature is that both biological and environmental approaches are supported by abundance of empirical research. Behaviour genetics are at an early stage but the traditional sciences are becoming increasingly more important in psychology. In turn social and environmental research is being used progressively more the investigation of deprivation and development in modern society. On the basis of this psychologists have tended to lean towards an interactionist position. Quite simply where all theories are taken into account and seen to operate individually and interact with one another (Baltes, Reese and Lipsett 1980)
Theorists have searched of ways to separate nature and nurture, but this very difficulty tells us that they cannot be separated so precisely. Rutter (1989) dismisses the idea of nature and nurture being separate as a myth. Although there is much to discover in relation to how nature and nurture interact modern psychology recognises that progression cannot be made without realisation of all factors that contribute to social development. Social development is a life process built upon a paradox.. at the same time we are both social and individual beings.