Is accepting new survivors mandatory?
Outsiders cards are just like any other card when you are searching.  You can absolutely make noise and choose not to keep them.

Once you do keep them, they go in your hand and don't take effect until you decide to play them.  You might want to hold a card that will add too many helpless survivors if you are short on food this turn.  Or maybe you're the betrayer and you want to surprise everyone by playing a bunch of helpless survivors at an inopportune moment.

Outsiders can even be requested if someone else decides that they really need another character.

Here's a post from one of the game's designers on BGG confirming these rulings.


  yes, you add them to your hand like any other card, and can play it,
  request them, and give them to a request.