Remember the whiny, insecure kid in nursery school, the one who always thought everyone was out to get him, and was always running to the teacher with complaints? Chances are he grew up to be a conservative.
While the study is kind of funny, the science behind it looks like crap. A 7% variance might be strong in the soft sciences, but it still should be looked at with heavy skepticism. Second, terms like rigid seem really difficult to quantify in any meaningful way. I am not willing to waver on my disapproval on the use of torture. Does that make me rigid or principled?