Maybe it is just me, but I do not tend to laugh when someone falls or has mishaps. My first reaction is fear they may have hurt themselves.

I do laugh when I myself fumble, trip, knock against something. Well usually, unless it was particularly painful. Then I swear or cry which may be laughable to me at a later time.

I remember a teenage girl acting out some bit of pageant, tumbled down about 4 stairs at back of church which led to landing then onto cellar. We all gasped and were silent until she climbed up looked over the rail and demanded with silly smile on her face, "Who put those there?"