4. the nature - nurture debate

Question 1

NATURE
Refers to

Answer 1

inherited influences (heredity).
All human characteristics are innate. Psychological characteristics like intelligence or personality are determined by biological factors (genes), just like physical characteristics like eye colour is.

Question 2

NURTURE
Refers to

Answer 2

the influence of experience and environment. Empiricists argue that the mind is a blank slate at birth which is then shaped by the environment. This view became an important feature of the behaviourist approach.

Question 3

Lerner has identified different levels of the environment which includes

Answer 3

prenatal factors, such as how physical influences like smoking or psychological influences like music affects a foetus. More generally development is influenced postnatally in terms of social conditions the child grows up in.

Question 4

MEASURING NATURE AND NURTURE
The degree to how two people are similar on a particular trait can be represented by a correlation coefficient and is called concordance.
Such concordance provides an estimate about the extent to which a trait is inherited - this is called

Answer 4

heritability - the proportion of differences between individuals in a population, with regards to a particular trait due to genetic variation.

Question 5

A figure of .01 (1%) means x and 1.0 (100%) means y

Answer 5

x genes contribute almost nothing to individual differences
y genes are the only reason for individual differences.

Question 6

Plomin found the general figure for heritability in IQ is about

Answer 6

.5 – half a person’s intelligence is determined by genetic factors and the other half must be environmental.

Question 7

THE NATURE NURTURE DEBATE
Seeks to answer the question of

Answer 7

whether our behaviour is more influenced by nature or nurture.

Question 8

THE INTERACTIONIST APPROACH

bowlby / kagan

Answer 8

Discusses how nature and nurture interact.
For example, Bowlby claimed a baby’s attachment type is determined by the warmth and continuity of parental love (nurture), whereas Kagan proposed that a baby’s innate personality (nature) affected the attachment relationship thus, nature (the child’s temperament) creates nurture (the parents’ response). This shows environment and heredity interact.

Question 9

DIATHESIS-STRESS MODEL

use ocd as an example

Answer 9

Suggests behaviour is caused by a biological or environmental vulnerability (diathesis) which is only expressed when it is couples with a biological or environmental trigger (stressor).
e.g. a person who inherits genetic vulnerability for OCD may not develop the disorder, but might develop the disorder if it’s combined with a psychological trigger, like a traumatic experience.

Question 10

EPIGENETICS

Answer 10

Refers to a change in our genetic activity without changing genes themselves - it is caused by interaction with the environment.
e.g. smoking leaves marks on our genes which switch genes on or off - explains why smoking has a lifelong impact even after a person stops smoking.
evolutionary theory also predicts these markers can be transferred through generations.

Question 11

AO3: strength of nature nurture

ADOPTION STUDIES - Waldman (aggression)

Answer 11

The use of adoption studies supports the nature-nurture debate.
Adoption studies are useful because they separate the competing influences of nature and nurture - if adopted children are found to be more like their adoptive parents, this suggests the environment is the bigger influence. Whereas, if adopted children are more similar to their biological parents, then genetic factors are presumed to dominate. A meta-analysis of adoption studies by Waldman found that genetic influences accounted for 41% of variance in aggression.
This shows how research can separate the influences of nature and nurture.

Question 12

AO3: strength of nature nurture

REAL WORLD APPLICATION - Nestadt (OCD)

Answer 12

Nature-nature debate has real world application.
Research suggests that OCD is a highly heritable mental disorder. Nestadt et al. put the heritability coefficient at .76. Such understanding can inform genetic counselling because it is important to understand that high heritability does not mean it is inevitable that the individual will go on to develop the disorder. This means that people who have a high risk of developing OCD because of their family background can receive advice about the likelihood of developing the disease and how they might prevent it (learning to manage stress).
This shows that the debate is not just a theoretical one, but it is important at a practical level to understand the interaction between nature and nurture.

Question 13

AO3: limitation of nature nurture

NATURE-NURTURE CANNOT BE SEPERATED - Plomin

Answer 13

However, research suggests that this approach may be misguided.
Nature and nurture are not two entities that can simply be pulled apart. According to Plomin, people create their own nurture by actively selecting environments that are appropriate for their nature. For example, a naturally aggressive child is likely to be more comfortable with children who show similar behaviours and choose their environment accordingly, which will then further influence their development. Plomin refers to this as niche-picking.
This suggests that it does not make sense to look at evidence of either nature or nurture.