Similarly, the descriptions given by people who clain to have been abducted and worked upon by aliens in the past century are amazingly similar to the descriptions of being visited by an incubus or succubus in the Middle Ages.
There are some notable similarities to descriptions of visiting Fairyland too - elfin figures appear out of nowhere and cast a spell so that a human becomes unable to resist, then the human is taken to a fantastical place... and often, when they return the think they were only gone for a few hours but in fact years have passed.
Actually the UFO's at the turn of the century were like the Goodyear blimp and they flew like them also. Next we had long cylinder rockets and air ships. These improved in design and got faster. Finally we has flying discs of various types and shapes that could do almost anything in speed and maneuvers. This tells me that UFO's evolved as the human mind evolved. The occupants evolved in much the same way. Starting out as human they have now went into the grays and so many other types it isn't funny. I highly suspect that science fiction books and movies have added to this phenomena.
Yes - interesting how UFOs seem to have whatever sort of technology is currently cutting-edge on Earth, isn't it? Personally, I think that's because the people who see them are either mistaken about what they've really seen, imagined what they think they saw or are lying, though.