They say "neighborhood disorder" and a depressed mom or stressed parents are also factors, but just having it on while little kids were around was enough to make them more aggressive when those things were controlled for. The authors say "Further research is essential to determine whether pediatric recommendations concerning TV and children should include limits for general household TV use."
I don't think so. It's not right to say that watching Starsky and Hutch while your toddler is playing with blocks on the floor in front of the TV will cause her to join Hell's Grannies (video; transcript) when she's an old lady, but if I had a toddler again, I think I would have the TV on a lot less than I did when I did.
Of course, since kids vary, and some are too shy, maybe watching a little football with dad will make men out of them. (I think of Beasley's dad giving him football pads for Christmas in Bloom County.)