Engineer jokes abound for a reason. I think we get trained to think in math and look at everything as a problem to be solved. Plus we seem to have a lot of introverts. A lot of the time most people spent practicing social interaction, we spent hanging out in our heads and never finessed the people skill set. Personally, I think we hang our old posters up in academic buildings so we can look at something besides the other people in the hall as we walk by them.
However, yesterday I walked across the engineering quad and was looking at someone who had a sweatshirt I liked. In that awkward moment when he realized I was staring, instead of the standard everyone-looks-away or the territorial stare-down, he just smiled and everyone's day carried on a little more smoothly. Now, to implement a new interaction algorithm!