evaluating methodology of the biological approach

PARA 1: 

• Assumption of the biological approach- influence of genes on behaviour
• they use twin studies to compare effects of genetics versus environment.
• Bouchard and McGue studied twin. MZ (monozygotic twins) share 100% of their genes and are identical
• for MZ twins they found a mean concordance rate of 86%, this shows a large part of intelligence is inherited. 
• they also studied DZ (DIzygotic) twins= non-identical, sharing 50% of their genes
• they found a mean concordance rate of 60%
• also looked at MZ twins reared apart. found a mean concordance rate of 72%. this continues to show that large part of intelligence is inherited. 

PARA 2: 

• one strength of twin studies is that it since MZ twins share 100% of their genes, they make perfect participants for the study of the effecs of genes on behaviour.
• ANOTHER STRENGTH: within the field of intelligence, e.g. comparisons between MZ twins reared apart and together has allowed psychologists to make sound assumptions about the relative importance of…