Yes that was my point...it's an evolutionary feature of humanity. I also consider the things you just mentioned to be down to our natural ability to empathise with those closest to us. The most impressive examples are twins..some twins are seemingly able to hold whole conversations without speaking. I have had the same shared thought effect with my sister, however it is logical to say that people who are exposed to the same stimuli will more often deliver a similair responce. It is not a psychic link I believe but the effect of developing similair patterns of thought to those people you know very well.

Or to simplify for Red Meat who hates long answeres:
If you put the same Sh*t in two different bins, pretty much the same sh*t will come out.