Match the types of studies with their findings on the correlation of intelligence scores:

1. Studies on twins reared together

2. Studies on identical twins reared in different environments

3. Studies on fraternal twins reared together

4. Studies on siblings reared apart

Options:

a) Correlation of approximately 0.90

b) Correlation of approximately 0.72

c) Correlation of approximately 0.60

d) Correlation of approximately 0.25

1-a, 2-b, 3-c, 4-d

The intelligence of identical twins reared together correlate almost 0.90. Twins separated early in childhood also show considerable similarity in their intellectual, personality and behavioural characteristics. The intelligence of identical twins reared in different environments correlate 0.72, those of fraternal twins reared together correlate almost 0.60, and those of brothers and sisters reared together correlate about 0.50, while siblings reared apart correlate about 0.25.