If we were headed for some type of armageddon and the think tank knew it, Do you think they would tell us?

Most likely not.

If they told us, there would be a great panic, and chaos would erupt. A scared person isn't reasonable - imagine what 6 billion scared people would be like.

Personally, I'd rather not know. This way, I could live peacefully for a while until the end.

I guess it would depend on which think tank you're referring to. an MIT think tank, probably. A Pentagon think tank, doubtful

Probably not, might as well let people go about their daily lives as if nothing were to happen.