Spirituality, as a form of knowledge-seeking, must be pursuing truth, otherwise it would be pursuing falseness. Intellectualism also pursues truth. So there appears to be an equivalency here of intellectualism and spirituality based on the pursuit of truth about the world.

Even though spirituality is often normative in nature - "you should do this or that to be happy and fulfilled" - it still seems to make definitive claims about human origins, qualities, and actions. Personally, I think intellectualism and spirituality largely overlap as spirituality is more or less making inferences about spiritual and possibly immaterial aspects of our universe based on what we currently know about the world and ourselves.

There is definitely more to the story of existence than what science can currently explain, so I think spirituality plays a very important role about theorizing about future discoveries. We are so often taught intellectual pursuits as if we have mastered them all, which is far from the truth. Greek spirituality had Poseidon controlling the tides, but now we know the moon is largely responsible for this.

Ancient spirituality helped humans of the time explain something they did not understand, which is an important quality of spirituality and religion. Now the question is where we use spirituality today to explain what we don't understand and how we will come to get closer to the truth.

Maybe some Nexians have spiritual ideas about the entities we encounter on DMT trips; I sure do. I think these theories, while spiritual, are part of the intellectual process of hypothesizing and framing possible explanations. For these reasons, I would not be surprised at a strong correlation (if not causation) between the concepts.