How many times have you looked at your dog after he or she did something they shouldn’t and seen those soulful, apologetic eyes looking back at you? The look of guilt is obvious, but does that mean it is guilt as we understand it? How many times has your cat lain down on your laptop to say “stop ignoring me,” or acted aloof after you came back from a vacation? Animal emotions have intrigued and perplexed us for centuries. Now, we are discovering that many animals show a range of emotions that are very similar to our own.
From the earliest Greek and Roman philosophers until well into the 20th century, a prevailing scientific view was that animals were incapable of expressing emotions as humans do. Behaviors we associate with emotions in humans were dismissed as predetermined biological processes—the product of brains “hardwired” to produce a certain series of responses to a given scenario, independent of conscious thought.
Of course, many lay people (and an increasing number of scientists) will tell you differently. Those who interact with and observe animals on a regular basis can see that dogs, cats, birds, rodents, and even fish do experience basic emotions such as anger, fear, happiness, and sadness, and that more complex emotions, such as jealousy and empathy, are hardly rare.
“Emotion” describes a subjective, conscious experience with both physical and mental changes affecting behavior. Cognition is an important aspect of emotion, as an experience must be interpreted to generate an appropriate response. Emotions tend to be brief in duration and have consistent responses; however, emotions are also very personal and can be affected by numerous other factors. An event that evokes a response in one person or animal may not in another or at a different time or location. The complexity of emotions in humans makes emotions in animals even more inscrutable, as is demonstrated in the following specific examples of animal emotions.
Jealousy describes the negative thoughts and feelings of insecurity, fear, and anxiety that occur when an interloper threatens an important relationship. Jealousy requires the cognitive ability to determine self-esteem and weigh the rival’s threats. In a recent study by Harris et al. (PLoS One, 2014 ), scientists adapted a paradigm from human infant studies to examine jealousy in companion dogs. They had people lavish attention on objects, one of which was a realistic-looking stuffed dog that barked and whined, in front of their companion dogs. The interactions and the dog responses were recorded and analyzed. Nearly all of the dogs pushed at either the stuffed dog or the owner and almost one-third attempted to get between the object and their owner. Significantly, they did not exhibit these behaviors to the same degree when the object of affection was not dog-like. The authors say the results lend credence to the notion that dogs, like humans, do experience jealousy.
In popular culture, happiness and laughter were long thought to be unique to humans, even though scientists dating back to Charles Darwin have documented laugh-like vocalizations in chimpanzees and other great apes. Now, we are discovering that laughter is not limited to primates. In a 2012 article by Rygula et al., entitled “Laughing Rats Are Optimistic” (PLoS One, 2012), the scientists were able to elicit specific vocalizations, akin to laughter, when they subjected the rats to playful handling and tickling. They found that the tickling produced positive emotions and the rats were more likely to approach a tester’s hand when compared to those rats who were only handled (a finding also reported by AWI Refinement Grant recipients Drs. Sylvie Cloutier and Ruth Newberry in the Spring 2009 AWI Quarterly).
Empathy is the capacity to recognize and react to emotions that are being experienced by another. As such, it requires cognition and group interaction. A recent article by Reimert et al. (Physiology and Behavior, 2013), correlated a number of behaviors in pigs with positive (i.e. feeding and group housing) and negative (social isolation) events. They demonstrated that a positive behavior in one pig had a positive effect on nearby pigs. Similarly, pigs displaying the negative behaviors affected the surrounding pigs. The effects were not just limited to visible behaviors, as cortisol levels (i.e., stress hormone) in the pigs’ saliva confirmed their emotional state. The pigs were effectively demonstrating empathy toward their pen-mates, a concept that required them to understand the emotions of those around them.
Grief describes a complex set of emotional, physical, social, behavioral, and cognitive responses to a loss, particularly when a bond has been formed. Perhaps the most familiar form of grief is demonstrated by the mental and physical effects due to the loss of a loved one. Elephants have been observed gently touching the bones of dead elephants and carrying them around for days. In his book Elephant Destiny (2004), Martin Meredith described a herd of elephants interacting for several days with the body of a dead matriarch. They touched her body, tried to lift her, then threw dirt and branches over her to bury her. Her young calf wept and made crying sounds. Researchers have described many similar instances, even documenting a herd pausing silently at the site where a member died, years after her death. While there is no clear understanding of why elephants do this, the great interest in their dead provides strong evidence that elephants have a concept of death and are grieving in ways very similar to people.
These and other scientific studies confirm what many people already knew: many animal species have rich and complex mental lives. They are not automatons, directed solely by instinct and behavioral responses. Instead, like humans, they use their experiences to communicate emotions to those around them. Acknowledging that animals show emotions can be difficult, since it implies that we must pay more attention to their needs and wants—and to the pain we inflict upon them. Yet, when we do pay attention to those emotions, our interactions with animals become tremendously more fulfilling, and enrich our own emotional lives.