I don't think class can really be divided into neat categories, but I think it nonetheless exists, at least insofar as people of common socio-economic status tend to group with one another. You can see this in how people talk on a daily basis - go analyze the voice and behavioral patterns of someone talking to their friend versus someone they perceive to be higher up in the social hierarchy, like a celebrity, and it is obvious something is going on inside the brain.
Man is a social animal, and the basis of our existence is our senses. It is no coincidence that those with the most power are also those with the ability to best satisfy their sensory needs, through material possession, or the fulfillment of a fetish of one kind or another (i.e.desire for power). The hierarchy exists, class exists, but it's analysis has been poor so far. Science will help with that, as you suggest.