Nature vs nurture Flashcards
the debate
Is a person’s development down to their genes or down to environmental influences.
key terms
Nature-nurture debate-Concerned with the extent to which aspects of behaviour are a product of inherited or acquired characteristics.
Nature-Innate influences on development / behaviour. This does not simply refer to abilities present at birth, but to any ability determined by genes, such as secondary sexual characteristics that appear at puberty or a condition such as Huntingdon’s disease which is usually only apparent in adulthood
Heredity-The genetic transmission of mental and physical characteristics from one generation to another.
Environment-Any influence on human behaviour that is non-genetic. This may range from pre-natal influences in the womb through to cultural and historical influences at a societal level.
Interactionist approach-The idea that nature and nurture are linked to such an extent that it does not make sense to separate the two, so researchers instead study how they interact and influence each other.
Examples of nature
Genetic Explanations
• E.g. Family, twin and adoption studies show that the closer two individuals are genetically, the more likely that both of them will develop the same behaviours. o The concordance rate of a mental disorder such as schizophrenia is about 40% for MZ twins and 7% for DZ twins.
• This closer similarity for individuals who share the same genes shows that nature has a major contribution to the disorder.
Evolutionary Explanations
• Natural selection - any behaviour or trait that promotes survival and reproduction will be naturally selected, as such behaviours and characteristics are adaptive and thus the genes for such behaviours will be passed onto subsequent
generations.
• E.g. Attachment (Bowlby) - adaptive because it promotes survival through protection. Also promotes close relationships which would foster successful reproduction.
- Therefore attachment behaviours are naturally selected, which can only be done through genetic mechanisms.
Examples of nurture
Behaviourism
• Behaviourists assume that all behaviour can be explained in terms of experience alone.
• E.g. Classical and operant conditioning.
- Attachment through food.
Social Learning Theory
- Bandura’s view is a little less extreme than traditional behaviourism. He also believed that behaviour was learned, but added the new dimension of indirect (vicarious) reinforcement.
• Bandura did also allow that biology had a role to play; for example, the urge to behave aggressively may be biological, but the point is that the way a person learns to express the anger is acquired through environmental influences.
Who wins
Nature-nurture question is impossible to answer.
• Environment influences a child’s life as soon as it begins.
• Nature and nurture are so intertwined that it makes no sense to separate the two.
• In twin studies it cannot be easily established whether high concordance rates are the result of shared genetics or shared upbringing.
• Psychologists now ask what the relative contribution of each influence is in terms of what we think and do.
limitation-nature and nurture can’t be separated
A limitation of the nature nurture debate is that many psychologists argue the two cannot be separated.
When asking which is more important, psychologist Donald Hebb said that this was like asking whether the width or length of a triangle was more important when measuring the area. They both contribute and therefore should never to considered separately.
E.g. Phenylketonuria, an inherited disorder that prevents amino acid phenylalanine being metabolised, resulting in brain damage. However, of the condition is detected at birth, an infant can be given a diet devoid of phenylalanine and thus the brain damage is averted.
If prevention can be achieved through environmental manipulation, is this condition due to nature or nurture?
Strength-diathesis stress model
The diathesis stress model conceptualises the interaction between nature and nurture.
This model is often used to explain mental disorders such as phobias or schizophrenia.
A diathesis is a genetic vulnerability, such as being born with certain genes that predispose a person to developing a disorder. However, research has shown that not everyone with those genes does develop the
disorder. Expression of the gene or genes depends on experience, in the form of a stressor, which triggers the condition. E.g. Trauma; life change etc.
Thus, a person’s nature is is only expressed under certain conditions of nurture and therefore the two interact.
Strength-natured affects nurture
Further support for the interaction between nature and nurture was suggested by Scar & McCartney, 1983
They suggested that genes may exert and indirect effect in a number of ways.
Passive interactions - the parents’ genes influence the way they treat their children. E.g.
Musically gifted parents are likely to play to their children and encourage engagement with music.
Evocative interaction - the child’s genes influence and shape the environment in which they grow up (the musically talented child will be picked for school concerts and given other special opportunities.
Active interaction - The child creates it’s own environment through the people and experiences it selects (the child itself chooses similar, musically talented friends and seeks out musical experiences).
Again, this points to a complex and multi-layered relationship between nature and nurture.
strength-shared and unshared environments
Teasing out the influence of the environment is complicated.
Even if you’re raised in the same family you may not experience exactly the same upbringing.
Dunn and Plomin (1990) introduced the idea of shared and unshared environments. Individual differences means siblings experience life events differently Eg. Age/temperament would mean a life event such as divorce would have a different meaning to each sibling. This would explain the finding that even MZ twins raised together don’t show perfect concordance rates
This supports the view that heredity and environment cannot be meaningfully separated.
