Even then he can become a Muslim apologetic so would that make him a idiot?
And trust me becoming a apologetic requires a lot of study in the areas like philosophy, physics, metaphysics and etc.
I wouldn't say that your spawn point decides all the things you can learn neither that you cannot believe in other things.
Not only that but being religious doesn't mean you are "low IQ" many historians and apologetics with high levels of intelligence and with a vast knowledge in philosophy came to the conclusion that God exists.
Your generalization makes no sense.
But if you wanna say that the average religious person is dumb then I'll have to agree but with some nuances.
Being average will probably indicate you have average to low IQ,so that person being "dumb" is kinda of expected.
BUT this also happens with atheists.
Many atheists are average to low IQ, which means they also wouldn't be able to think that deeply about their stances.
What I'm saying is: There is no dumbest.
Both atheism and Theology have extremely good points.
And both atheism and Theology have extremely high IQ individuals and also the other way around (because most people on both are average to low IQ).
Ayo don't call me honey cuz that's sus