I think the finding that people commit more acts of cruelty on reality television than in fictional shows is simultaneously questionable and interesting. First, I think it's important to recognize that while more acts of cruelty may be broadcast on reality programs, that's the result of many more hours of filming than are actually shown. The minute-per-minute bad acts in reality television may represent concentrated bad behavior by people who still behave better than the fictional characters dreamed up by writers and producers. Second, television shows are probably relatively evenly balanced between shows that portray real life much more optimistically than it really is and shows that portray it more pessimistically, so the average is the result of shows with wildly different world views.
But I also think the tendency towards cruelty has a lot to do with how we view reality these days, as somehow...deficient in comparison to the rich worlds of entertainment we've created. I think this is where the plague of fake memoirists and heightened so-called reality programs comes from, a sense that our own lives couldn't possibly be as interesting and rich as blockbuster movies or novels, so we have to augment them. It's a bit sad, really. In an age dominated by reality programming, we have less respect for and interest in actual reality than ever.