In England, they're sometimes reburried a few years after the excavation. This is, on a humanitarian level, a good thing. I also hate to see the dead (especially from cultures like those of the early middle ages which seem to have believed that a person's final resting place was connected to their experience of continuing existance after death) taken from their places and stored in a museum warehouse, university cupboard, or excavator's shed.

But it can create problems for archaeologists when the human remains are reburied too soon after excavation. A friend is researching early Anglo-Saxon demographics, and suspects that many of the age estimates for adult skeletons are too young. There are new methods being tested for measuring the age of very old persons (60-70 years old), but they require reexamining the bones. But he can't reassess the skeletal material in many cases because it has been reburied. Similarly, my own research examines the relationship between biological sex and gendered grave goods (were women ever buried with weapons?), but some of the skeletons which it might be helpful to reexamine are now back in the ground and out of reach.

So there's a difficult balancing act between respecting the dead and gaining the knowledge we need. We've already made a decision, when we excavate, to disturb the dead (often, it should be said, because the cemetery is scheduled for development, or being looted by metal detectorists - few archaeologists have the budget to seek out and excavate cemeteries that are not at risk these days, in England at least), so we need to find a balance between respecting the dead and getting the most out of our evidence.

This issue was debated publicly in England a few years ago; you can read more if you search for news stories about the controversy.

I'll elaborate on Native American Graves Protection and Repatriation Act (NAGPRA) a bit, since it is the leading law governing native remains in the US, and because a lot of people tend to miss the nuances of the statute. The basic gist of the act is that native remains should be returned to the tribe most closely associated with the remains, but that is deceptively simple.

First, NAGPRA does not apply to all native remains. NAGPRA only applies in two situations: when remains are found on federally owned land, or when the remains are in the possession of a "museum" which receives federal funds ("museum" is defined very broadly to include just about any institution, including schools). NAGPRA does not apply to remains found on private or state owned lands even if the project that uncovers the remains receives federal funding (this is distinct from other statutes like NEPA). See: Castro Romero v. Becken, 256 F.3d 349 (5th Cir. 2001)

Further, NAGPRA does not require repatriation of all native remains even if the above elements are all satisfied. Most importantly, the remains must bear "some relationship" to presently existing tribes. See: Bonnichsen v. United States, 367 F.3d 864 (9th Cir. 2004) (aka the Kennewick Man case). Essentially, if the remains are so old that they can't be conclusively linked to existing tribes, they may not need to be repatriated. This is a contentious field of litigation surrounding NAGPRA and is not totally settled at this point.

The Kennewick controversy is by far the highest profile NAGPRA battle, and worth further research if you're truly interested in this issue. The TL;DR is human remains were found on land owned by the Army Corps of Engineers (COE), the remains appeared to be very old and featured traits not common amongst typical native remains. Because of these factors, scientists wished to study the remains. Tribes in the area, however, made NAGPRA requests to have the remains repatriated immediately, which the Army COE attempted to comply with, which would have meant the remains would be buried in a secret location, lost forever. The scientists sued, claiming that the remains were 10-12,000 years old, and the tribes in the area had only been there for a few hundred years and therefore could not have any connection to the remains, and a protracted court battle followed. As mentioned above, the court ruled that within the meaning of the NAGPRA statute, there must be a connection between the remains and currently existing tribes.

In Northwest continental Europe, human remains are simply treated like any other archaeological artefact. Put on display, stored in an archive, the same you would do with animal bones or ceramics. This applies even to medieval cemeteries. I have not heard of any cases of reburial where I work.

I am also not entirely sure whether this is an ethically good practice, but I have also not heard any complaints by members of the public about it.

This does not mean human remains are not treated with respect, though this standard does need to be actively enforced. I heard of one case in the Netherlands where where students were playing music while digging an actively used cemetery. I doubt the professional archaeological attitude is any different from anyone else working with human remains, however, such as morticians. Their public and private/professional attitudes are also quite different.

In the western US Native American groups tend to be pretty sensitive about exhumation of their ancestors. In California,Oregon and Washington the common practice is to coordinate with the "most likely descendents" and follow their requests. This usually means reinternment at an agreed location. The sensitivity of natives in Northern California is well founded. In the 1950s, UC Berkeley students were excavating sites in the Yurok territory under the leadership of Robert Heizer. Despite their assurances that they would not do so, they removed the skeletal remains of people closely related to living tribal members. In response to university led excavations, and rampant pot hunting of traditional Wiyot and other sites (one collector excavated over 400 burials), the native groups created the Northwest Indian Cemetery protective Assn. to lobby lawmakers to protect sites and do project reviews. An excellent resource on this history is found in "Grave Matters: Excavating California's Buried Past ", by Tony Platt.

The way the remains are treated varies widely depending on the local laws and the age of the remains. Remains from the relatively recently deceased obviously may have living relatives that could have a say in the way in which the remains are treated. In the US, it is additionally complicated by whether the remains are from an indigenous inhabitant or not. Sets of laws such as NAGPRA often dictate that the descendants have the say in what happens. This can lead to some funny situations where the tribe or group with custody over the remains may not even be related (genetically) to the remains, but their oral traditions may claim that they are the descendants. At any rate, a group with custody may refuse analysis of the remains and request reburial.

That being said, I have seen many, many bones in boxes on storage room shelves. Many sets of human remains are not reburied; instead, they are cataloged for possible future analysis and preservation. This can be a touchy subject depending on your personal views. All the professional archaeologists I have known and worked with show a great deal of respect for the remains. We are well aware that they were living people just like us and deserve respect. It's the least we can do for digging them up.

It is also important to note that we generally can't know what the person would have wanted done with their remains in a situation like an excavation. The best we can do as archaeologists is handle the remains with respect, preserve them, and do our best to tell their story.

It depends on location, but in the US, where I am from, it depends on who owns the land and who owns it. Where I am currently at, if we find Native American Remains, we usually need to contact a tribe in the state who's ancestors lived in the region, which is easier here as that is pretty simple based on time period. They usually can help identify if they are related, and help to decide what to do with the remains. Now, if these remains are found on a private site, and are in no danger, they will usually be left, and any private land cannot be forced to let us exhume them. There are laws regarding what the owner can do the grave, drawing a blank on those laws right now, but we as archaeologists cannot force anything to happen.

There are laws in place the protect remains, and procedure that occurs when you find them. I am sorry for not sourcing direct laws, I am about to head to class so I have no time for that, but for the most part, unless you are looking for human remains in the US, you probably don't want to find any, as it just ramps up the complexity involved with working the site.