Introduction

It has been suggested in the past that animals can only experience a few emotions and that the biggest difference between animals and humans is that animals can’t experience mixed emotions. However, more recent observations made clear that animals are also able to experience mixed emotions. When researchers talk about emotions in animals, the emotions are usually put between quotations and functional labels are preferred above emotional labels. However, it is likely that when to human related species respond similarly under similar circumstances, the emotions behind the response is also similar.

Action response caused by emotions

From an evolutionary point of view, emotions are strongly connected to instincts. That is way it was thought that we would experience fear as a response to a proposed threat, which is associated with a flight instinct. The evolutionary point of view didn’t gain ongoing support. Researchers found that emotions are associated with an altered bodily state, such as an increased heart rate, preparing the body for the fight or flight response. This is also known as the emotional response system and proposes that emotions are not strictly predetermined. The elicited behaviours depends on the context, making it possible to seek the most appropriate response to the circumstances. Within this view, emotions are interfacing environmental challenges and optimal behavioural responses.

Cognitions

Studies have shown that it is impossible to separate emotions from cognitions, because the brain has no separate cognitive and emotional pathways. These pathways overlap because of the need to coordinate functions and processes that are closely linked. In studies with animals, it has long been debated whether or not emotion and cognition were separable. Previously it was thought it was not, seeing animals as unable to understand the intentions of others. Nowadays, the view that for example monkeys are able to imitate behaviour consciously is supported. Studies have found that monkeys perform worse in comparison to human children in Theory of Mind tasks and social cognition tasks, but it is questionable whether this is caused by an inability or because of non efficient tasks.

When thinking about emotions and cognitions, the latter usually are thought to have a superior position. This view raises questions on the matter if there is a hierarchy in the brain between cortical and subcorticol brain areas. However, emotions are for from refelxiive and can be ‘chosen’ in correspondence with the environment. Being able to decouple the stimulus and the response is seen as an adaptation in survival and is also seen in some primates. This supports the idea that some primates have impulse-control and are able to mask their initial emotions.

Showing emotions

Most emotions are visible in facial expressions, both in human, primates and other visually orientated mammals. Darwin was the first one to examine this subject. He tried to show that human facial expressions constitute a shared heritage of our species, have parallels with the expression of other animals and he wanted to provide a behavioural argument for evolutionary continuity. The expression of emotions seems to be species-typical, within the species it’s the same, but there is a difference between the species. Homology is a concept of tracing back the traits of different species to a common ancestor. In this view, facial expressions may have different meanings in different species through a motivational and functional recasting. Contrary to homology is analogy, when similar traits are independent products of similar environmental changes.

The basis of empathy

Emotion contagion, adopting the same emotion as the other, forms the basis of empathy. It is proposed that empathy rests on a perception-action mechanism, which provides the observer access to the internal state of the other through neural activation. Empathy is crucial in social life, by converging internal states it brings individuals together. This is also seen in some animal species, including mammals.

Emotion research with animals is still under a lot of criticism, because we are not able to know exactly what animals are feeling or experiencing. However, this is also true for humans. Most shared behaviour relies on the assumption that others understand us, but this is only an assumption that also holds that humans are capable of perceiving their own emotions correctly. Emotions can be separated into three levels of experience. The first level consists of unconscious emotions. The second level consists of represented or felt emotions and the third level are reflected-upon feelings. When dealing with emotions, humans usually refer to the third level, but this isn’t the entire picture. However, not knowing what animals feel or think doesn’t stop the observations that primates can respond in very similar ways to humans when they are in a situation that elicits emotions in humans. This may assumes similar feelings, but we can’t know for sure with the current technology and insights.