It is plausible that an existing species of dolphin or whale possesses symbolic language and oral culture at least on par with that of neolithic-era humanity. (75%)
Is "it is plausible" part of the statement to which you give 75% credence, or is it another way of putting said credence?
Because cetacean-language is more than 75% likely to be plausible but I think less than 75% likely to be true.
I was very interested in the discussions and opinions that grew out of the last time this was played, but find digging through 800+ comments for a new game to start on the same thread annoying. I also don't want this game ruined by a potential sock puppet (whom ever it may be). So here's a non-sockpuppetiered Irrationality Game, if there's still interest. If there isn't, downvote to oblivion!
The original rules:
Enjoy!