Some of it is certainly cultural we see images of skeletons in so much of our literature, horror movies etcetera. However, and this is conjecture, I suspect there is actually an evolutionary component to it as well. read more
For example there might be a large predator nearby. So the site of a skeleton becomes a proxy for other threats. And there may be an important survival benefit to paying attention to those types of threats. I don't know if any studies have actually been done on this whether with humans or animals. read more