This is perhaps the most difficult question of all. We have no doubt that Upper Paleolithic people had their own forms of religion...but to what degree did it involve visual representations? If Lewis-Williams, whose work we discussed above, is correct in thinking that Lascaux was painted/engraved while people were in an altered state of consciousness, the idea that this cave was painted/experienced in a religious context gains support. Attempts to attain trance and seek visions are very much a part of the religions of many cultures studied by sociocultural anthropologists.
There are other clues as well. For example, at the 12,000 year old German site of Gonnersdorf, Bosinski (1984) excavated hundreds of engraved stone slabs that had served as floor pavements for at least three dwellings. Each of the dwelling floors showed the dominance of a different animal species in its engravings. Moreover, almost all of the slabs had the engraved face down, invisible to the occupants. It is easy to hypothesize (much harder to test) that the engraved images were intended to have some sort of power other than that of art objects. However, the association of different animals with different dwellings is also suggestive of a link between certain animals and certain social groups. There is of course every probability that visual representations operated in the social and religious domains at one and the same time.