David wants to look at genetic influences on IQ,so he administers a battery of tests to Frank and Fred,who are fraternal twins; Sidney and Sheldon,who are identical twins; and Larry and Harry,who are non-twin brothers.David's supervisor asks him to make estimate which set of siblings will most likely have the most similar IQs.What is David's best guess likely to be?
A) Frank and Fred
B) Sidney and Sheldon
C) Larry and Harry
D) As they're all siblings, the correlation should be about the same for all pairs.

Question

Quizplus · Accepted Answer

Since Sidney and Sheldon are identical twins, they share nearly 100% of their genes, while Frank and Fred are only fraternal twins and share about 50% of their genes. Larry and Harry are non-twin siblings and share roughly 50% of their genes as well. Therefore, if genetics play a significant role in IQ, Sidney and Sheldon will have the most similar IQs compared to the other pairs.

David Wants to Look at Genetic Influences on IQ,so He