The group doesn't force you to lie. It's a matter of emphasis. There are things you naturallly notice and think about that the group doesn't want you to talk about. Getting sickly silence when you speak is no fun, so you don't talk in that direction. Not talking is easier if you don't notice and don't think in that direction. There are also some mild feelings you naturally have that the group likes. So you intensify your expression of these emotions which intensifies your inner experience of them. The applause that follows expressing these popular emotions helps fill the space left by the things you don't notice anymore. Over time, your mind is custom designed, but not for you.