Here's one that might be similar to what you're looking for - but much less complex:
Have about 1/4 of your group pulled aside (before the meeting) and instructed that they are aliens but want to mix in. The only thing that sets them apart is that they have difference social skills than humans. See below:
Humans vs. Aliens
Shake Hands = Click Heels together as greeting
Nod for head to mean yes = Click tongue
Yawn when tired = Get up and walk around
Yell when angry = Smile
and so on....
What happens is that the humans and aliens mix together and the humans try to find all the aliens (without knowing the social differences).
It's more of a mixer games I guess, but I thought it might get you started if you wanted to flesh it out some more. Thanks again,