Sarah Kliff, at The Washington Post's Wonkblog writes:

To test out this theory, a team of psychologists asked study participants how they felt about a number of mundane and unrelated subjects that included (but was not limited to) architecture, health care, crossword puzzles, taxidermy and Japan. They wanted to figure out if people tended to like or dislike things in general. This was dubbed the individual’s dispositional attitude or, more simply put, checked for whether they were a hater who pretty much hates on everything that comes across their path. Haters are gonna hate.