Nature vs Nurture

Intelligence

• The global capacity to act purposefully, think rationally and deal effectively with the environment.

Measuring IQ

• Intelligence Quotient
• (MA/CA) x 100 = IQ
• Scores are standardised according to a distribution pattern

Nature/Nurture debate

• Lack of agreement regarding the definition of intelligence
• Leads to debate over the origin of intelligenc

Nature

• Genetic component
• Fixed at birth
• Spearman's g factor

Nurture

• Environment eg schooling, family and culture.
• Humanistic/behavioural approaches eg Skinner, Bandura, Rogers & Maslow

Cultural differences

• No difference in IQ before school age, differences start after school.
• Indicates schooling has in impact on IQ
• Cultural expectations of academic achievement eg Japan
• Indirectly influences better performance on IQ tests

Nature vs Nurture: Australia

• Intelligence testing of Indigenous Australians
• Measures made of vision, hearing, reaction times before IQ tests were developed (late 19thC)
• No differences found between TSI and "educated" white people

Kearins (1986)

• Kim's game used both western/natural objects
• Aboriginal children performed better than white children

Cultural Bias

• Intelligence tested using western tests results in lower scores in Aboriginal children
• Piagetian tasks (relies on western schooling for "normal" results

Comparing Intelligences

• Use twin and adoption studies
• Compare the influence of nature vs nurture

Twin Study

• Identical - developed from the same egg, identical genes
• Fraternal - Develop from 2 separate eggs, no more genetically alike than siblings

Scarr ( 1992)

• Heredity plays a role in extraversion/introversion
• Bigger role played by genetics in determining intelligence

Issues with twin studies

• Naturalistic studies do not control for the environment
• Cannot ethically split twins up

Bouchard (1990)

• Study of twins reared together, and apart.
• Tested on ability, personality, leisure time and interests

Bouchard (1990)

• Identical twins reared apart showed similarities and IQ's were similar
• Twins reared together had the most similar IQ

Bouchard (1990)

• IQ of fraternal twins showed the least similarity
• Indicating genetics plays a strong role in IQ