        The single advantage that an anthropologist had was that he was dealing with humans.  While cultures differed, basic biology did not.  There had been a study years ago showing that different cultures correctly identified facial expressions—humans were hard-wired to know these things.  Any anthropologist could be sure that the culture he was studying held things with their hands—be they weapons or toys—walked upright, used audible language, and had a biologically programmed range of facial expressions.  All of that was completely out the window with an alien race.  He didn’t know if their visual range was the same as his, if they had a mental communication aspect, how they would signal peaceful intentions, or anything at all, really.  In fact, the only conclusion he could come up with was that they were not overtly hostile, since he was still alive.