So if a mass hallucination is a group of people experiencing some type of sensory malfunction and they all agree to a consensus interpretation, how do we know that the day to day reality we experience isn’t some kind of hallucination as well? How many people does it take to agree on an interpretation of a scenario before it officially becomes “reality?”
We all only have the information our senses provide us to try and piece together some version of reality to place ourselves in to exist. For the most part, we agree on what something looks, or sounds, or feels like; but to what degree and the significance of that information can vary quite a bit. Our beliefs and expectations can make a huge difference in how that information is processed and what it means.
It would be easy to dismiss a story of a UFO sighting if only one or two people in a large group of individuals present where witness, while 20 others saw nothing unusual. But in most cases involving large groups of people present during a sighting, everyone present sees something. The may not always agree on what exactly it was, but the sensory information reported is consistent. So if the group all decides the consensus perception was flying lights in the sky, doesn’t that make it “reality?” Regardless of what others say after the fact, the truth lies with the beholder. Telling someone the UFO they saw could not be real, based solely on the fact that you have never seen one before is just like telling someone their nose could not possibly itch, because your nose doesn’t itch right now.
The Burning Satyr 