The Ethologist Jordi Casamitjana reviews the book for young adults “Love in Their Hearts”, written by the vegan ethologist Marc Bekoff and young-adults author Jeff Campbell.
Most people don’t know the word.
I have been an ethologist for most of my adult life, but whenever I introduce myself as one, I can often tell from people’s faces that they don’t really know what I mean.
I am also a zoologist and a biologist because I went through a five-year degree in which I first qualified as a biologist and then as a zoologist, before going on with my PhD studies on the ethology of social wasps. Although everybody knows what biology is, and most people know what zoology is — although sometimes I realise they don’t, thinking it has something to do with running a zoo — not many non-scientists in the UK (where I live) know what ethology is. In Anglo-Saxon countries, the term is not commonly used (instead, people tend to say, “animal behaviour scientist”), but in the rest of Europe it is much more common.
Ethology is the comparative study of animal behaviour, primarily by observing wild animals in their natural environments. Traditionally, it differs from the American school of animal behaviouralists, which historically focused more on experimental studies in captivity than on observing animals in the wild. When in 1973 the Austrian Konrad Lorenz, the Dutch Niko Tinbergen, and the German-Austrian Karl von Frisch won the Nobel Prize for their discoveries on animal behaviour, the scientific discipline of Ethology became established.
Although I am not currently an academic, I often introduce myself as an ethologist because that was my vocation and training, and I have been applying it to my animal protection work. I always wanted to be out in nature, far removed from human interference, quietly observing animals and learning how they think and behave. That’s why I am always delighted whenever I meet another ethologist, instinctively greeting them as though we were professional colleagues.
That’s exactly what happened when I first conversed with Dr Marc Bekoff, a renowned ethologist now living in Colorado, who has studied animals all over the world. I had the good fortune to interview him a few years ago for one of my Vegan FTA articles about his life as a vegan and his remarkable body of work, which includes many outstanding books.
Since that interview, we have stayed in touch, which has been amazing because Marc is such an important figure in the field, but also a very friendly and decent human being. We have exchanged information over the years, I have sent him some of my articles, and he has kindly shared them. I am especially grateful because he also generously provided a quote for my latest book, Why Vegans Don’t: A Philosophical Guide to Vegan Behaviour.
With all that in mind, I was especially pleased to learn that he had published a new book, and Vegan FTA asked me if I would review it. This one was written for young adults (or older children), which made it particularly interesting to me because I haven’t reviewed many books for that age group.
The book is called Love in Their Hearts: A Celebration of Animal Emotions and a Guide to Compassionate Action, and it is co-authored by Jeff Campbell.
The following is my review.
Similar Themes, Different Audience
Marc Bekoff is one of the world’s best-known contemporary ethologists and among the pioneers in bringing the scientific study of animal emotions into the public eye. Professor Emeritus of Ecology and Evolutionary Biology at the University of Colorado, he has spent decades studying animal behaviour, cognition, play, cooperation, empathy and compassion in a wide variety of species. Throughout his academic career, he has combined rigorous science with a deep ethical concern for our relationship with other animals, becoming one of the leading voices advocating that the overwhelming evidence of Nonhuman Animal sentience should change how humans treat them.
He has been vegan for decades. In 2024, he said to me, “Over time, I became vegetarian. In the late 1980s, I just did it — I call it ‘going cold tofu’ instead of ‘cold turkey’. For the next ten or so years, the only thing I ate that wasn’t vegan was a piece of cheese or an egg once a month. People used to ask me, and I was honest. I’d say that my diet was 99% vegan by bulk and calories. Then, one day, a young girl asked me something like, ‘Why do you have to have that little cheese a month?’, and my response was simple, ‘I don’t.’ And that was it. That was between 22 and 25 years ago. It was not a difficult choice — I really mean that.”
He has published more than 30 books, as well as hundreds of scientific and popular articles, and has received numerous honours, including a Guggenheim Fellowship and the Animal Behaviour Society’s Exemplar Award.
Many readers will already know some of his most influential books, which include, The Emotional Lives of Animals: A Leading Scientist Explores Animal Joy, Sorrow, and Empathy―and Why They Matter, The Animals’ Agenda: Freedom, Compassion, and Coexistence in the Human Age (with Jessica Pierce), Rewilding Our Hearts: Building Pathways of Compassion and Coexistence, Canine Confidential: Why Dogs Do What They Do, Unleashing Your Dog: A Field Guide to Giving Your Canine Companion the Best Life Possible, A Dog’s World: Imagining the Lives of Dogs in a World Without Humans, and Dogs Demystified: An A to Z Guide to All Things Canine. I read most of these, and they are very accessible, informative, and interesting. Together, these works have helped transform the public conversation about Nonhuman Animal minds, emotions and ethics.
His latest book is Love in Their Hearts: A Celebration of Animal Emotions and a Guide to Compassionate Action, but this one, although it pretty much deals with his main subject (animal emotions) it was written for a younger audience with Jeff Campbell, an award-winning author of young adult non-fiction, who has also spent many years working as a professional editor and writing teacher. In fact, he has edited several of Marc’s previous books, making Love in Their Hearts the first book on which they appear together as co-authors. Other nonfiction books Jeff has written for young adults include Daisy to the Rescue, Last of the Giants, and Glowing Bunnies!?, which was named the Best Book for Teens 2023 by the New York Public Library and was a SCBWI Golden Kite Award finalist.
Published in June 2026 by Armin Lear Press and distributed from the Netherlands by Media Boekservice, Love in Their Hearts, although aimed primarily at young adults, can be enjoyed equally by anyone with an interest in animals, nature and ethics. The book explores the rich emotional lives of animals through a combination of scientific research, true stories, and observations from leading field researchers. Moving from dogs and dolphins to octopuses, chimps, bees and bears, it examines the growing body of evidence showing that many animals experience emotions such as love, empathy, grief, curiosity, playfulness and even anger (each of these emotions leading a chapter in the book). More importantly, it invites readers to consider what these discoveries should mean for the way we relate to our fellow animals and encourages compassionate action based on both scientific understanding and empathy.
The book opens with a foreword by Dr Jane Goodall, a close friend of Marc. Her pioneering long-term study of wild chimpanzees transformed our understanding of animal behaviour, while her decades of work in conservation and education have inspired generations of scientists, naturalists and animal advocates around the world. Sadly, she passed away after writing the foreword but before the publication of the book.
Engaging, Informative, and Light
I must admit that, before reading the book, I had to look at the official definition of “young adults” from a publishing point of view, because I suspected it was not literal. I was right, as it means readers between 12 and 18 years old (all “teens”, none of them considered legal adults in most jurisdictions, but some of them allowed to vote in official elections in over 12 countries). This helped me to use my memory and imagination to transport me to the time in my own biography when I fell into that age bracket, so I could try to read the book with the brain I had then.
I cannot claim I was successful in sponging out the last 45 years of experience from my mind, but whatever approximation I achieved gave me an unequivocal conclusion: I would have loved this book so much!
At that age, I was just an aspiring ethologist, probably having found the word “ethology” for the first time when I read Konrad Lorenz’s book On Aggression (published the year before I was born in Catalonia under the fascist dictatorship of General Franco — which would have made the book unavailable to me until he died in 1975, two years after Lorenz got his Nobel Prize). Had I read then Love in Their Hearts, I would have learnt so much! It would have guided me so quickly toward what I tried to become years later: a compassionate scientist who cares about Nonhuman Animals as individuals and wants to protect them as much as study them.
Any young aspiring ethologist today, despite the huge amount of information available to them at their fingertips, would equally love it and learn from it, because one of the best things about the book is that it displays with perfect descriptions the work of many ethologists. It not only tells you what they found, but especially what they felt, making it look “real”, and undoubtedly carrying a huge amount of inspiring potential that raw and cold information could not hold. As you would expect, the book centres on Nonhuman Animals, but the people who observe and study them are also a key feature of it. This would make any aspiring zoologist or biologist think “I want to be like them”, and probably channel their aspirations not only toward ethology, but also toward compassion and ethical behaviour.
The style of the book is critical for its inspirational nature. It is not heavy; it’s clear and engaging; it’s not full of empty references and disembodied names, and it allows you to jump from story to story, from anecdote to anecdote, at your pace. I can see how it would work for a teen mind because it’s not “instructional”. It does not give you a “lesson” of ethology. It does not talk down to you as a teacher would. It converses with you at the same level, telling you, respectfully, “this is what I have learnt, if this is of interest to you.”
There is a stylistic device that surprised me, though, but I think I understand why it was used. Most of the book is written in third person, and the authors’ names often appeared as “Marc thinks” or “Jeff found”, as if the whole thing was written by a third mysterious author. I must admit that, at first, it confused me a bit, having been accustomed to books of this nature always being written in first person (and all those I read from Marc were written in this way). However, I then realised that this book does not follow the classical two-author formula where one author writes some chapters, and the other writes the rest. No, in this book, unless stated otherwise in some sections, both authors are writing all the text “together”, so referring to each would make sense as if, rather than writing, we were all in the same room talking (the two authors and the reader). This is precisely why I think it would work for a young reader, as it removed the “authoritative” feel that might trigger a distance from the rebellion-prone teen. I think that’s very clever, and probably Jeff had a lot to do with it.
I think the format is perfect. There are many photos around the book that give the needed illustration of the characters discussed, and, now and then, there is a box with non-patronising explanations of key concepts that would help the young reader to consolidate the terms they just learnt (or learnt not that long ago but perhaps forgot). That makes the reading very light and not overwhelming. The descriptions of the stories and behaviours are also very vivid and lead to helpful “visualisation”, making the entire book “alive”, never feeling like a reference book, but as a series of interesting (and surprising) stories — although it can also be read as a very useful, easily digestible reference book for anyone studying animal behaviour and emotions in Nonhuman Animals. There is also lots of practical advice about how to start observing animals or even how to challenge the cruel speciesist education system, which I am sure many young readers would appreciate, because it gives them a “place to go” after reading the book to begin applying its important lessons (this is the “guide” aspect referred to in the subtitle of the book).
In fact, I found the book so engaging with my “sponged” mind that I read its 225 pages in a single sitting. That should tell you a lot about its quality.
Poignant, Emotive, and Compassionate
The content of the book is what I expected from Marc: a close-up account of many examples where the rich emotional lives of many Nonhuman Animals are showcased, told in a very respectful and compassionate way. Nobody I know has defended the overwhelming truth that humans are not the only creatures who have emotions as Marc has done throughout his career, and I am so glad that now he has found, with Jeff’s help, a way to communicate this important insight to younger audiences.
For me, it’s so obvious that other animals feel the same emotions as we feel (from insects to bonobos) that I sometimes forget that not everyone is convinced yet because they have been indoctrinated in a speciesist society that has deflated their empathy and blinded them to this reality. However, young adults, by just having lived fewer years under the indoctrination of speciesism, are more likely to understand that other animals feel as they feel, and now, thanks to Marc and Jeff, they can get rid of their indoctrination sooner. Witnessing the many examples that the authors have compiled all over the book, their eyes will open (or the external forces that try to close them would be dissipated), and they will see the truth. This is as important as poignant, because they need to understand their rightful place on this planet if they are ever going to participate on it constructively.
The message the book conveys is not only “other animals feel like you do”. It also goes into ethics, suggesting what humans do right and do wrong, but in a way that allows the reader to arrive at the same conclusions without being forced to accept them. In this regard, the book is very respectful of the autonomy of the reader, without shying away from sending a strong message toward being more compassionate, respectful, and considerate with the rest of sentient beings we share this planet with.
Many of the concepts that Marc has been developing over the years, such as biocentric anthropomorphism, compassionate conservation, or animal well-being (in contrast to “welfare”), can be seen through the book — sometimes only in passing — gently introducing the young minds to these ideas without overwhelming them with too much “theory”.
With my intact older adult brain back on, I enjoyed the book enormously because it allowed me to revisit several of the amazing individual animals Marc has introduced me to throughout his writings — such as Jethro the dog, Octavia the octopus, Chantek the orangutan, David Greybeard the chimp, or, of course, Jasper the bear. There were also incredible stories that were new to me, and insights into Nonhuman Animals minds that were fascinating (I particularly remember the account of a dolphin swimming side-to-side like a shark as in a kind of playful mocking made in jest).
The stories about elephants, macaws, keas, wolves, crows, bumblebees, humpback whales, horses, dogs, fishes, iguanas, foxes, giraffes, orcas, manta rays, mule deers, zebras, lions, rats, dolphins, cows, or chickens, they are all so emotional and revealing, that even if I already knew many of them, they still got to me. There is nothing more emotional than feeling others through empathy, so Marc’s work has this power of activating natural empathy and applying it across species, which is perhaps one of the most essential tools for human redemption.
Love in Their Hearts should be read in all young adult schools because it contains important, poignant messages that will help character growth as well as use the rebellious spirit that teens naturally possess toward challenging the current unjust systems of oppression that have caused so much destruction on this planet and so much suffering to its sentient sphere. It’s not just an educational book about animals, but an eye-opening close-up introduction to all the “others” who have been wrongly ignored at best — or tragically abused at worst — which will open an essential “empathic eye” and expand humanity’s circle of compassion to its rightful size. One essential book that will excite new naturalists and help to educate every young person about how to be good.
Love in our hearts is all that it will take to feel the love in their hearts too.
