One should see correctly what IQ is. It measures response time, searching for patterns, analytical processes and knowledge. People who have high IQ's are therefore more suitable for leadership positions since they on average make better decisions here in the material world.
This does however not make a person wiser, happier or more sensitive to the spiritual. The last research I read is that the happiest people are not in the western world at all, but in Afrika (Nigeria if memory serves). So they enjoy their lives more than we do and so I would postulate that despite their lack of IQ they are a lot wiser.
One can adapt to optimize oneself in the material world or to optimize oneself for the spiritual world and optimization in one can be a drawback for the other.
If I would spend my working days reading aura's, praying all will go well and consulting spirit guides instead of resolving arguments, analyzing data and forming strategies, procedures and tactics I'ld soon be out of a job for mismanagement. However if I would deny the existance of the spiritual my life would be lacking an important dimension which gives me contentment, a sense of fullfilment, peace, harmony and purpose.
I think those of high IQ should use their high powers of perception and analysis to find out what they want for themselves and adapt their methodology to the spiritual terrain which is another dimension with other requirements, strategies and tactics than the material.
Spiritual development however can be quite separate and even opposite to organised religion.