1. Pensive , meditative , reflective suggest quiet modes of apparent or real thought. Pensive , the weakest of the three, suggests dreaminess or wistfulness, and may involve little or no thought to any purpose: a pensive, faraway look. Meditative involves thinking of certain facts or phenomena, perhaps in the religious sense of “contemplation,” without necessarily having a goal of complete understanding or of action: meditative but unjudicial. Reflective has a strong implication of orderly, perhaps analytic, processes of thought, usually with a definite goal of understanding: a careful and reflective critic.

Did you mean pervasiveness?