Updated the FAQ

[Loser]

Originally posted by Slick:
7.2.9 Captured population (by any means) loses all of its racial attributes and is identical to yours except they retain their atmosphere breathing so can be used to populate your colonies appropriately AND they slowly get unhappy over time so you need to account for that so they don’t riot (riot police, upc, etc.).The positive happiness effect of 10 troops of any type will exactly cancel out the negative happiness of having alien population on a planet.

I believe they also get angrier while you are at war with their mother-empire.

But I am a slacker, and have not checked the FAQ to see if that is also covered in that specific block. I'll apologize for the slack, but I won't promise a change.