>>17834840 (OP)This was proven already incorrect
This graph is less about "intelligence between faith" but intelligence between high and low median income
Education increases your IQ
Rich people are more likely to get education
Rich people are more likely to be atheist.
Similarly, Jewish communities have a culture that focuses on monetary income, which also increases their educational attainment.
If you divide this based on income, the Christians actually come out on top.
As such, the better question is
Why are the people most blessed by the God the ones who reject him the most