Mama's Last Hug Animal Emotions and What They Teach Us about Ourselves

Do animals experience joy, grief, or shame? Most people will be quick to attribute all sorts of emotions to pets and other animals. But many biologists remain uncomfortable with this, well, touchy-feely subject. As scientists, we are trained to be objective, cool, and detached when making observations. Anthropomorphism – the attribution of human traits to animals – has traditionally been a big no-no. But the tide is turning, and well-known Dutch-American primatologist Frans de Waal is here to help it along. Mama’s Last Hug is a smart, opinionated, and insightful book arguing we have long overestimated humans and underestimated animals.

The book opens with the final meeting between Mama, an old chimpanzee matriarch on her deathbed at Burgers Zoo in the Netherlands, and Dutch biologist Jan van Hooff, whom she had known for some 40 years. Should we be surprised by Mama’s capability to recall Jan? De Waal is strongly of the opinion that the school of behaviourism pioneered by the likes of B.F. Skinner and others has cast a long shadow over the study of animal behaviour. They see animals merely as stimulus-response machines driven by instincts and simple learning, and De Waal’s previous book Are We Smart Enough to Know How Smart Animals Are? was a passionate riposte to this mode of thinking. Mama’s Last Hug is the companion to that book, dealing with emotions, which De Waal considers fully integrated with cognition and intelligence (see also Descartes’ Error).

Before we proceed there is an important distinction to be made that De Waal returns to throughout the book. Emotions and feelings are not the same things, though they are often conflated in day-to-day speech. Emotions are bodily and mental states (fear, anger, desire) that drive behaviour. They show as facial expressions, gestures, odours, or changes in skin colour or vocal timbre. Feelings are subjective internal states only known to those who have them. Or as De Waal poetically puts it: “We show our emotions, but we talk about our feelings”. Emotions, therefore, can be observed and measured in the wild or in experimental settings. Feelings... well, making claims on what animals feel is a bridge too far even for De Waal. He thinks it is likely animals related to us have similar feelings, but he also recognises that this is pure conjecture for the moment.

And with that, De Waal launches into his book. In seven chapters he wanders widely, discussing his own and other’s research on primates and other animals; recounting engaging anecdotes of observations made in the wild or in captivity; and weaving in history lessons, explaining how the academic landscape of ethology (the study of animal behaviour) started, how it developed, and what has changed over the many decades of his own research career.

In passing, he deals with a range of emotions. Grief is particularly well publicised for elephants (see How Animals Grieve). Laughing and smiling are argued by Van Hooff to express different emotions in primates, but to have grown closer and often blend in humans. Empathy (sensitivity to another’s emotions) is widely documented in primates, where group members regularly comfort each other (see also De Waal’s earlier book The Age of Empathy). And the list goes on: disgust, shame, guilt, pride, hope, wrath, forgiveness, gratitude, envy... De Waal shows how all of these have been observed primates and other mammals. And where researchers have cared to look, some also show up in birds and fish (see Gifts of the Crow and What a Fish Knows).

This facet of the book is incredibly engaging and entertaining. But if I had to criticise something, it feels somewhat unstructured. De Waal wades in enthusiastically as there is so much to tell. He threads together one example and one emotion after another. But is this book more than just a collection of case studies? Yes, it is, but upon gathering my thoughts for this review I found I had to read between the lines to uncover what seems to be one of the main arguments. The blurb on the dustjacket mentions it quite prominently, but De Waal does not bring it up until halfway the book, on page 165. Emotions, he proposes, are like organs. Each one of them is vital and we share them with all other mammals.

What this boils down to is a reversal of the burden of proof. Rather than the default assumption of no animal emotions, we should assume that animals have emotions – those who wish to make the case they do not should be backing up that claim with evidence. Some may find this controversial, but from an evolutionary standpoint, it makes sense.

“Just look how similar our bodies are!”, exclaims De Waal. The musculature of primate and human faces – so important in emotional expression – is indistinguishable. When we eat something disgusting, both monkeys and humans pull the same face and the same brain area is active. The same antidepressants that work in humans can liven up bored fish, while rats and humans (and their brains) respond the same to drugs that induce a euphoric state. And remember all the hoopla around mirror neurons? They were discovered in macaques. De Waal mentions Sapolsky’s point that evolution strapped human emotions onto ancient emotions shared with other animals (see Behave). All of these examples reiterate the deep shared roots of the vertebrate neurological system.

It is not anthropomorphism we should worry about, but what De Waal calls anthropodenial. To assume that we are the only animals to experience emotions denies us our animal roots, reeks of human exceptionalism, and requires a belief in a unique cognitive spark, “a pretzel-like twist rather than the usual slow and smooth course of evolution [...] only because science has neglected what animals are capable of.”

This is another aspect of the book I thoroughly enjoyed: De Waal is outspoken. He rails against gratuitous anthropomorphism, dogmatic sociobiological theories, overly careful colleagues denying animals all emotions, behaviourism, moral philosophers who ignore emotions, and many other things. If I make him sound like an angry man, no, his disagreements are always reasonable and well-argued, but he has his opinions and is not afraid to voice them.

So, what does Mama’s Last Hug teach us about ourselves? That we are far less unique and share far more with our animal relatives than we think. That there are important lessons to be drawn on how we treat animals. And that we tell ourselves misleading stories about our past (e.g. on the purported deep history of warfare). De Waal brings a wealth of experience to the table and his writing is entertaining, stimulating, and thought-provoking. It makes Mama’s Last Hug a wonderful induction into the world of animal and human emotions.