Since the idea that animals are just little biological machines, living unemotional lives run by instinct and base condition alone, has never really sat well with me—I've always sensed there was more going on inside their heads than this—this next one really got my attention.
Researchers from the University of Bristol have shown via experiment that dogs can be essentially optimistic or pessimistic by nature. As The Economic Times glibly describes it, there are dogs that see the glass (uh, bowl) half empty and those which see it half full.
The experiment to demonstrate this consisted of training dogs at two UK rehousing centers that when a bowl was placed in one location in the room it contained food and when placed in another location it'd be empty. After which, the food bowl was placed in various locations in between the two.
The researchers found that some dogs, classed as 'optimistic', ran quickly to the middle locations, expecting food to be there, expecting a reward. Other dogs were, shall we say, less enthusiastic.
Extrapolating, those that were optimistic in nature were less likely to be anxious when left alone than dogs with a more pessimistic nature. The researchers say that about half the dogs in the UK at some point exhibit "separation-related behaviors—toileting, barking and destroying objects around the home—when they're apart from their owners. Our study suggests that dogs showing these types of behavior also appear to make more pessimistic judgement generally."
Perhaps it's being too generous to ascribe optimism and pessimism to these behaviors. After all, we can't fully know what's going on with these dogs minds, any more than we can directly know the same for humans. But it is fascinating to me nevertheless to learn that, as with people, there well may underlying emotional states—not just conditioning—influencing the behavior of dogs.
After all, this is what most dog owners (and pet owners more broadly) intuitively know anyway. But now you can point to a study demonstrating this.