Arrange the following from the highest to lowest level of correlation in terms of IQ:

(A) The correlation between siblings reared together

(B) The correlation between identical twins reared together

(C) The correlation between siblings reared apart

(D) The correlation between identical twins reared in different environments

(E) The correlation of fraternal twins reared together

Choose the correct answer from the options given below:

The correct answer is (B), (D), (E), (A), (C).

This question asks us to arrange different pairs of individuals based on the correlation of their intelligence quotients (IQ) from the highest level of correlation to the lowest level of correlation. The correlation in IQ is heavily influenced by both genetic similarity (heritability) and environmental factors (whether they are reared together or apart).

Let's analyze the genetic similarity and environmental sharing for each of the given categories:
1. (B) Identical twins reared together: Identical (monozygotic) twins share 100% of their genetic material and, when raised in the same home, also share a common environment. This combination of identical genetics and shared environment yields the highest correlation in IQ, typically around 0.85.
2. (D) Identical twins reared in different environments (reared apart): These twins still share 100% of their genetic makeup, but they grow up in different homes. Despite the different environments, their identical genetics maintain a very high IQ correlation, typically around 0.72 to 0.75, which is higher than any other group except identical twins raised together.
3. (E) Fraternal twins reared together: Fraternal (dizygotic) twins share about 50% of their segregating genes (just like regular siblings) but share the same womb and are raised in the same environment at the exact same time. The shared environment gives them a slightly higher correlation in IQ (typically around 0.60) compared to ordinary siblings of different ages.
4. (A) Siblings reared together: Standard biological siblings share about 50% of their genetic material and grow up in the same household, but they are born at different times. Their IQ correlation is typically around 0.47 to 0.50.
5. (C) Siblings reared apart: Biological siblings who share about 50% of their genetics but are raised in different households lack the shared home environment, resulting in the lowest IQ correlation among these options, typically around 0.24.

Comparing these correlation values, we get the following sequence from highest to lowest:
Identical twins reared together (B) > Identical twins reared apart (D) > Fraternal twins reared together (E) > Siblings reared together (A) > Siblings reared apart (C).

Therefore, the correct arrangement is (B), (D), (E), (A), (C).