It is, however, more or less widely accepted now that animals do feel some range of emotions. After all, a fear response is critical for animals to avoid danger. With the exception of primates, animals are widely thought to have only primary emotions- the most common of which are fear, happiness, sadness, and anger (yes, like in Inside Out, except disgust). Some psychologists extend the list of “basic” emotions to surprise and disgust as well. The list of main animal groups in order of biggest to smallest emotional variation are mammals, birds, fish + amphibians + reptiles, and finally insects. It is interesting to note that as the list goes on, the ease of observation for an animal decreases and that there is some ambiguity, such as with reptiles, fish and amphibians, as enough research hasn’t been done yet.
As previously mentioned, complex or secondary emotions (such as jealousy, guilt, pride and contempt) were thought to only occur in primates. It should be pointed out though that this is due to a lack of proof of secondary emotions rather than proof that they do not feel secondary emotions. Dogs were one of these animals for which were believed to only feel simple emotions, in the way a small child may. This may come as a surprise to dog-owners; most say that they feel their dog experiences, for example, guilt. Research has not been able to back this up and instead explains this by saying that when a dog conveys a sense of discomfort after doing something wrong, it is simply fear – fear of their owner’s reaction.
I am writing this article however because of recent news on dog’s and secondary emotion, in particular, jealousy. A recent study at the University of Auckland has concluded that dogs do feel jealous, a secondary emotion. It is a big step in recognising that secondary emotions may not be as unique as previously thought.
The experiment was conducted by measuring the force on which dogs pulled on a leash while watching their owner bend down, praise, and pet a model of a dog on the other side of the room. A control experiment (owner petting a fluffy cylinder) was set up alongside. Furthermore, psychologists also had a barrier set up during the experiment so that the dog could not see their owner above the waist. This meant that the dog’s reactions were prompted by mental imagery, indicating a more complex emotional process.