The first burials might be opportunistic, there is already a hollow in the ground and some loose dirt with which to fill it. It may have been carried out repeatedly and over very long periods of time (hundreds of thousands of years) concurrently with other means of disposing of body in a manner conducive to safety of the band, without there necessarily being particular ritualistic significance being attached to the practice.
However, I think the manner of the development in perception and cognition do not perfectly correspond to external pressures. Much of the development is shaped and constrained by prior existence of other perceptual and cognitive mechanism in the brain that can be co-opted and combined to adequately serve some new function or role. I suspect the perceptual mechanism for evaluating another member of the group, band, or clan always involved one set of mechanisms that evaluate physical behavior, and another for assessing intentions and emotions. These probably evolved at widely different times in our evolutionary history, and involve totally different mechanisms. Hence the perception of physical behavior have a different feel from perception of intent and emotion. So there was always some underlying neurological basis for not totally and completely associating the person defined by emotion and intent with the person defined by form and flesh and blood. So my guess is the earliest ancestors of notion of afterlife and soul long predated the first specifically ritualistic burial.
However, I think the manner of the development in perception and cognition do not perfectly correspond to external pressures. Much of the development is shaped and constrained by prior existence of other perceptual and cognitive mechanism in the brain that can be co-opted and combined to adequately serve some new function or role. I suspect the perceptual mechanism for evaluating another member of the group, band, or clan always involved one set of mechanisms that evaluate physical behavior, and another for assessing intentions and emotions. These probably evolved at widely different times in our evolutionary history, and involve totally different mechanisms. Hence the perception of physical behavior have a different feel from perception of intent and emotion. So there was always some underlying neurological basis for not totally and completely associating the person defined by emotion and intent with the person defined by form and flesh and blood. So my guess is the earliest ancestors of notion of afterlife and soul long predated the first specifically ritualistic burial.
