The Nature-Nurture debate

Nature

The view that behaviour is a product of genetic or innate biological factors

Heredity

The process by which physical and psychological traits are genetically passed down from one generation to another (genetic inheritance)

Nurture

The view that behaviour is a product of environmental influences

Environment

Any influence on human behaviour that is not genetic, people, events and the physical world.This can include the environment in the womb through to cultural and historical influences

Interactionist-approach

The view that both nature and nurture interact and work together to shape human behaviour

Diathesis-Stress

A psychological theory that attempts to explain the cause of a disorder as the result of an interaction between a pre-dispositional vulnerability (diathesis) and a stress caused by life experiences

Neural plasticity

The brain’s tendency to change and adapt functionally and physically as a result of experience or learning

Outline the nature-nurture debate

is it more important to consider the relative contribution of genetic inheritance or environmental influences to best understand human behaviour

Which characteristics are positively correlated with genetic relatedness? And what had this led psychologists to assess?

• height, weight, hair loss, life expectancy and vulnerability to specific illness

• This has led psychologists to investigate whether psychological characteristics are innate

How do nativists explain characteristic and differences that are not observable at birth but which emerge later in life?

They say that they are the product of maturation, as we have a ‘biological clock’ which switches certain behaviours on or off in a pre-programmed way

Nature- attachment

• Bowlby- children are born biologically programmed to to form attachments because this will help them to survive.

• Attachment behaviours are naturally selected and passed on as a result of genetic inheritance (heredity)

• This theory is supported by research by Lorenz and Harlow using animals

• Supports influence of nature

Nature- OCD

• Family, twins and adoption studies show that the closer the relatedness of two people the more likely it is that they will show the same behaviours

• Carey and Gottesmann found that monozygotic twins have higher concordance rates for OCD (87%) than dizygotic twins (47%), suggesting that genetics (nature) play a role

• This emphasises the importance of the contribution of genetics on behaviour and therefore provides evidence for the nativist position

What is the nurture view?

Behaviour is the product of environmental influences

Assumption of environmentalists/empiricists

Human mind is tabula rasa (a blank slate) and is gradually ‘filled’/shaped as a result of experience

Who first proposed the nature approach and who took it up?

John Locke and the view was then taken up by behavioural psychologists, e.g. Watson

How do environmentalists explain psychological characteristics and behavioural differences that emerge during infancy and childhood?

They are a result of learning

Nurture- attachment

Behavioural psychologists explain attachment in terms of classical conditioning

Food (UCS) is associated with mother (NS) and through many repeated pairings mother becomes a conditioned stimulus, who elicits a conditioned response of pleasure in the child

Child forms an attachment based on the pleasure experienced as a result of being fed

demonstrates role of nurture

Nurture- phobias

• environmental explanations of conditioning can be used to explain phobias

• Classical conditioning- negative experience(UCS) with phobic stimulus(NS) - phobia (CS) leading to fear (CR)

• Operant conditioning- maintains phobias- negative reinforcement- avoid situations in which phobic stimulus may be present in order to avoid anxiety and fear, reinforces phobia

• Role of nurture and environment in developing psychological disorders

Gene environment interaction

Interplay of genes (and more broadly genome function) and the physical and social environment

Passive Gene Environment interaction

Parents contribute to their child’s development by passing on their genes and providing an environment for the genetic predisposition to develop

Active Gene environment interaction

Child’s inherited traits lead them to make choices about their environment, known as niche picking or constructivism

AO3- active gene environment interaction

P- too complex to separate the debate- nature can impact our nurture

E- E.g. Plomin suggested active gene environment interaction. (Constructivism). People can construct their own environment and create their ‘nurture’ by actively selecting environments suitable for their nature. For example,

• Niche picking- picking an env that suits nature (e.g. person who loves reading joins a book club)

• Niche building- construct/build/change environment to better suit genes- (e.g. build a network of book lovers)

E- Scarr and McCartney- constructivism has more impact as we age. This is because we can’t pick niches as children as our parents encourage hobbies/choose schools . Over time active niche building has more impact on behaviour (e.g. can pick uni/subjects/job when older)

L - demonstrates interaction between nature and nurture

AO3- nurture impacts nature

P- influence may work in the other direction- life experiences impact our nature

E- neuroplasticity= changes in the structure of the brain (nature) as a result of life experience (nurture)

E- Maguire er al- investigated the volume of the hippocampus in the brains of London taxi drivers. Posterior hippocampus (involved in spatial skills) larger in taxi drivers compared to non-taxi drivers. The rigorous training of learning streets and routes as well as experience driving the taxi (nurture) influenced the size of the hippocampus (nature)

L- supports the theory of neuroplasticity and the interaction of nature and nurture

AO3- interactionist approach

P- too simplistic to consider nature and nurture in isolation of one another, adopt an interactionist approach instead. -understand that nature and nurture come together to influence behaviour as it is not possible to separate them

E- interactionist models such as diathesis-Stress models of mental illness consider interaction of these two factors. Diathesis (predisposed vulnerability e.g. genes), stress (life stressors)

E- e.g. in OCD those who inherit a biological predisposition e.g. SERT or COMT candidate genes are more vulnerable to OCD but OCD will only be triggered by a stressor in the environment. Research has suggested that not everyone with these candidate genes goes on to develop OCD and this interaction with the environment is needed.

L- Diathesis-Stress model states that it is impossible to say which is more important nature or nurture, as for nurture to be expressed nature must be involved. More useful and holistic way to explain mental illnesses