What goes on in the minds of chickens and other animals? “They have more complex emotional lives than is often thought.”

From monkeys and crows to octopuses and chickens: new technologies and ingenious experiments give us more and more insight into the emotional lives of animals. How similar is this to what we have, and what are the implications?

“For me, an animal is a person, not a thing,” Fairlie Baetens said through tears after her arrival. Only Elvis survives Part of it has been shown My octopus teacher. In this Oscar-winning recipe for calamari, we follow documentary filmmaker Craig Foster, who builds a special relationship with an intelligent octopus. Baetens used this piece to complain that the way we treat animals is in stark contrast to their rich emotional lives and capacity for suffering.

American biologist Mark Peikoff, author of The emotional life of animals A convinced vegetarian, he agrees with Baetens. “It’s about who we eat and whom we keep in cages, not what,” Bekoff writes. “Words matter.”

Thanks to new technologies and original experiments, scientists are increasingly succeeding in measuring emotions in animals in a subtle way, for example by means of hormones in saliva. They use what’s called a cognitive bias test to measure the animals’ mental state. “This experiment is a game-changer,” says behavioral biologist Jörg Maassen (Utrecht University). “It gives us a glimpse into the inner world of animals.”

In this experiment, animals learn that a particular stimulus, such as opening a door, is associated with a reward. If another door opens, there will be no reward. If you then present the animal with an unclear stimulus, such as a door opening in the middle, it is likely to value the opportunity for a reward “optimistically” or “pessimistically,” depending on what it has experienced before.

Bees

Bees can also see the cup as half full or empty in such an experiment. British biologists have found that bees see things rosier when they have just drunk a little sugar solution than when they were first shaken. According to the researchers, this is an indication that even bees can be in an “emotion-like” state. “Better research gives us more and more knowledge about what happens in animals,” says cognitive psychologist Mariska Kreit (Leiden University). “Although it is still very difficult to know what an animal is really feeling. It is difficult to determine that in another human being, let alone an animal.

Now take this octopus. It is exceptionally intelligent for a mollusk, and is closely related to mussels and snails, animals not known for their intelligence. But the octopus’s brain contains about 500 million neurons, equivalent to the number of dogs and some species of small monkeys. Judging by the number of neurons, you might think that an octopus is a mammal.

However, this brain is radically different – ​​not surprising when you consider that the last common ancestor of humans and octopuses lived about 600 million years ago. Two-thirds of the neurons are located in the beast’s bosom. Evolution seems to have found two very different ways to build powerful brains. Contact with an octopus is, according to Australian philosopher of science Peter Godfrey-Smith, “the closest we will ever come to meeting an intelligent alien being.”

Sandy plain

“Octopuses have cognitive abilities that we previously associated with species such as dolphins, great apes, and intelligent birds such as corvids and parrots,” says biologist Eve Seuintjens, who studies the brain evolution of octopuses at the University of Leuven. The animals appear to be playing, using tools, and making plans. If the octopus has to cross an open sandy area, it takes coconut shells with it to hide in.

They appear to feel pain in a conscious way and do not simply react reflexively to the painful stimulus. In a recent study, scientists gave octopuses a painful injection in the arm and placed them in a room with a specific pattern on the walls. When the animals were later given a choice between two rooms, they moved away from the room in which they had received the injection. According to the researchers, this suggests that octopuses consciously feel pain like mammals.

In his book My mother’s last hug Primatologist Frans de Waal argues that you cannot deny that many animals have rich mental lives. The title refers to the recent meeting between Mama, a 58-year-old female chimpanzee, and biologist Jan van Hove, who has known her for forty years. The chimpanzee lies listless in the hay, but when she recognizes Van Hoof, she smiles and hugs him. You have to make an effort not to see affection and joy.

For decades, biologists have been extremely reluctant to attribute emotions to animals. Anyone who did so was guilty of anthropomorphism. “Why did we go to so much effort to deny something so obvious?” De Waal asks. “Given how similar animals are to us, how they share our physiological responses, have the same facial expressions and the same type of brain, wouldn’t it be strange if their internal experience were so radically different?”

“Projecting human emotions onto animals is not wrong,” concludes American science writer Carl Safina. “It’s our first best guess.” There is now no dispute that many animal species experience emotions, although it is not always clear to what extent they experience these emotions in the same way that we do.

Biologists generally view emotions as measurable physical responses. For example, when we feel stressed, our heart rate increases and we produce more cortisol. Although some scholars use emotions and feelings synonymously, most say that feelings go further than that. “Emotion is the conscious experience of emotion, a state of mind that cannot be observed,” says Crete. “They add an extra layer to the experience, as it were.”

Different animal species seem to have insight into their own abilities and emotions and those of others. Rhesus monkeys are aware of what they know and what they don’t know, and in an American study they chose to pass a memory test when they expected to fail. Mice will free a trapped colleague if given the opportunity, without being rewarded, suggesting that the animals have empathy.

Given how widespread advanced cognitive abilities are in the animal kingdom, it is reasonable to assume that some species have a human-like form of consciousness, say Crete, Massen, and de Waal in a recent paper in the journal. Affective sciences. Until proven otherwise, they believe it is best to assume that similar behavior indicates similar feelings, and sometimes similar emotions.

In fact, complex traits do not usually appear out of nowhere in the course of evolution. Something as complex as an eye exists in various forms and degrees of complexity, ranging from simple light sensors in single-celled organisms. “It seems counterintuitive to me that only humans have feelings,” Krit says. “It is assumed that consciousness and feelings exist to different degrees in animal species.”

Without anesthesia

Research on the cognitive abilities of animals often focuses on species known for their intelligence, such as monkeys and corvids. But the more scientists search for special mental abilities in other species, the more they will find. “That’s why it’s important that we do more research on this and take it into account in animal welfare regulations,” says Crete.

“Chickens have greater cognitive abilities and more complex emotional lives than has often been thought,” says Frank Tuetjens, an animal welfare expert from the Institute of Agricultural, Fisheries and Food Research (ILVO). In the trade magazine Behavioral science Researchers list what they are capable of. Chickens can add and subtract and understand that something that disappears from sight is not really gone. On memory tests, chickens also score well, sometimes better than primates. They seem to be capable of self-control and will give up a small immediate reward in order to obtain a larger reward later.

Chickens have personality traits such as curiosity, fearfulness, aggression, and are bored, frustrated, and happy. They care about the state of mind of others. They react tensely when others of their own kind are treated harshly. According to the researchers, this suggests that their emotions are “contagious” and they may have empathy. The scientists concluded that a better understanding of chickens’ cognitive development should encourage “greater respect and concern for their well-being.”

Tweets points out the ethical implications. “The more complex an animal’s emotional life is, the more important it is not to compromise their well-being,” says Toytens. “At the same time, it is difficult to meet the complex needs of these animals. So it causes a great deal of cognitive dissonance when the animals we exploit turn out to have complex emotional lives.”

Masen sees parallels with how, until the 1980s, scientists were convinced that children couldn’t feel pain because their bodies and brains worked differently. So they were performed without anesthesia. “Now we look at it with disbelief,” says Maassen. “I think we will also look at what we once thought about the emotional lives of animals.”