Question

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 to about:

• A. 0.72
• B. 0.60
• C. 0.50
• D. 0.25

Hint:

Identical twins reared apart: about 0.72; reared together: about 0.86.

Answer 1

The Correct Option is A

Step 1: Understand the question:
The question asks for the correlation between the intelligence scores of identical twins who grew up in different environments. This is a classic finding used to show the role of heredity.

Step 2: Recall the research data:
Studies of identical twins raised together give a correlation close to 0.86. When identical twins are raised apart, the correlation is about 0.72. This is still high, so heredity has a strong effect on intelligence.

Step 3: Check option 1 (0.72):
This matches the reported value for identical twins reared apart. So option 1 is correct.

Step 4: Check option 2 (0.60):
A correlation of 0.60 is closer to the value for fraternal twins reared together (about 0.60). So option 2 is wrong.

Step 5: Check option 3 (0.50):
A value of 0.50 is close to the figure for siblings reared together. So option 3 is wrong.

Step 6: Check option 4 (0.25):
A value of 0.25 is close to what is found for unrelated children reared together. So option 4 is wrong.

Final Answer:
The correlation for identical twins reared apart is about 0.72. \[ \boxed{0.72} \]