The median income of high school is 60% of college graduates. Do you believe going to college is the reason or is it IQ differences and other factors?

The median income of high school is 60% of college graduates. Do you believe going to college is the reason or is it IQ differences and other factors?
Updates
25 d
I am certain if you compare the median incomes of people with IQs of 120 and higher that are dependable and motivated to succeed with the median incomes of people with IQs of100 and below, many of whom are neither dependable nor motivated to succeed, you would get very similar results. That is because college graduates have IQs averaging, 120+, they are dependable or else they skip too many classes, and the must be motivated or else, since college is hard, they would not graduate.
The median income of high school is 60% of college graduates. Do you believe going to college is the reason or is it IQ differences and other factors?
Post Opinion