We now have some data to back up the assumption that you probably already held. Your politically-charged Facebook posts, no matter how impassioned and well-reasoned, are highly unlikely to make a dent in the opinions already held by those who encounter them. But all is not lost. While you might not change your friends’ minds when it comes to politics, you’re almost certainly changing the way they feel about your friendship. (Related: No one is buying the message implied by all those happy family photos you share either.)