From the abstract: "Adult cats from two populations (pet and shelter) were presented with three stimuli within each of the following four categories: human soci

From the abstract: "Adult cats from two populations (pet and shelter) were presented with three stimuli within each of the following four categories: human social interaction, food, toy, and scent." Cat on cat social interaction wasn't in the variables. So, the cats in the study highly desired social interaction, not necessarily from humans. If they had included falling anvils, I would bet on the cats eschewing that variable.