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

Mama’s Goodbye

In 2016, a chimpanzee named Mama lay dying in Burgers’ Zoo in Arnhem, the Netherlands. She was fifty-nine years old — ancient for a chimpanzee — and had been the dominant female of the colony for decades, the central figure around whom the group’s social life organised itself. Jan van Hooff, the Dutch biologist who had known Mama since 1972 and with whom she had a relationship of genuine mutual recognition, visited her in her final days.

The filmed reunion — Mama recognising her friend, her face transforming from the stillness of illness into something unmistakably like joy, reaching out to embrace him, patting his head with the precise gesture she had used throughout their decades of acquaintance — was viewed by millions online and became something close to viral. De Waal opens his book with this moment, uses it as the occasion for everything that follows, and returns to it at the end.

Mama’s Last Hug is de Waal’s most emotionally accessible book — a summation of decades of observation and research on animal emotional life, presented through stories and science that are inseparable from each other in the way that characterises his best work.

The Science of Animal Emotion

The scientific study of animal emotion has been constrained for most of its history by two competing methodological errors. The first is anthropomorphism: the attribution of human emotional experience to animals based on superficial similarity, without evidence of the underlying mechanisms. The second — less often named but at least as common — is what de Waal calls “anthropodenial”: the denial of emotional experience in animals because it would be inconvenient, because it complicates their use as research subjects and food sources, or because some version of human exceptionalism requires it.

De Waal’s career has been a sustained argument against both errors and for a third approach: the careful, evidence-based study of emotional states in animals as functional systems — as states that motivate and organise behaviour, influence social relationships, and reveal the structure of a given species’ inner life. By this approach, the question is not “do animals feel what we feel?” but “what emotional states are present in this animal, and what do they do?”

The answers, accumulated over decades of research that Mama’s Last Hug synthesises, are consistently more complex than scientific orthodoxy has acknowledged. Animals demonstrate functional fear, joy, grief, attachment, disgust, and surprise in forms that parallel human emotional experience without being identical to it. They also demonstrate states that challenge the traditional human-animal boundary: shame, embarrassment, a sense of fairness, what appears to be gratitude, and what appears to be mourning.

Embarrassment and Shame

The book’s most original contribution is its treatment of what de Waal calls the “self-conscious emotions” — emotions like shame, pride, and embarrassment that require some form of self-awareness and social sensitivity. These have traditionally been presented as uniquely human, dependent on the kind of reflective self-consciousness that only humans are thought to possess.

The evidence suggests this is wrong. De Waal describes observed chimpanzee behaviour after public failure — losing a fight in front of the group, falling off a branch, being caught stealing — that has the functional signature of embarrassment: avoidance of eye contact, self-directed grooming, movement away from observers, reduced social participation. He describes cases that appear to involve shame — the specific response to having violated a social norm rather than simply having failed. He describes the facial expressions associated with these states, which are distinct from fear or pain responses.

None of this proves that chimpanzees “feel embarrassed” in the phenomenological sense that humans do. But it is evidence that the functional system we call embarrassment — a response to public failure that motivates withdrawal and behavioral adjustment — exists in non-human form. That functional continuity is what the evolutionary perspective predicts: emotions didn’t spring fully formed into existence with Homo sapiens, but evolved gradually from simpler precursors.

The Fairness Sense

One of the most discussed findings in animal cognition research is the demonstration by de Waal and his colleagues that capuchin monkeys will reject unequal pay for equal work. A capuchin given a cucumber slice as reward for a task will accept it contentedly — until it sees a neighbouring capuchin receive a grape (a preferred reward) for the same task. At that point, the first capuchin will often refuse the cucumber, sometimes throwing it back at the experimenter. The visible emotional response resembles what we call indignation.

This is not envy in a sophisticated sense — the capuchin isn’t calculating relative social status and responding to a perceived injustice. But it is, de Waal argues, the functional precursor of the human sense of fairness: a response to differential treatment that registers as wrong, motivates rejection, and produces visible emotional expression. The evolutionary continuity from this response to human moral intuitions about fairness is not unbroken, but it is real.

Grief and Attachment

The book’s most affecting passages deal with animal grief — the responses of social animals to the deaths of group members, particularly of close social partners. Chimpanzees, elephants, dolphins, and corvids all display behaviours that have the functional signature of grief: withdrawal, reduced activity, return to the site of death, prolonged presence near the body.

What’s particularly striking about these observations is what they reveal about the strength of social bonds in animal groups. The grief response is calibrated to the relationship — more intense for closely bonded partners, less intense or absent for peripheral group members. This suggests that the emotional architecture underlying social bonds in these species is more complex than simple association or familiarity. Something that functions like attachment — like care, like valuing another individual’s continued presence — is present and is registered when it is lost.

The Frame

De Waal frames the book with Mama’s farewell not because it proves anything that the research alone couldn’t prove, but because it presents the emotional reality in a form that bypasses the defences readers bring to scientific argument. The filmed reunion makes visible — to anyone who watches it — something that the data support but that the data cannot quite convey: that what is happening between Mama and Jan van Hooff is mutual recognition, mutual care, and something that, whatever we want to call it, produces in both of them the expression of something that matters.

The science tells us this is not anomalous — that it is an instance of the general principle that complex social species form strong individual bonds with specific others, and that these bonds produce states that motivate and organise behaviour in ways that parallel human love and friendship. The film makes it present. The combination is what makes Mama’s Last Hug de Waal’s most moving book.

Our rating: 4.4/5 — De Waal’s most accessible and emotionally resonant work. The science of animal emotion has never been presented with more warmth or more rigour.