Many biologists and psychologists shy away from attributing feelings to animals. Wrongly, say three scientists in an opinion piece.

In everyday speech we hardly distinguish between emotions and feelings. Yet they are two different things, write psychologist Mariska Kret (Leiden University), biologist Jorg Massen (Utrecht University) and primatologist Frans de Waal (Emory University, USA) in the scientific journal Affective Science† And although feelings are difficult to measure, according to the three scientists we should not just assume that animals do not have them.

Emotions and feelings

What then is the difference between emotions and feelings? In short, an emotion is a reaction of your body to something that happens, after which you adjust your behavior. “Emotions can exist without feelings and influence behavior more often than we think”, write Kret, Massen and De Waal.

In many animals, emotions are measured in a variety of ways (via behavior, heart rate or amounts of certain hormones, for example). Therefore, it is not very controversial to say that animals can have them.

Otherwise it is with feelings. It describes De Kret in a news item from Leiden University as “the subjective interpretation of one’s emotions”. And well, it can’t really be measured objectively.

We humans do know about ourselves that we have feelings – but that is the only direct evidence of it. Moreover, we do not always know what we are feeling, write De Kret and colleagues: “Many people visit a therapist to find out.” We also often give a socially desirable answer when we are asked about our feelings. So you can ask yourself to what extent you can objectively examine people’s feelings.

Evolutionary Thrift

In the meantime, all kinds of experiments have been done on animals that strongly give the impression that they are aware of themselves to a certain extent. For example, different animal species recognize themselves in a mirror and rhesus monkeys seem to know what they do and don’t know† “We think it is premature to assume that these species are not aware of their emotions”, say De Kret, Massen and De Waal.

One way of looking at these kinds of observations is ‘cognitive frugality’. That is, when you interpret animal behaviour, you should start from the simplest process that can explain this behaviour. In that case, you might argue that it’s best to ignore your feelings until you can “measure” them.

Take, for example, a monkey that very carefully moves away from a snake while it stares at the predator and lets out soft shrieks. If you value cognitive thrift, then don’t say the monkey “feels scared.” Instead, you should assume that the animal’s behavior is unconsciously controlled.

De Kret and colleagues oppose this with another principle: that of the evolutionary thrift. This means that if an animal closely related to us, such as a chimpanzee, exhibits similar behavior under similar circumstances, it is likely that similar psychological processes are behind it. And that can include feelings.