Which of the following observations provides the best evidence that intelligence test scores are influenced by environment?

A. Identical twins raised apart are less similar in their intelligence scores than identical twins raised together.

B. The intelligence scores of children are positively correlated with those of their parents.

C. Identical twins are more similar in their intelligence scores than are fraternal twins.

D. The intelligence scores of siblings raised together are positively correlated.

Answer: D. The intelligence scores of siblings raised together are positively correlated.

Explanation: The dependency of intelligence score on the environment is best highlighted by the scenario which shows positive correlation between the intelligence scores of siblings raised together. The positive corration exhibited by the siblings could best be attributed to the fact that they were raised together, that is environmental factor. Because sibling would likely possess different genetic characteristic. Therefore, environmental impact could have played a role in the positive correlation observed in their intelligence.

A. Identical twins raised apart are less similar in their intelligence scores than identical twins raised together.

Explanation:

To determine if intelligence test scores are influenced by environment or not, the most telling evident from the available options is that identical twins raised apart are less similar in their intelligence scores than identical twins raised together.

This shows that despite their keen close similarities in their DNA, separating identical twins in different environment shows less similarities in their intelligence test scores compared to identical twins raised together.