Which of the following most closely approximates the correlation a researcher might find between the intelligence test scores and the household incomes of a sample of American adults?

A) .91
B) .36
C) -.41
D) .05

There is a positive correlation between intelligence and income, but it is not perfect (i.e. not close to 1). A correlation of .36 would indicate a moderate positive correlation, suggesting that as intelligence test scores increase, so does household income, but there is still variability in the relationship. Choices A and D are too high and suggest a near perfect positive or positive correlation, respectively. Choice C is negative, which suggests intelligence test scores and household incomes are inversely related, which is not supported by research.