A Type D personality is distressed, Type D's have a negative outlook towards life and are pessimistic. A small event that is not even noticed by type B can ruin type D's day. Type D personalities are more subject to depression than other personality types.
For most of human history, horses were seen as prey to be hunted for sustenance. During the late Pleistocene, around 55,000 years ago, Neanderthals scavenged off of horse carcasses and made occasional kills of their own.
They were definitely not our food. But We HAVE Eaten It. That is not to say that Americans have never eaten horse in times of desperation. There's ample evidence that when food ran out during the Civil War and even World War II, eating horse meat became a common (and cheap) solution.