The nature-nurture debate

What is the nature-nurture debate about

Discussing how nature and nurture interact - an interactionist approach

What is an example of the NN debate

Bowlby claimed that a baby’s attachment type is determined by the warmth and continuity of parental love (an environmental influence) . Kagan proposed that a baby’s innate personality (temperament) also affects the attchment relationship. Therefore nature (child’s temperament) creates nurture (the parent’s response) so environment and heredity interact

What does the diathesis-stress model suggest

That behaviour is caused by a biological or environmental vulnerability (diathesis) which is only expressed when paired with a biological or environmental ‘trigger’

What are epigenetics

Refers to a change in our genetic activity without changing the genes themselves - it is a process that happens throughout life and is caused by interaction with the environment. Aspects of our lifestyle or events we encounter (from smoking and diet to trauma and war) leave 'marks' on our DNA (genes), which switch genes on or off. This explains why factors such as smoking have a lifelong influence even after you actually stop - they have changed the way your genes will be expressed

Why do epigenetics introduce a third element into the nature-nurture debate

Because they may go on to influence the genetic codes of our children, as well as their children - introduces the element of experience of previous generations

What does nature refer to

Heredity - the genetic transmission of both mental and physical characteristics from one gen to another. Early nativists argued that all human characteristics - and even some aspects of knowledge - are innate

What does nurture refer to

The influcence of experience and the environment. Empiricists argued that the mind is a blank slate at birth, which is then shaped by the environment. This view later became an important feature of the behaviourist approach

How is nature and nurture measured

The degree to which two people are similar on a particular trait can be represented by concordance - this provides an estimate about the extent to which a trait is inherited - called heritability

What is heritability and an example

Heritability explains how much of the variation in a specific trait (like height, intelligence, or eye color) within a group of people is due to genetic differences rather than environmental factors. A figure of .01 (or 1%) means genes contribute almost nothing to individual differences and 1.0 (or 100%) means genes are the only reason for individual differences.

The general figure for heritability in IQ is about .5 across multiple studies in varying populations (Plomin 1994). This means that about half of a person's intelligence is determined by genetic factors and the other half must be environmental

What is a strength

The use of adoption studies

Adoption studies are useful because they separate the competing influences of nature and nurture. If adopted children are found to be more similar to their adoptive parents, this suggests the environment is the bigger influence. Whereas, if adopted children are more similar to their biological parents (no influence on their environment), then genetic factors are presumed to dominate. A meta-analysis of adoption studies by Soo Rhee and Irwin Waldman (2002) found that genetic influences accounted for 41% of the variance in aggression

This shows how research can separate the influences of nature and nurture

What is a counterpoint to the previous evaluation point

Research suggests that separating nature and nurture is misleading. Robert Plomin (1994) argued that people shape their own "nurture" by choosing environments that suit their "nature." For example, an aggressive child may prefer to be around similarly aggressive peers, who then further influence their development. This process, called niche-picking, shows that nature and nurture are intertwined, making it pointless to focus on one without the other

What is a strength

An example of epigenetics comes from the Dutch Hunger Winter during World War II, when a Nazi blockade caused widespread famine, leading to 22,000 deaths. Ezra Susser and Shang Lin (1992) found that women who became pregnant during this time had low birth weight babies. More strikingly, these babies were twice as likely to develop schizophrenia as adults compared to the general population. This suggests that life experiences, like famine, can leave epigenetic markers that affect the health of future generations

What is another strength

Research shows that OCD is highly heritable, with Gerald Nestadt et al. (2010) estimating a heritability rate of 76%. This knowledge is useful for genetic counseling, as high heritability does not mean developing OCD is inevitable. People with a family history of OCD can be advised on their risk and ways to reduce it, such as managing stress. This highlights the practical importance of understanding the interaction between nature and nurture