The written word is MUCH newer, and hasn't resulted in evolutionary adaptations like spoken words have. When you read something, the information enters your brain through different pathways. And these don't include our spoken word filters.
The information IS filtered, AFTER the fact. Usually immediately after, but AFTER its already "in" your head. Not before it can get in in the first place, as when we hear information.
Check out Cognitive Linguistics for your self. Frank Luntz's PR companies' slogan is "Its not what you say, its what they hear." He gave us the term "death tax". Cognitive linguistics is a real science that has been advancing by leaps and bounds since realtime brain activity scans became available.
Make no mistake: what others know about how your brain works, that you don't, can be and is being used against you by those who stand to gain by influencing your feelings and beliefs.
You can't swing a cat in political discourse and not find applications of this science. ALL political messages are constructed using it.