Greys

Greys don't have feelings. And that's why they sometimes ride rough-shod over ours. They don't intend to be mean; they just don't understand why we should object to being hauled out of bed in the middle of the night and onto ships to be experimented on when the outcome is mutually beneficial. "Look, it's for the common good; why would you have problems with that? Besides, when you were out of the body, before this particular incarnation, you agreed to join the programme. I know you don't remember doing so, but you did, so please be reasonable! Oh, I see, it hurts your feelings. How fascinating. Yes, please explain. We're interested. In fact more than interested. We'd love to have feelings too..."

And that, actually, is what it's all about. As they've explained to contactees, they, the Greys, were once a warlike race that came close to self-annihilation. They thought they could curb their aggression by modifying their genes to get rid of all their emotions- and it worked; only along with aggression they also got rid of sexual attraction- and now they're a dying race because they can no longer breed. They want their emotions back- well some of them anyway, and have been abducting humans in order to identify and harvest the genes that they now lack- with the aim of creating a hybrid species- part human, part Grey- spiritually and intellectually advanced- as the Greys are- but with with the ability to feel positive emotions. And it seems they may have succeeded. Contactees have been introduced to people they've been told are their sons and daughters- small people, pale skinned, with big heads, peaky faces, huge eyes and wispy fair hair...

There are, to be clear, several ET species who get lumped together as "Greys". The ones who concern us here are the small Greys- who apparently come from the binary star system we know as Zeta Reticuli.