In the current era: Intelligence Quotient or IQ is no longer considered as a measure of Intelligence.
IQ is hereditary and an Indoctrinated high IQ individual religious devotee, can be just as hooked and Irrational as any normal to low IQ devotee.
The difference is that high IQ devotees can be more clever in creating their Apologies (Porkies) for their belief system. Thomas Aquinas is an excellent example here, very high IQ, very indoctrinated into belief in Catholic Porkies. He created some quite cleverly obfuscated Porkies.
Where Aquinas failed was on the Rationality front, his apologies were very clever, but when looked at from a logical/rational basis, they were highly Irrational. Thus Aquinas had a very low Rational Quotient (RQ).
Thus Aquinas may have had a high IQ, but he really wasn't that Intelligent, because his ability to think Rationally had been compromised by his delusional world-view. So he was of only average Intelligence, in spite of his high IQ.
On the other hand we have Islamic Fundamentalist leaders that only have an average or even below average IQ, like Ayatollah Ruhollah Khomeini, whose inhuman policies, actions and comments comments and hatred of Salman Rushdie over a simple novel, made Iran appear to be a country full of fundamentalist crackpots and himself a Narcissistic Megalomaniac idiot.
Yes, he may have had a reasonable IQ, but it was completely obliterated by his extreme Fundamentalism.
Meaning that he really was not as Intelligent as your average secular or non-committal janitor, which may have even been a better choice for leading Iran.
But, religious Fundamentalists are attracted to extreme religious Fundamentalists, as they are all seek more low RQ, or Irrational spiritual goals. So it doesn't pay to be rational, because rationality to a Fundamentalist is ugly and the enemy.
Rational or scientific fundamentalists are actually the other side of the extreme, many of them have an extremely high rationality which drives them to seeking the extremes in scientific concepts and knowledge. Which is different to crackpot science fundamentalism like Michael Behe and Rupert Sheldrake with their stupid "Irreducible Complexity" and "Morphonic Resonance" concepts, which really are not rational. Such junk science fundamentalists are really no better than Religious Fundamentalists, because their pseudo-science is based on Superstition, just like religion so they are really Superstition Fundamentalists, like Sam Parnia with his "Near Death Experiences" Fundamentalism, that is equally as ridiculous as the other two's misconceptions of reality.
Hopefully the world will wake up and find some form of Rationality testing to ensure that Religious Fundamentalist crackpots (Low or No Rationality), never make leadership again.
Because even in industry, they have found that people with a low Rationality (RQ level) have a tendency to not think problems through rationally and jump to stupid irrational decisions or concepts.
Thus low RQ individuals tend to make more and bigger errors, just like the many that Khomeini made.
This is why industries are devising RQ testing to ensure only the most intelligent, less error prone workers are chosen. Those that fail, can go back to school and improve their RQ.
Unlike IQ, RQ is not inherited, it is improved through good education practices.
Improving the education for all children, will raise the average RQ of a nation.
There is absolutely no reason to allow Irrational people into Leadership.
People with deeply held Irrational concepts like Mitt Romney, are signs of an Irrational (Low RQ) individual, US is very lucky it didn't put such a person into the highest office.
All leaders should be tested for Rationality, if they are not at least 90% rational, they have no business leading a nation.
If a nation can increase the average Rationality (RQ) of it's citizens, we may eventually be able to wipe out Extreme Religious/Superstitious Fundamentalism, or at least confine them to the Lunatic Asylums where they surely belong.
They certainly don't belong in Politics or controlling a Nation.
History has proven how seriously bad it is for a nation to have such leaders.
Citizens rights suffer, citizens are divided, poverty and oppression escalates, Irrational conflicts and wars are initiated. The nation becomes as Irrational as it's leadership.
Because Superstitious Fundamentalism Destroys Intelligence!