The suicide bombings in Israel drastically decreased after the construction of the wall to keep Palestinians out.
That's one of those "uncomfortable but true" things that sometimes surfaces here (and threads get dedicated to explore): segregating walls do work.
It's at least, some evidence in that direction.
There's a lot of background mess in our mental pictures of the world. We try and be accurate on important issues, but a whole lot of the less important stuff we pick up from the media, the movies, and random impressions. And once these impressions are in our mental pictures, they just don't go away - until we find a fact that causes us to say "huh", and reassess.
Here are three facts that have caused that "huh" in me, recently, and completely rearranged minor parts of my mental map. I'm sharing them here, because that experience is a valuable one.