Nature - Nurture Debate Flashcards
Environment
The environment is seen as everything outside the body, which can include people, events and the physical world.
Heredity
Heredity is the process by which traits are passed down genetically from one generation to the next.
Interactionist approach
An interactionist approach is the idea that biology (nature) and the environment (nurture) work together to determine behaviour.
Nature - nurture debate
The nature versus nurture debate is one of the oldest debates in psychology. It centres on the relative contributions of genetic inheritance and environmental factors to human development and behaviour
Nature
Behaviour is seen to be a product of innate (biological or genetic) factors
Nurture
Behaviour is a product of environmental influences
Introduction to nature and nurture debate
The nature versus nurture debate is one of the oldest debates in psychology. It centres on the relative contributions of genetic inheritance and environmental factors to human development and behaviour.
The influence of nature
Nature is the view that behaviour is the product of innate biological or genetic factors. For a long time, psychologists have known that certain physical characteristics, such as eye colour and skin pigmentation, and certain diseases (e.g. Huntingdon’s) are biologically determined and the result of heredity (or genetic inheritance). Heredity is the process in which traits are passed down from one generation to the next. Furthermore, characteristics like height, weight, hair loss, life expectancy and vulnerability to specific illnesses are positively correlated with genetic relatedness. This has led psychologists to investigate whether psychological characteristics are also “wired in” before we are born.
This is known as the nativist position, and the basic assumption is that the characteristics of the human species are a product of evolution and that individual differences are the result of each person’s unique genetic code. Early nativists such as Rene Descarte (1596-1650) argued that all human characteristics, and even some aspects of knowledge are innate (inborn).
Characteristics and differences that are not observable at birth, but which emerge later in life, are regarded by nativists as the product of maturation, as we have a ‘biological clock’ which switches certain behaviours ‘on’ or ‘off’ in a pre-programmed way. For example, Huntingdon’s disease is a genetically transmitted disorder that usually emerges between the ages of 30 and 50, although it can appear at any time, since the genetic cause is innately present.
Examples of nature argument in psychology
An example of the nature argument in psychology are family, twin and adoption studies which show that the closer the relatedness of two people, the more likely it is that they will show the same behaviours. For example, the risk of being diagnosed with schizophrenia is approximately 1% of the general population. However, Gottesman and Shields (1991) pooled the results of around 40 family studies and found that the risk increases to 46% for those with two parents who have schizophrenia. Also, Joseph (2004) pooled the data for schizophrenia studies conducted before 2001 and found an average concordance rate of 40% for MZ twins and 7% for DZ twins, highlighting a significant genetic component – supporting the idea that SZ may be caused by a genetic inheritance – nature.
Evolutionary explanations of nature debate
Evolutionary explanations also emphasise the importance of nature, as they assume that behaviours or characteristics that increase our chances of survival and reproduction will be naturally selected; the genes for these characteristics or behaviours will be passed on, as they provide an adaptive advantage. For example, Bowlby proposed that children come into the world biologically programmed to form attachments because this will help them to survive. This suggests attachment behaviours are naturally selected, and passed on as a result of generic inheritance (heredity mechanisms).
The influence of nurture
Nurture is the view that behaviour is the product of environmental influences. The environment is seen as everything outside the body which can include people, events and the physical world. Environmentalists (also known as empiricists) hold the assumption that the human mind is a tabula rasa (a blank slate) and that this is gradually ‘filled’ as a result of experience. This view was first proposed by John Locke in the 17th Century and was later taken up by behavioural psychologists. For example, John Watson (1913) famously wrote:
“Give me a dozen healthy infants, well-formed, and my own specified world to bring them up and I’ll guarantee to take any one at random and train him to become any type of specialist I might select–doctor, lawyer, merchant-chief, and yes, even beggarman and thief, regardless of his talents, penchants, tendencies, abilities, vocations, and race of his ancestors.”
According to environmentalists, psychological characteristics and behavioural differences that emerge through infancy and childhood are the result of learning.
Example of the nurture debate in psychology
For example, behavioural psychologists explain attachment in terms of classical conditioning, where food (unconditioned stimulus) is associated with the mother (neutral stimulus), and through many repeated pairings, the mother becomes a conditioned stimulus who elicits a conditioned response in the child. Therefore, the child forms an attachment based on the pleasure experienced as a result of being fed.
Bandura’s Social Learning theory argue that aggression is learned through observation, vicarious reinforcement and imitation, and is therefore explained by nurture (our environmental influences). However, he did acknowledge that the urge to behave aggressively might be biological, which suggests a more interactionist approach.
Environmental explanations of nurture debate
Environmental explanations can also partly explain the occurrence of schizophrenia. Bateson et al. (1956) proposed the double bind theory, which suggests that schizophrenia is the result of disordered communication within the family. This is where one instruction is given overtly to a child (e.g. a mother says ‘come to me’) while another instruction is given covertly (e.g. the mother’s manner and tone of voice are rejecting). Prolonged exposure to such interactions prevents the development of a coherent construction of reality, and in the long run this manifests itself as schizophrenic symptoms.
Advantages if nature - nurture debate
One strength of the nature-nature debate is The Interactionist Approach - recently psychologists have begun to question whether human behaviour is due to heredity factors (nature) or the environment (nurture). It is now widely accepted that heredity and the environment do not act independently and both nature and nurture are essential for almost all behaviour. Therefore, instead of defending extreme nativist or environmentalist views, most researchers are now interested in investigating the ways in which nature and nurture interact. The interactionist approach is the view that both nature and nurture work together to shape human behaviour.
Furthermore, the interactionist approach is best illustrated by the genetic disorder PKU (phenylketonuria). PKU is caused by the inheritance of two recessive genes, one from each parent. People with PKU are unable to break down the amino acid phenylalanine which builds up in the blood and brain causing mental retardation. However, if the child is diagnosed early, they are placed on a low protein diet for the first 12 years, which helps to avert this potentially lifelong disorder. Therefore, the disorder PKU (nature) is not expressed, because of an altered environment (low protein diet – nurture).
Another strength of the nature-nurture debate is epigenetics – This refers to a change in our genetic activity without changing our genetic code. It is a process that happens throughout life and is caused by interaction with the environment. Aspects of our lifestyle, and the events we encounter – from smoking and diet to pollution and war – leave epigenetic ‘marks’ on our DNA. These marks - like highlighted text or bookmarks, tell our bodies which genes to ignore and which to use, and in turn may influence the genetic codes of our children as well as their children. Epigenetics introduce a third element to the nature-nurture debate: the life experience of previous generations. Dias and Ressler (2014) gave male lab mice electric shocks every time they were exposed to the smell of acetophenone, a chemical used in perfume. As any behaviourist would predict, the mice showed a fear reaction as soon as the scent was presented. However, even the rats’ offspring also showed fear of the scent as well as the grandchildren! This shows the concept of epigenetics at work.
Another strength of the nature-nurture debate is that it supports neural plasticity which is another example of how nature and nurture interact. The brain can reorganise itself by forming new neural connections throughout life. Neuroplasticity is a term which describes the changes in the structure of the brain (nature), as a result of life experience (nurture). For example, Maguire et al. (2000) investigated the hippocampi volume of London taxi drivers’ brains. She found that the hippocampus on each side of the brain (and especially the right hippocampus) was larger in taxi drivers in comparison to non-taxi drivers. Consequently, Maguire concluded that driving a taxi (nurture) actually had an effect on the size of the hippocampi (nature).
A final strength of the nature-nurture debate is the argument that nature and nurture can interact in a variety of ways. Plomin et al. (1977) talks about active gene-environment interaction, a child’s heritable traits influence his or her choice of environment. For example, an aggressive child may choose to watch violent films and engage in contact sports. This is known as ‘nichepicking’ and shows how nature (genes) influences nurture (environment). In effect genes influence environment and the environment influences development. This influence increases with age. This argument would explain how an aggressive individual could end up committing violent crimes because of the choices they have made.
Disadvantages of nature - nurture debate
Nativists argue that ‘anatomy is destiny’ whilst the environment has little input – this determinist view led to controversy in linking race, genetics and intelligence and the application of the eugenics policy. – this suggests that we should be careful when blaming nature for peoples behaviour as it can lead to controversial policies which disadvantage certain members of society.
In contrast, but also controversially, empiricists would argue that any behaviour can be changed through behaviour shaping and modification which is possible through therapy – where good behaviours are reinforced and bad behaviours are ignored or punished - does that mean that we are puppets? Again we should be cautious in blaming nurture as we could end up being prisoners of our environment
