Last night, I headed down to the beautiful Bell House, in the Gowanus section of Brooklyn, for this month's Secret Science Club lecture, which featured the triumphant return of Dr Frans de Waal, Emory University primatologist and psychologist, director of the Living Links Center at Yerkes National Primate Research Center, living legend, and one of my heroes. Dr de Waal delivered a Secret Science Club lecture Dr de Waal delivered a Secret Science Club lecture in April 2016 on animal cognition. Last night's lecture, riffing on his latest book, Mama's Last Hug: Animal Emotions and What They Tell Us About Ourselves, concerned, you guessed it, animal emotions.
Dr de Waal began his lecture by mentioning Charles Darwin's book The Expression of the Emotions in Man and Animals and noting that this book had fallen out of favor by the time he was a student. Scholars used to be able to talk about animal motions, but he was told as a student not to talk about thinking, feeling, or any inner states. The main objection to discussing inner states was the sin of anthropomorphism, (mis)attributing human feelings to non-human animals. Another objection is our inability to know what animals feel.
In Darwin's model of emotions, stimulus leads to emotion which leads to action, and emotions must lead to adaptive responses. For example, fear can lead to hiding. An alternate model of emotion, proposed by William James and Carl Lange, held that stimulus led to action which was the basis of emotion. The current model is that stimulus leads to emotion which leads to action and feelings. Actions are adaptive and feelings are awareness of emotion. Dr de Waal stated that he cannot know an animal's feelings, he cannot know your feelings, feelings are hard to access... not knowing how an animal feels does not mean that he cannot study its emotions.
Dr de Waal then tackled the subject of anthropomorphism, the 'sin' of attributing human characteristics to animals. In some cases, similar seeming behavior is due to convergent evolution, a process by which organisms which are not closely related appear to be similar due to adaptation- by independently adapting to similar environments, they end up looking similar. homology, on the other hand, involves similar traits shared by closely related organisms being due to shared ancestry. Dr de Waal contrasted two kisses... when kissing gouramis 'kiss', they lock their mouths in a form of fighting. Bonobos, which are closely related to humans, kiss for reasons similar to human reasons for kissing. In the case of bonobos, there is homology with human kisses, while the mouth-to-mouth contact of gouramis does not represent homology. Similarly, a chimpanzee forelimb, with its homologous structures, is referred to as a hand rather than a paw (as an aside, I have to note that this courtesy is not extended to monkeys). Dr de Waal showed us a picture of a baby gorilla laughing and quipped that, in the interest of avoiding anthropomorphism, this would be characterized as 'short vocalized panting', which elicited short vocalized panting from the audience. When a baby gorilla, a close relative of humans, laughs for reasons which would make humans laugh, call it a laugh, not vocalized panting.
Dr de Waal coined the term 'anthropodenial' to denote an a priori denial that other animals can have mental experiences or that humans are like animals. He opined that anthropodenial is more dangerous than anthropomorphism- the belief that humans are separate from nature is a major factor in our current ecological catastrophe.
When studying emotions, Dr de Waal advised us to start with the face, the window to the soul. Chimpanzees have as many facial muscles as humans. Inspired by Darwin, Dr Paul Ekman was a pioneer of the study of emotion. When Dr Ekman began his study of emotion, the prevailing belief was that emotions were expressed differently in different cultures- when he looked into this belief, there were no records, no photos... this belief was all in the theorists' heads. Dr Ekman studied emotions and categorized six major emotions: disgust, sadness, happiness,fear,anger, surprise. This model is still somewhat constraining, as there are subtler emotional expressions.
Dr de Waal's professor, Dr Jan Van Hooff, studied emotions and recognized differences between laughing and smiling. While smiling was thought to be a 'lower' version of laughing, Dr Van Hooff discovered that smiles are based on teeth baring behavior (often used to show aggression or submission) while laughter is rooting in play expressions. There are variations in behavior, nervous smiles and aggressive laughter. Aristotle famously wrote 'man is the only animal which laughs', but chimpanzees laugh under similar conditions that humans do. Chimps have the same tickle response that humans do:
Even though rats are ubiquitous lab animals, it was long thought that they didn't exhibit emotion through facial expressions, but when this was finally tested, it turns out that these animals were underestimated. Dr Jaak Panksepp even discovered that rats respond to tickling with ultrasonic laughter:
Showing us the video of the laughing rat, Dr de Waal joked, "As a student, I had a bunch of rats, they tend to multiply."
Studies of humor among apes are relatively new. In one instance, a zoo employee in a mask startled chimpanzees in a zoo, eliciting anger responses. On his last masked escapade, he took off his mask, and the chimpanzees laughed, suggesting that, like humans, they are amused by incongruity. Unexpected endings lead to laughter. When an alpha male allows a baby to chase him, it's funny. When a chimpanzee tricks her son and steals his nut-cracking rocks, she laughs afterwards:
An orangutan can be made to laugh with a simple magic trick:
Laughing represents a loss of control, it can be seen as animalistic- you can pee yourself, you need to catch your breath... why can't people just say 'this is funny'? Dr de Waal showed a video of Bill Clinton laughing uncontrollably, and causing Boris Yeltsin to laugh until he tears up:
A lot of emotional expressions affect our bodies deeply. The problem with the basic theory of emotion is that it is hard to study emotions that have no 'face'. Love, attachment, jealousy, hope, empathy... there are no facial expressions for them. Also, there are animals that don't expression emotions facially, such as cats and dolphins. Dr de Waal cited the example of the grieving orca which carried the body of its deceased young around for seventeen days. Chimpanzees are emotional beings, they express their emotion on reuniting with each other vocally.
Dr de Waal posed several questions: Are there uniquely human emotions? Are animals 'captives of the present'? Are humans the only animals with impulse control? Do only humans know disgust? He noted that he found this question the strangest of them all.
We don't know what animals feel, so the question of uniquely human emotions is unverifiable.
Regarding the notion that animals live only in the present, forgiveness involves a knowledge of the past. After fights, chimps engage in reconciliation- they have conflict resolution to shift from aggression to friendliness. The model for conflict resolution involves PC/MC (post-conflict/matched-control) observation, the reconciliation model is found in the wild and in captivity. Dr de Waal joked that he is from a family with six boys, so he is familiar with reconciliation. Besides primates, reconciliation behavior has been observed in most mammals- goats, hyenas, dolphins all reconcile. In an aside which I found particularly funny, he noted that reconciliation has not been observed in domestic cats. Among human preschoolers, reconciliation behavior was observed, and it was handled better by Japanese children than American children, probably because American teachers intervene in conflicts more frequently.
Dr de Waal displayed some pictures of Barack Obama and John McCain after a particularly contentious meeting, and Barack Obama has his cheeks puffed with air. A similar puffed cheek, bulging lip expression is used by male chimpanzees, and politicians such as Anthony Weiner, Bill Clinton, and others, probably to express regret. This expression is a male behavior, women don't do it.
Besides reconciling for past behaviors, animals also plan for the future. Psychologist Dr Wolfgang Köhler tasked chimpanzees with obtaining fruit that was hanging from the ceiling. The chimps were provided with boxes and poles and were able to employ them to get their reward. Köhler noted that the chimps solved the problem in their heads, not by a laborious trial-and-error process. Dr de Waal joked that this made him very unpopular with behaviorists. When he replicated the Köhler experiment, one particular female chimpanzee solved the problem by throwing a box and bringing down the fruit... she was the chimpanzee which brought down the drone:
Chimps can plan ahead, the collect tools and move them to areas where resources are available- they are not trapped in the present.
Animals can also exhibit impulse control. The standard laboratory test for impulse control is the marshmallow test:
Chimpanzees, like the children in the video, look around at other objects to distract themselves from temptation, they can hold out longer if given toys. Even some birds are able to pass the marshmallow test, with one African grey parrot holding out for fifteen minutes. Animals can control their impulses, such as a cat stalking a chipmunk rather than pouncing prematurely.
Subordinate animals in a hierarchy also exhibit impulse control. In the Menzel test, a chimpanzee is separated from the group and shown a hidden cache of food, which it must keep concealed from dominant chimps. Near the food source, the chimp will act nonchalant, an act of deception. If a low-value cucumber and a high-value banana are hidden, the aware chimp will sometimes lead the dominant chimp to the cucumber and grab the banana while the dominant one is occupied.
Animals feel disgust, it is an important adaptation to avoid contaminants and poisons. Psychologist Dr Paul Rozin opined that disgust seems to be uniquely human and is entirely or primarily cultural. Dogs were held up as exemplars of animals' lack of disgust- they eat feces and lick their testicles. Dogs do exhibit disgust, but only when presented with stimuli which disgust them, such as lemons:
Chimpanzees don't like the rain, and they try to keep their hands dry, hunching over and covering them. They tend to exhibit the wrinkled-nose disgust display when outside in the rain.
In one experiment, food was placed on plastic replica feces and real feces and macaques were observed eating food placed on plastic feces while rejecting the food placed on real feces.
Dr de Waal then discussed Dr Sarah Brosnan's primate fairness study, in which capuchin monkeys were given unequal rewards (a meh cucumber or a prized grape) for performing a task. The monkey receiving the poor reward doesn't take things well:
Inequity aversion is an irrational response- rationally, you should always take what you get. Reject the reward and you get nothing. Chimpanzees subjected to this test will sometimes refuse a grape until the other chimp gets a grape. Dr de Waal joked that this inequity aversion is lost in humans- one percent of us are grape monkeys, while ninety-nine percent of us are cucumber monkeys. In a not-so-funny coda, he noted that this is undermining our societies.
On a lighter note, parents are now doing this experiment on their children, giving one kid a whole cookie and another kid half of one. Dr de Waal also recounted a colleague who has a Great Dane and a Chihuahua which want the same amount of food.
Dr de Waal summed up his take on anthropomorphism: if two related species have the same response to the same stimulus, use the same term. Don't separate animals from humans.
Dr de Waal ended his lecture on a poignant note, addressing consolation behavior. All mammals show empathic concern. Among elephants, consolation takes the form of vulnerable contact- an elephant will stick its trunks in another elephant's mouth, a display of trust. Dr de Waal then turned to the subject of his book Mama's Last Hug. Mama was the alpha female of the Royal Burgers Zoo (Arnhem, Netherlands) chimpanzee colony. She was the most powerful chimpanzee in the colony, a mediator and decision maker, and important contact with human researchers- when she died, conflict arose in the group. At the age of eighty, Dr de Waal's professor, Dr Jan van Hooff, visited Mama, aged fifty-nine, as she was dying. Dr de Waal described the visit as 'two aging hominids meeting'. Typically, because chimpanzees are stronger than humans and are potentially dangerous, all interaction is done through a cage. On this occasion, Dr van Hooff decided to forego protocol and enter the enclosure to pay his final respects to Mama:
The hug, the arm around the neck and the patting, is reassuring behavior. Some viewers didn't expect such an emotional reaction and he felt the need to explain. Animal emotions can be studied objectively, cortisol levels and heart rates can be measured. Humans have no organs that aren't in a rat's body, while our emotions may be more sophisticated, they are not that different.
The lecture was followed by a Q&A session. One question regarded bad emotions- Dr de Waal noted that animals do kill conspecific animals in conflicts over mates, hierarchical positions, territory. Another questioner asked, do animals have emotions that humans don't have? Dr de Waal noted that cetaceans may have stronger affiliative feelings (which may be a factor in mass strandings), but the basics are similar. To find something foreign to human experience, one might have to look at more distantly related animals, such as octopodes. Regarding the lack of reconciliation among cats, Dr de Waal noted that domestic cats are solitary hunters, so they have less of a need of affiliation than other mammals. Lions, being social, might exhibit reconciliation behavior, but this needs further study. Another question involved altruism- the origin of empathy is thought to be parental care, in which the hormone oxytocin plays a role. Chimpanzees share food, but this may be a case of reciprocity, rather than altruism. Sharing just makes sense. The house was packed, so the Bastard was unable to get a question in until the post lecture book signing, when he asked Dr de Waal about the role of olfaction in the expression of emotion, and how this could be measured. As a primatologist who studies apes, he noted that smell doesn't play as big a role as visual and vocal cues, but that other mammals might communicate that way. The bastard also thanked Dr de Waal for his kindness to linking to the blog.
Once again, the Secret Science Club served up a fantastic program. Dr de Waal's lecture informed, enthralled, saddened, and amused- how appropriate for a lecture on emotions. To use a baseball term, he knocked it out of the park. Kudos to the good doctor, Margaret and Dorian, and the staff of the beautiful Bell House.
Here's a recent interview with Dr de Waal concerning the topic of the lecture:
Pour yourself a nice beverage and soak in that SCIENCE!