Geoffrey Miller, in Spent, documents research into five key personality traits, and concludes that, together with General Intelligence (or IQ), they give us pretty much all we need to know about the inner life of the people we meet. The traits are openness, conscientiousness, agreeability, stability and extroversion. Broadly speaking, populations are distributed in a bell-curve across every trait, and also across IQ. There are few correlations between trait scores, although openness correlates fairly positively with IQ.
Miller suggests IQ is a measure of the healthy functioning of our nervous system, and the personality traits reflect survival and reproduction strategies adopted by our earliest ancestors. Daniel Nettle, in Personality, suggests that openness is a measure of the breadth of connections we make amongst concepts and sensory stimuli. Although there is no moral value attached either to high or low scores in any trait, different communities have favoured traits differently at different times.
Openness carries with it the benefits of creativity, but the risks of psychosis. Nettle argues that openness evolved as the ability to manipulate symbols became increasingly valuable in early human communities. Miller wonders whether displays of extreme openness amongst the young reflect a strategy for demonstrating the essential soundness of their minds.
Openness is linked to artistic creativity, as well as receptivity to unusual experiences, and as such, one might hypothesize, is important to any consideration of spirituality and religion, though a high score would not predict religiosity, which has frequently a conservative bias.
But David Lewis-Williams and David Pearce, in Inside The Neolithic Mind, offer an alternative measure by which the religious content of a community might be explained. They locate the source of religious imagery in experiences of altered states of consciousness. Our minds function across a spectrum of consciousness, from attentiveness to waking reality, through periods of reflectivity, to daydreaming, hypnagogic states, and finally, in sleep, our normal dreamlife. The modern west, they suggest, values the wide awake, rational state, where earlier cultures favoured the various dream states. Therefore, earlier cultures developed concepts of dream wisdom and spiritual realms, which we abandon (perhaps legitimately) for logic and empiricism.
It is certainly very pleasing to correlate religious concepts of the immanence and transcendance of spiritual powers with, respectively, attentiveness to the details of reality, and dreaming swoons. It is also intriguing to ask whether measures of openness and of consciousness correlate. If they do, one might ask whether they are interdependent, or in fact facets of a single trait. If they don't, it might be fair to ask that consciousness be accorded value as a mental trait in its own right.
Perhaps the consciousness spectrum will be found to equate to IQ, instead, except that high alertness might exist in dream states as well as maths tests, but some might prefer to operate in the former, whilst others are predisposed to the latter. If you choose one rather than the other strategy for obtaining survival tips, this may fairly be described as an aspect of your personality, rather than a measure, like IQ, of general health. In any case, whatever the analysis, one might expect preferences to be distributed in a bell-curve across the human population, in much the same way as other traits.