I appreciate the thoughtful response, and your self-awareness to consider the possibility that your perspective may not be other guys'. I guess I'm interested in your definition of "hurt." Do you just mean physically injured? Or do you also mean emotional duress, nervous system panic and general frantic duress?
The interesting thing about siblings is that older sister/younger brother is the most common scenario for the female to have the size and weight advantage, and at that age, since there's not a lot of tying up going on, older child sitting on younger child is the most common torture scenario. In those cases, I think there's a gender sadism tie. Just my two cents.
Physical injury would obviously be on the list, but I also would not want to really scare someone. There's a difference between the exhilaration/fear of a coming tickling and real fear of being hurt.
As for siblings, just yesterday I saw two brothers about 4 and 1 1/2. The older one was holding a chip bag out of reach of the younger one while he cried. That's the kind of cruelty that siblings commonly do to each other but I rarely see occur between adults. I see that as more indicative of sibling relationships than gender differences.