It's worse then that: What do you think they think you are thinking?

People generally assume purpose, correctly or incorrectly. If you bring up your IQ, your audience is going to ask themselves -why- you are bringing up your IQ. And they're unlikely to find any good reasons, which leave only the bad.

(Not to mention that most people who bring up IQ -are- socially inept, precisely because of social policies against bringing up IQ. It's unfortunately a stable equilibrium. You'd need a popular movement to change the social mores there, and I don't think most people are going to care enough to get involved in it, compared to the other social problems our society faces.)