>>12037269>explain why the greys started appeared when people who saw Spielberg's movie as kids became adults.They didn't.
Greys were concocted out of the 1950's idea of "little green men" who supposedly lived on Mars.
The entire "Mars Attacks" bubble gum card series were based on them.
When a distraction was necessary, the alphabet boys simply used the concept of little green men, turned them gray, but kept the other physical aspects...they were small, had huge brains, smaller vestigial features (ears, noses, etc.). Not very imaginative, but easy enough to fake, using apes.
The entire "little green men" idea was simply the idea of what people would "evolve" into, if the theory of humans evolving from an apelike creature was true.
We are weaker than apes, have almost no canine teeth, almost no body hair compared to them, but bigger brains...we are to "little green men" what apes are to us.